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Sega Genesis 3D engine update 4 Never can leave a good rabbit hole undug ! .. updates since last update : Changed frame buffer from a VDP tile friendly buffer to a linear buffer which needs CPU translation , which speedup drawing a LOT not having to... worry about tile boundaries albiet slows buffer sending to VRAM. The interior filling of triangles now is running at 1.5c ( 68k cycles ) per pixel ! however sending the buffer is twice as slow per byte as we need the CPU to send the buffer to VRAM to write to the tile format the VDP needs, rather than DMA directly to VRAM . Overall speedup 25% + as the drawing speedup is much greater than the frame buffer slow down. Optimised Line drawing and Triangle filling -near optimal now for the linear frame buffer. Triangle drawing might get a little bit more yet. Quad drawing is next on the list as that will speedup drawing quads. Some gains will come from been smart about partial clearing of RAM buffers and partial sending to VRAM buffers, rather than send the whole buffer. Vertice rotation and projection needs a lot of optimising .. i expect good gains to come from this - this is all in C at present and all calced in real time. Line and Triangle drawing are in assembly but all vertex manipulation is in C. #SGDK #MegaDrive #SegaGenesisshow more

Shannon Birt

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** Sega Genesis 3D engine Update 5 ** Added support for Quads - quads are faster than triangles for drawing 4 sided objects ( vs 2 triangles ) as theres larger filling runs before edges. Made multiple enhancements to Triangle and Quad drawing for speed. 27% faster than last Video for triangle drawing. Changed back to Non linear frame buffer + DMA for speed of frame buffer (fb) transfer. The two buffer systems ( Linear FB + CPU blit Vs Non Linear FB + DMA transfer ) I have competing and porting optimisations back to either for the meantime. Triangle drawing vertex calculation done in Assembly . Triangle and Quad functions now loop in Assembly saving stack calls from C. Next tasks, H40 mode for Faster DMA with centered screen , more optimisations in setup , more optimisations in cullling and more detail in general. #SGDK #SegaGenesis #SegaMegadrive

Sega Genesis 3D engine Update 5 Added support for Quads - quads are faster than triangles for drawing 4 sided objects ( vs 2 triangles ) as theres larger filling runs before edges. Made multiple enhancements to Triangle and Quad drawing for speed. 27% faster than last Video for triangle drawing. Changed back to Non linear frame buffer + DMA for speed of frame buffer (fb) transfer. The two buffer systems ( Linear FB + CPU blit Vs Non Linear FB + DMA transfer ) I have competing and porting optimisations back to either for the meantime. Triangle drawing vertex calculation done in Assembly . Triangle and Quad functions now loop in Assembly saving stack calls from C. Next tasks, H40 mode for Faster DMA with centered screen , more optimisations in setup , more optimisations in cullling and more detail in general. #SGDK #SegaGenesis #SegaMegadrive

Shannon Birt

17,150 views • 4 months ago

** 3D Engine Update 6 ** New Buffer System. 15-20% Faster !! Using Planes A and B interleaved horizontally we can get the best of all worlds with a near continuous frame buffer for fast Triangle & Quad writes and still use DMA for fast sending of the RAM frame buffer to VRAM. Normally you get one benefit without the other leading to tradeoffs. There is a caveat ofcourse, I lose a spare plane , however thats not a large concern for what im trying to achieve, i still have the full sprite load if i need to simulate ground etc - we can also multiplex sprites if needed. So each plane is full of half fill tiles ( 4 pixels set in each tile row ) , which are then slightly offset to make the full image. Also changed to H40 mode for faster DMA albiet centered view , plenty of Hud options for side panels etc. What is quite cool is the layout in VRAM is very similar to what you see on screen just with some striping . VRAM layout to the right. Theres no more VRAM used verse a normal double buffer , the trick is here to send the buffer in one frame always as theres no room for a double buffer in vram. I have to implement partial ofscreen drawing yet hence the snapping from front to back you see still . #SGDK #SegaGenesis #SegaMegadrive

3D Engine Update 6 New Buffer System. 15-20% Faster !! Using Planes A and B interleaved horizontally we can get the best of all worlds with a near continuous frame buffer for fast Triangle & Quad writes and still use DMA for fast sending of the RAM frame buffer to VRAM. Normally you get one benefit without the other leading to tradeoffs. There is a caveat ofcourse, I lose a spare plane , however thats not a large concern for what im trying to achieve, i still have the full sprite load if i need to simulate ground etc - we can also multiplex sprites if needed. So each plane is full of half fill tiles ( 4 pixels set in each tile row ) , which are then slightly offset to make the full image. Also changed to H40 mode for faster DMA albiet centered view , plenty of Hud options for side panels etc. What is quite cool is the layout in VRAM is very similar to what you see on screen just with some striping . VRAM layout to the right. Theres no more VRAM used verse a normal double buffer , the trick is here to send the buffer in one frame always as theres no room for a double buffer in vram. I have to implement partial ofscreen drawing yet hence the snapping from front to back you see still . #SGDK #SegaGenesis #SegaMegadrive

Shannon Birt

12,758 views • 4 months ago

** Sega Genesis 3D engine Day 2 ** Added solid filled triangles. Added colors ( full 15 color buffer ) . All code in C so far apart form the buffer clear and DMA buffer sending so should be some good speedups to come yet once line / triangle routines are ported to 68k Assembly. I've done basic filling optimisations in C such as where we can write longs eg fill 8 pixels at once for interior parts of the triangle the function will utilise that. Still using 3 divisions per triangle setup , I think i will see if I can use a cheaper reciprical multiplication instead. All rotations vertices are calculated live , in 2d space at present. #SGDK #SegaGenesis #SegaMegadrive

Sega Genesis 3D engine Day 2 Added solid filled triangles. Added colors ( full 15 color buffer ) . All code in C so far apart form the buffer clear and DMA buffer sending so should be some good speedups to come yet once line / triangle routines are ported to 68k Assembly. I've done basic filling optimisations in C such as where we can write longs eg fill 8 pixels at once for interior parts of the triangle the function will utilise that. Still using 3 divisions per triangle setup , I think i will see if I can use a cheaper reciprical multiplication instead. All rotations vertices are calculated live , in 2d space at present. #SGDK #SegaGenesis #SegaMegadrive

Shannon Birt

17,618 views • 4 months ago

** Sega Genesis 3D Engine Day 3 ** Blast Processing kicks In !! Converted the Line Drawing and Triangle drawing to 68k Assembly and gained 25% in the line drawing and 33% speedups in the triangle drawing vs C ( so far ) . The scheduler calculating the vertexs is still in C , just the drawing routines are now are in assembly . Possibly 5-10 % gains will come from the scheduler being in ASM also. The Line and Triangle drawing C code took some beating , it was surprising - particularly the line drawing to get a speed up over the C code in ASM. I guess its not too surprising as the C code was basically handling pointers and integers so I had to get exotic to find the speedups. Initially my ASM Line draw was 100% slower than the C code - the first pass conversion from C to ASM is always rough as its more about getting it working then refine later , but yeah 100% slower on first pass was brutal, after 4 hrs tweaking it was 25% faster than the C code so thats a good start - might get more yet. So added more squares and more triangles for load testing at the same frame rate. Its still not anything cohesive but right now focussing on performance in rendering to see how much can be pushed. As rendering will be the biggest cpu soak the faster that goes the better. The smaller triangles take about 1/3 the CPU time of the larger triangles at present so theres definately a fill rate limit vs the setup time to consider. The same would go for the squares been line framed - smaller ones would allow al lot more . #SGDK #SegaGenesis #SegaMegadrive

Sega Genesis 3D Engine Day 3 Blast Processing kicks In !! Converted the Line Drawing and Triangle drawing to 68k Assembly and gained 25% in the line drawing and 33% speedups in the triangle drawing vs C ( so far ) . The scheduler calculating the vertexs is still in C , just the drawing routines are now are in assembly . Possibly 5-10 % gains will come from the scheduler being in ASM also. The Line and Triangle drawing C code took some beating , it was surprising - particularly the line drawing to get a speed up over the C code in ASM. I guess its not too surprising as the C code was basically handling pointers and integers so I had to get exotic to find the speedups. Initially my ASM Line draw was 100% slower than the C code - the first pass conversion from C to ASM is always rough as its more about getting it working then refine later , but yeah 100% slower on first pass was brutal, after 4 hrs tweaking it was 25% faster than the C code so thats a good start - might get more yet. So added more squares and more triangles for load testing at the same frame rate. Its still not anything cohesive but right now focussing on performance in rendering to see how much can be pushed. As rendering will be the biggest cpu soak the faster that goes the better. The smaller triangles take about 1/3 the CPU time of the larger triangles at present so theres definately a fill rate limit vs the setup time to consider. The same would go for the squares been line framed - smaller ones would allow al lot more . #SGDK #SegaGenesis #SegaMegadrive

Shannon Birt

21,171 views • 4 months ago

** MEGA Parodius Scaling Effects Part 1 ** One of the big challenges with the Parodius Megadrive port is Stage 8's boss - The puffer-fish *Pooyan* with his full screen scaling effect. The goal is to be very close to the arcade (with extras on top ) so I thought lets tackle it head on to see how close we can get. I was also keen to jump into another scaling code rabit hole haha. Pyron pulled out all the stops and got me the source frames and reworked the BG tiles for this test - a big thankyou to him , Vector Orbitex is busy working on Stage 2 tracks so the team is working hard all round on this port. The MD has no sprite / background GFX scaling hardware , however the VDPs Vertical scroll can be updated per scanline to help vertical scaling on backgrounds, but there is a cpu cost to manage all the interupts so thats not free either. With the Horizontal scaling there is no help at all , apart from a semi-friendly packed pixel format for the cpu to work with, its not quite chunky format but better than planar format still for scaling. So its falls back to the 68k CPU to do all of the horizontal expansion which is the largest cpu cost. Basically drawing strips of either 1x, 2x, 3x or 4x wide columns at speed. So we are one week into this Boss's routine and you can see from the below video the horizontal scaling is implented ( vertical will be in the next update ) . We are scaling from 1x to 4x in the video below in 74 steps for testing . The column distributions are always a bit painfull to do - thankfully they are all worked out now. This is the third scaler I have built and the goal was with this one to make it really flexible for use in other projects also, sometimes when you optimise something to the last degree all the flexibility gets taken out of it. Currenty scaling at 12-25 FPS update here, I had some rules against some optimisations which I would use and some I wouldn't , thankfully we are a bit ahead of the Arcades animation frame rate here still and I may yet find optimisations that fit within the scope. We have vertical scaling and sprite spikes to add yet so Im hoping i can find a few more optimisations to offset things when they are implemented also. In a scale frame update we are processing close to 42000 pixels in ram before using DMA to send to VRAM . Using a 41x16 (656 tile scale buffer) - single buffered for now due to its size in VRAM. So thats nearly 21k in tiles ! I had to re-organise ram a bit to support a buffer of that size for the stage. The scaling function is written in 68k assembly , with a little C code handling the Vertical interupt code ( so the game logic can actually run & DMA updates etc ) . The DMA routines are in assembly also and customised for large chunk size ( big blocks of tiles ) which suits the scaler. I had some race conditions to sort out where the cpu was faster than DMA (sending tiles from RAM to VRAM ) and in some cases where it wasn't so it had to be balanced. We may be able to add more detail into the top and bottom of the background yet but its low priority for now until all the other bits are in !! #SGDK #SegaMegadrive #Genesis #Parodius

MEGA Parodius Scaling Effects Part 1 One of the big challenges with the Parodius Megadrive port is Stage 8's boss - The puffer-fish Pooyan with his full screen scaling effect. The goal is to be very close to the arcade (with extras on top ) so I thought lets tackle it head on to see how close we can get. I was also keen to jump into another scaling code rabit hole haha. Pyron pulled out all the stops and got me the source frames and reworked the BG tiles for this test - a big thankyou to him , Vector Orbitex is busy working on Stage 2 tracks so the team is working hard all round on this port. The MD has no sprite / background GFX scaling hardware , however the VDPs Vertical scroll can be updated per scanline to help vertical scaling on backgrounds, but there is a cpu cost to manage all the interupts so thats not free either. With the Horizontal scaling there is no help at all , apart from a semi-friendly packed pixel format for the cpu to work with, its not quite chunky format but better than planar format still for scaling. So its falls back to the 68k CPU to do all of the horizontal expansion which is the largest cpu cost. Basically drawing strips of either 1x, 2x, 3x or 4x wide columns at speed. So we are one week into this Boss's routine and you can see from the below video the horizontal scaling is implented ( vertical will be in the next update ) . We are scaling from 1x to 4x in the video below in 74 steps for testing . The column distributions are always a bit painfull to do - thankfully they are all worked out now. This is the third scaler I have built and the goal was with this one to make it really flexible for use in other projects also, sometimes when you optimise something to the last degree all the flexibility gets taken out of it. Currenty scaling at 12-25 FPS update here, I had some rules against some optimisations which I would use and some I wouldn't , thankfully we are a bit ahead of the Arcades animation frame rate here still and I may yet find optimisations that fit within the scope. We have vertical scaling and sprite spikes to add yet so Im hoping i can find a few more optimisations to offset things when they are implemented also. In a scale frame update we are processing close to 42000 pixels in ram before using DMA to send to VRAM . Using a 41x16 (656 tile scale buffer) - single buffered for now due to its size in VRAM. So thats nearly 21k in tiles ! I had to re-organise ram a bit to support a buffer of that size for the stage. The scaling function is written in 68k assembly , with a little C code handling the Vertical interupt code ( so the game logic can actually run & DMA updates etc ) . The DMA routines are in assembly also and customised for large chunk size ( big blocks of tiles ) which suits the scaler. I had some race conditions to sort out where the cpu was faster than DMA (sending tiles from RAM to VRAM ) and in some cases where it wasn't so it had to be balanced. We may be able to add more detail into the top and bottom of the background yet but its low priority for now until all the other bits are in !! #SGDK #SegaMegadrive #Genesis #Parodius

Shannon Birt

25,545 views • 7 months ago

YO ADRIAN! I DID IT! Update on my TMNT SNES port. This is the most extensive OAM overhaul I've ever done with a port, and I'm damn proud of myself! Lot of reverse engineering with the OG OAM engine, and I was finally able to incorporate a new method of writing to the buffer. This game does some heavy ADC/TAX for OAM buffer rotation to try to work around the sprite flicker. But that ADC/TAX rotation was complicating things for me when I was trying to incorporate a 16-bit index engine. What is also tricky, is that this game uses 8x16 sprites, and what is special on the NES, its hardware creates the bottom 8x8 sprite tile, without the need of the OAM to have it present. You can't do that on the SNES, you have to create that 2nd 8x8 sprite tile within code. The reason this is such a big deal, is before with 8x16 titles i've worked on, I would first simply copy the games original oam buffer to my snes buffer, but that addded alot of extra cpu time, this is present in my Legend of Zelda SNES port. Later ports I've done, I don't do that anymore, I modify the games original storage of OAM values, and send them directly to my custom snes OAM buffer, eliminating extra cpu cycles. So what's the big deal? My method of doing 8x16 sprites, is using my first 256 byte oam buffer for the top 8x8 tile, and my second 256 byte oam buffer for the bottom 8x8 tile. The issue I was having, was errors with sprite priority when sprites overlap each other. I noticed this right away during the dam sequence where the turtles have to disarm the bombs. Here is a before and after my port. Now I can finally move on with the port! 🙂

YO ADRIAN! I DID IT! Update on my TMNT SNES port. This is the most extensive OAM overhaul I've ever done with a port, and I'm damn proud of myself! Lot of reverse engineering with the OG OAM engine, and I was finally able to incorporate a new method of writing to the buffer. This game does some heavy ADC/TAX for OAM buffer rotation to try to work around the sprite flicker. But that ADC/TAX rotation was complicating things for me when I was trying to incorporate a 16-bit index engine. What is also tricky, is that this game uses 8x16 sprites, and what is special on the NES, its hardware creates the bottom 8x8 sprite tile, without the need of the OAM to have it present. You can't do that on the SNES, you have to create that 2nd 8x8 sprite tile within code. The reason this is such a big deal, is before with 8x16 titles i've worked on, I would first simply copy the games original oam buffer to my snes buffer, but that addded alot of extra cpu time, this is present in my Legend of Zelda SNES port. Later ports I've done, I don't do that anymore, I modify the games original storage of OAM values, and send them directly to my custom snes OAM buffer, eliminating extra cpu cycles. So what's the big deal? My method of doing 8x16 sprites, is using my first 256 byte oam buffer for the top 8x8 tile, and my second 256 byte oam buffer for the bottom 8x8 tile. The issue I was having, was errors with sprite priority when sprites overlap each other. I noticed this right away during the dam sequence where the turtles have to disarm the bombs. Here is a before and after my port. Now I can finally move on with the port! 🙂

infidelity

13,423 views • 11 months ago

Jesus Christ, jnmartin has officially implemented his first big improvement over the N64 original for the Sega Dreamcast port of Mario Kart 64! Now the jumpotron monitor screens in Wario Stadium and and Luigi Raceway are updating at a full 30FPS, or 6x the framerate of the N64! ...and he's doing this entirely in software with the DC's SH4 CPU performing slow, direct VRAM reads from the framebuffer into a temporary buffer in system RAM which is later passed to OpenGL which transfers it back into VRAM to update the jumpotron texture with... and the freaking Dreamcast doesn't drop a frame doing all this shit! Might want to keep that in mind, as a community... That accessing texture memory or the framebuffer directly from the SH4 via the "uint16_t vram_s[]" symbol that the video API within KallistiOS exposes, while comparatively slow, is not actually so slow as to be unrealistic for a well-optimized game to do anything useful with... very interesting!

Jesus Christ, jnmartin has officially implemented his first big improvement over the N64 original for the Sega Dreamcast port of Mario Kart 64! Now the jumpotron monitor screens in Wario Stadium and and Luigi Raceway are updating at a full 30FPS, or 6x the framerate of the N64! ...and he's doing this entirely in software with the DC's SH4 CPU performing slow, direct VRAM reads from the framebuffer into a temporary buffer in system RAM which is later passed to OpenGL which transfers it back into VRAM to update the jumpotron texture with... and the freaking Dreamcast doesn't drop a frame doing all this shit! Might want to keep that in mind, as a community... That accessing texture memory or the framebuffer directly from the SH4 via the "uint16_t vram_s[]" symbol that the video API within KallistiOS exposes, while comparatively slow, is not actually so slow as to be unrealistic for a well-optimized game to do anything useful with... very interesting!

Falco Girgis

24,032 views • 1 year ago

** Sega Genesis 3D Engine Update 8 ** Significant improvements all round as you can see and hear from the last update !! Foremost - A huge thanks to Toni Gálvez - Megastyle - BG. who has joined the project to create a bit of 16bit low poly magic. Toni's an Amiga fan but also crazy about game dev in general, he's worked on GBC, GBA, PC, MD, PSP, C64, CPC, MSX... and others. Gaming titles include War Times, Metal Gear, Rocketman, Tintin & Asterix to name a few. He's provided the great new ship model you see on screen - new striped buildings, all the backgrounds / palettes etc. There's a lot of models he's given me which need to be added, also he will be planning a lot of the level design. Very happy to have him help me turn this into something more than a tech demo as I have my hands tied pushing the MD as far as it can go haha - there is no cpu cycle to be spared. Also many thanks to my good friend CYBERDEOUS - Crouzet Laurent for the Music for this showing , I wanted to have the music load occurring so we have a realistic benchmark for performance and he was only too obliging. If you're into MD chiptunes check him out !! Since last update : New player model , substantially more detailed than the Arwing. Last update had a 23 triangle Arwing , this update has a 39 triangle custom model from Toni. We had several to choose from , others will be used for enemies . 3D Buffer size increased 25% to 256x160. This was quite tricky as I'm close to the DMA limit even with an extended vblank . Spent a few days thinking of how to do this as like anything retro every solution has a drawback, finally got a workable solution. It makes a big difference to have a bit more vertical height . Z Rotation added ( the screen tilting left to right ) , small hit to vertex transform on cpu thanks to look up tables doing the heavy lifting, saving 4 multiplies per vertex. Multiple speed ups in rendering code. Onscreen paths with no range checking used until Z is close enough to cause clipping , partial onscreen drawing pathes that need to check boundaries, quad rendering completely rewritten - was very very painfull to get right . I found out the hard way that things are great when they are not rotating in the Z axis haha . Partial buffer draw optimisations - which have helped with the massive dma load , sending up to a 20kb buffer in a single frame needs a lot of optimisation. Min / Max tile lines are analysed and only sent if dirtied , reducing most buffer swaps substantially. Still some issues to sort out , at times you can see the flicker near top of screen when frames are near full height . I need to optimise that a bit. Due to the onscreen buffer system a full Sprite background had to be implemented almost Neo Geo style. This flips the usual MD rendering system on its head as it uses both foreground and background layers for a foreground 3d plane and sprites for the background. This presents a few issues, one is to get a tilt effect on the background by using narrow sprites (16x32) we run out of sprites when trying to cover the screen. Thankfully the MD is not limited to 80 sprites, to fix this a 114 sprite multiplexor is used to draw the background, its completely made up of 16x32 sprites ! Why do things this way ? speed . Its the interleaved foreground/background layers that allow a double buffered ram system writing to write to vram using dma in a completely linear fashion - virtually no tile translation needed. The negative is you have no planes for the background, that's where the sprites come in . Thanks to H40 mode we still have a few sprites we can use for effects in the forground also . Thankfully we can implement a fairly good tilt still for the background using sprites, in future updates this will be able to move horizontally also and a bit of vertical movement. XGM1 music driver in use to simulate music cpu load, XGM2 unfortunately with the massive DMA needed to shift the 3d buffers would slow down at times rendering it unusable, XGM1 plays at full speed - albiet with a bit more of a cpu hit. Together with the sprite multiplexor and the music driver active theres a 10 % hit to cpu so I've had to play around with draw distances / object heights and other optimisations to offset that. Not to mention the larger buffer takes more cpu to fill also. Everything is placeholder so will be changed with proper stage design. We are averaging 20 FPS in the current video, I'll push for more as always !! Progress continues on my other projects , updates soon on those - retirement can't come quick enough . #SGDK #SegaGenesis #SegaMegadrive

Sega Genesis 3D Engine Update 8 Significant improvements all round as you can see and hear from the last update !! Foremost - A huge thanks to Toni Gálvez - Megastyle - BG. who has joined the project to create a bit of 16bit low poly magic. Toni's an Amiga fan but also crazy about game dev in general, he's worked on GBC, GBA, PC, MD, PSP, C64, CPC, MSX... and others. Gaming titles include War Times, Metal Gear, Rocketman, Tintin & Asterix to name a few. He's provided the great new ship model you see on screen - new striped buildings, all the backgrounds / palettes etc. There's a lot of models he's given me which need to be added, also he will be planning a lot of the level design. Very happy to have him help me turn this into something more than a tech demo as I have my hands tied pushing the MD as far as it can go haha - there is no cpu cycle to be spared. Also many thanks to my good friend CYBERDEOUS - Crouzet Laurent for the Music for this showing , I wanted to have the music load occurring so we have a realistic benchmark for performance and he was only too obliging. If you're into MD chiptunes check him out !! Since last update : New player model , substantially more detailed than the Arwing. Last update had a 23 triangle Arwing , this update has a 39 triangle custom model from Toni. We had several to choose from , others will be used for enemies . 3D Buffer size increased 25% to 256x160. This was quite tricky as I'm close to the DMA limit even with an extended vblank . Spent a few days thinking of how to do this as like anything retro every solution has a drawback, finally got a workable solution. It makes a big difference to have a bit more vertical height . Z Rotation added ( the screen tilting left to right ) , small hit to vertex transform on cpu thanks to look up tables doing the heavy lifting, saving 4 multiplies per vertex. Multiple speed ups in rendering code. Onscreen paths with no range checking used until Z is close enough to cause clipping , partial onscreen drawing pathes that need to check boundaries, quad rendering completely rewritten - was very very painfull to get right . I found out the hard way that things are great when they are not rotating in the Z axis haha . Partial buffer draw optimisations - which have helped with the massive dma load , sending up to a 20kb buffer in a single frame needs a lot of optimisation. Min / Max tile lines are analysed and only sent if dirtied , reducing most buffer swaps substantially. Still some issues to sort out , at times you can see the flicker near top of screen when frames are near full height . I need to optimise that a bit. Due to the onscreen buffer system a full Sprite background had to be implemented almost Neo Geo style. This flips the usual MD rendering system on its head as it uses both foreground and background layers for a foreground 3d plane and sprites for the background. This presents a few issues, one is to get a tilt effect on the background by using narrow sprites (16x32) we run out of sprites when trying to cover the screen. Thankfully the MD is not limited to 80 sprites, to fix this a 114 sprite multiplexor is used to draw the background, its completely made up of 16x32 sprites ! Why do things this way ? speed . Its the interleaved foreground/background layers that allow a double buffered ram system writing to write to vram using dma in a completely linear fashion - virtually no tile translation needed. The negative is you have no planes for the background, that's where the sprites come in . Thanks to H40 mode we still have a few sprites we can use for effects in the forground also . Thankfully we can implement a fairly good tilt still for the background using sprites, in future updates this will be able to move horizontally also and a bit of vertical movement. XGM1 music driver in use to simulate music cpu load, XGM2 unfortunately with the massive DMA needed to shift the 3d buffers would slow down at times rendering it unusable, XGM1 plays at full speed - albiet with a bit more of a cpu hit. Together with the sprite multiplexor and the music driver active theres a 10 % hit to cpu so I've had to play around with draw distances / object heights and other optimisations to offset that. Not to mention the larger buffer takes more cpu to fill also. Everything is placeholder so will be changed with proper stage design. We are averaging 20 FPS in the current video, I'll push for more as always !! Progress continues on my other projects , updates soon on those - retirement can't come quick enough . #SGDK #SegaGenesis #SegaMegadrive

Shannon Birt

34,361 views • 1 month ago

*** Parodius Update - LAZERS !! *** How many sprites do we have to use on the Sega Genesis to make 4 x 160 pixel wide lazers ?? 10 ? 20 ? ZERO !! Which is really great as when the options overlap all with Lazers using sprites would have lead to sprite severe overload / dropout otherwise. So yes we have some raster trickery going on . I think this might take the cake for the most exotic effect Ive added just for a power up type haha. Breaking down the effect. 1.) Lazer tile rows ( the tile rows the lazers are currently on ) are copied to an offscreen area of the plane . I used the DMA VRAM to VRAM copy mode for this. You can see these offscreen rows just above the Game Videos window in the Plane A tilemap view. 2.) Then a solid block of Lazer colored tiles is drawn at the position of the Lazer horizontally in the offscreen buffer we just copied too - these are 8x8 tiles. 3.) Then onscreen when as the display is being drawn we change to the Lazers row at the correct pixel line offset for exactly 1 scanline then change back to the normal screens next row. I'm using the Horizontal interupt system developed in SOTA for handling the interupts for this. The technique used has been done before on the NES ( Salamander tech demo ) , as usual some of the best techniques come from the 8 bit systems , still it presented challenges getting it working on the MD. These irregular spaced interupts on the Genesis are a little bit of a problem too . All the height sorting has to be done on the frame before. Whats very interesting about the VRAM to VRAM copy DMA (Copy DMA) is it runs asynchronous to the CPU. Normally ROM/RAM to VRAM write DMA (Write DMA) halts the CPU during the send operation but with a Copy DMA I can pipeline one Copy DMA setup while the previous one is copying still . So even though the Copy DMA is 1/2 the speed of a Write DMA with the pipelining and no stalling its probably on par or better in some cases , where a copy makes sense to use. Theres still need some fine tuning , might make smaller lazers with more breaks etc. The Lazers can be full screen width , or narrow as we want so bit of fine tuning here to come. Pyron Vector Orbitex #Parodius #SegaMegadrive #SegaGenesis #SGDK

* Parodius Update - LAZERS !! * How many sprites do we have to use on the Sega Genesis to make 4 x 160 pixel wide lazers ?? 10 ? 20 ? ZERO !! Which is really great as when the options overlap all with Lazers using sprites would have lead to sprite severe overload / dropout otherwise. So yes we have some raster trickery going on . I think this might take the cake for the most exotic effect Ive added just for a power up type haha. Breaking down the effect. 1.) Lazer tile rows ( the tile rows the lazers are currently on ) are copied to an offscreen area of the plane . I used the DMA VRAM to VRAM copy mode for this. You can see these offscreen rows just above the Game Videos window in the Plane A tilemap view. 2.) Then a solid block of Lazer colored tiles is drawn at the position of the Lazer horizontally in the offscreen buffer we just copied too - these are 8x8 tiles. 3.) Then onscreen when as the display is being drawn we change to the Lazers row at the correct pixel line offset for exactly 1 scanline then change back to the normal screens next row. I'm using the Horizontal interupt system developed in SOTA for handling the interupts for this. The technique used has been done before on the NES ( Salamander tech demo ) , as usual some of the best techniques come from the 8 bit systems , still it presented challenges getting it working on the MD. These irregular spaced interupts on the Genesis are a little bit of a problem too . All the height sorting has to be done on the frame before. Whats very interesting about the VRAM to VRAM copy DMA (Copy DMA) is it runs asynchronous to the CPU. Normally ROM/RAM to VRAM write DMA (Write DMA) halts the CPU during the send operation but with a Copy DMA I can pipeline one Copy DMA setup while the previous one is copying still . So even though the Copy DMA is 1/2 the speed of a Write DMA with the pipelining and no stalling its probably on par or better in some cases , where a copy makes sense to use. Theres still need some fine tuning , might make smaller lazers with more breaks etc. The Lazers can be full screen width , or narrow as we want so bit of fine tuning here to come. Pyron Vector Orbitex #Parodius #SegaMegadrive #SegaGenesis #SGDK

Shannon Birt

16,162 views • 11 months ago

*** Mega Parodius Sega Megadrive Update *** Lately I've been having some fun seeing how far we can push the Parodius game engine . This is not arcade accurate - just for testing, decreased bullet timers and upped the bullet count to see what would happen re cpu usage when things are made a lot busier ! Maybe something like this could be insane mode in the options etc. Since last update we are a lot more optimised under the hood . The C based sprite engine, particularly visibility checking was speedup , overall 25 % faster. Then re-wrote the sprite engine completely in 68k assembly , 30% faster again. It took about 3 days and 1500 lines of assembly , thankfully the gains were worth it. All these gains will be back ported to S.O.T.A also as its using the same sprite engine. Usage is around 19% of cpu per frame with a full sprite load - 33 % cpu left in the busiest frame currently . Parodius is using a write the sprite list every frame type engine , so priority and meta-sprite objects can be handled with ease albiet its still a bit slower than static allocation sprite engines such as the one in lufthoheit but this is a bit easier to code for in the long run. All collision checks are been done , we are using a spatial grid system to get the collision checks done faster than a brute force approach . To get to maximum sprite count destruction is disabled in the video. We hit 80 sprites onscreen in this sequence , the sprite counter is one the Left side. We use about 16 sprites in the top hud and water line , about 21 for player attacks / missiles / shots / options . Up to 35 bullets + enemies . No lazer usage here as the Lazers use zero sprites thanks to the raster tricks , this video is all about the sprites ! Improved the water line when the Catboss is active , as he is Sprites + Forground we are doing some tile rotation tricks eg bit scrolling to give the impression of parrallax at that point . Vector Orbitex has updated the stage 1 music again and has made things even higher quality , hes mixed pcm and fm channels together to create higher quality orchestral hits for example . Pyron has started converting assets from stage 2/3 , some amazing work there . Hes well ahead of me at present which is a good thing. Still lots of incomplete animations missing logic etc , its slow going with RL getting in the way haha and 2 other projects !! Still its fun !! #SGDK #SegaMegadrive #SegaGenesis #Parodius

* Mega Parodius Sega Megadrive Update * Lately I've been having some fun seeing how far we can push the Parodius game engine . This is not arcade accurate - just for testing, decreased bullet timers and upped the bullet count to see what would happen re cpu usage when things are made a lot busier ! Maybe something like this could be insane mode in the options etc. Since last update we are a lot more optimised under the hood . The C based sprite engine, particularly visibility checking was speedup , overall 25 % faster. Then re-wrote the sprite engine completely in 68k assembly , 30% faster again. It took about 3 days and 1500 lines of assembly , thankfully the gains were worth it. All these gains will be back ported to S.O.T.A also as its using the same sprite engine. Usage is around 19% of cpu per frame with a full sprite load - 33 % cpu left in the busiest frame currently . Parodius is using a write the sprite list every frame type engine , so priority and meta-sprite objects can be handled with ease albiet its still a bit slower than static allocation sprite engines such as the one in lufthoheit but this is a bit easier to code for in the long run. All collision checks are been done , we are using a spatial grid system to get the collision checks done faster than a brute force approach . To get to maximum sprite count destruction is disabled in the video. We hit 80 sprites onscreen in this sequence , the sprite counter is one the Left side. We use about 16 sprites in the top hud and water line , about 21 for player attacks / missiles / shots / options . Up to 35 bullets + enemies . No lazer usage here as the Lazers use zero sprites thanks to the raster tricks , this video is all about the sprites ! Improved the water line when the Catboss is active , as he is Sprites + Forground we are doing some tile rotation tricks eg bit scrolling to give the impression of parrallax at that point . Vector Orbitex has updated the stage 1 music again and has made things even higher quality , hes mixed pcm and fm channels together to create higher quality orchestral hits for example . Pyron has started converting assets from stage 2/3 , some amazing work there . Hes well ahead of me at present which is a good thing. Still lots of incomplete animations missing logic etc , its slow going with RL getting in the way haha and 2 other projects !! Still its fun !! #SGDK #SegaMegadrive #SegaGenesis #Parodius

Shannon Birt

16,084 views • 8 months ago

** Mega Parodius Update ( MegaDrive / Genesis ) ** 2 vid updates - In the first the Vic Viper players ship is heavily damaged .. only the bomb bay is operational ... so the viper goes on a bomb *blast* processing rampage !! ... This shows enemy destruction and some polishing of the bomb effect. The 2nd vid shows VRAM handling of objects with the tile viewer opened below the gameplay window. You can see objects load in , then as only the burning chests remain those animations are shifted live to maximise free object buffer. Progress since last progress vid : All collisions now implemented : Enemy to Player added , Bomb to Enemy added, Enemy Destruction added. Auto Defragging VRAM system implemented for Enemy Objects. Supports variable slot size also to maximise tile space . Fixed slot sizes wouldn't allow enough slots as they would need to be too large to cover all objects. Without defragging the VRAM would become like swiss cheese after a few screens of enemies also making larger slots difficult to allocate. Vram was getting tight due to things like the Blue Bell Bomb / White Bell text needing a reserved amount of vram ( as they can occur anywhere in the level via powerups ) . Theres also theres quite a bit of variety in Level 1 with warmup enemies , bottle enemies, chickens, crabs, orcas, chests, bees, penguin bathes, walking penguins, bouncing heads etc. We are also using all the arcade assets without trying to cut frames. It can't be loaded all at once so a dynamic system is needed. The enemy object buffer is 444 tiles presently for Level 1 , but the Catboss for example takes 308 when he's onscreen so things can get squeezed. For Mega versions of levels I wanted to ramp things up so that might mean we need more diversity in places than for the arcade accurate option , this system will help that also. The system can stream animation or utilise static animation if vram allows. Seems a mundane thing but sloppy vram management is the achiles heal of GFX diversity in a retro game . To help reduce the Bell effects VRAM buffer , Blue Bomb tiles required reduced to 120 tiles Max ( was 172 ) with no loss of quality . I've also reduced the sprite count by 6 sprites overall - down to 46 sprites used at max frame size. Lots more action / enemies to add yet but particularly the VRAM handling had to be improved before we can implement everything so glad thats in place now. Pyron and Vector Orbitex have been busy with upcoming GFX / Audion for the port , as always I'm very gratefull to have these Masters working with me on the port . #SGDK #Parodius #SegaMegadrive #SegaGenesis

Mega Parodius Update ( MegaDrive / Genesis ) 2 vid updates - In the first the Vic Viper players ship is heavily damaged .. only the bomb bay is operational ... so the viper goes on a bomb blast processing rampage !! ... This shows enemy destruction and some polishing of the bomb effect. The 2nd vid shows VRAM handling of objects with the tile viewer opened below the gameplay window. You can see objects load in , then as only the burning chests remain those animations are shifted live to maximise free object buffer. Progress since last progress vid : All collisions now implemented : Enemy to Player added , Bomb to Enemy added, Enemy Destruction added. Auto Defragging VRAM system implemented for Enemy Objects. Supports variable slot size also to maximise tile space . Fixed slot sizes wouldn't allow enough slots as they would need to be too large to cover all objects. Without defragging the VRAM would become like swiss cheese after a few screens of enemies also making larger slots difficult to allocate. Vram was getting tight due to things like the Blue Bell Bomb / White Bell text needing a reserved amount of vram ( as they can occur anywhere in the level via powerups ) . Theres also theres quite a bit of variety in Level 1 with warmup enemies , bottle enemies, chickens, crabs, orcas, chests, bees, penguin bathes, walking penguins, bouncing heads etc. We are also using all the arcade assets without trying to cut frames. It can't be loaded all at once so a dynamic system is needed. The enemy object buffer is 444 tiles presently for Level 1 , but the Catboss for example takes 308 when he's onscreen so things can get squeezed. For Mega versions of levels I wanted to ramp things up so that might mean we need more diversity in places than for the arcade accurate option , this system will help that also. The system can stream animation or utilise static animation if vram allows. Seems a mundane thing but sloppy vram management is the achiles heal of GFX diversity in a retro game . To help reduce the Bell effects VRAM buffer , Blue Bomb tiles required reduced to 120 tiles Max ( was 172 ) with no loss of quality . I've also reduced the sprite count by 6 sprites overall - down to 46 sprites used at max frame size. Lots more action / enemies to add yet but particularly the VRAM handling had to be improved before we can implement everything so glad thats in place now. Pyron and Vector Orbitex have been busy with upcoming GFX / Audion for the port , as always I'm very gratefull to have these Masters working with me on the port . #SGDK #Parodius #SegaMegadrive #SegaGenesis

Shannon Birt

13,463 views • 7 months ago

** MEGA Parodius Scaling Effects Part 2 ** Well - this is the BIG one - literally !! Huge thanks to my team Pyron & Vector Orbitex for their efforts. Pyron has provided all the source frames for Puyon and his spikes / explosion and a lot of analysis video on how the spikes behave / move which was really helpful. Pyron also used his CRT setup for this video as we felt an emulator video would not do it justice - running on 100% real MD hardware FTW. Vector has provided the catchy boss music and its sounding great - as always ! The coding on this has been a bit insane - things done since part 1 post previous: Implemented dual buffering - Last video was single buffered - so VRAM is very tight now , we only have about 40/2048 tiles free. For the longest time I didn't think it would fit - I found a vram jigsaw puzzle that made it work in the end. Double buffering has cleaned up the stability of the animation and matches the arcade scaling effect now albiet costing 2x more VRAM . Vertical Scaling Implemented - the vertical scaler was taken from Lufthoheit ( my other shooter ) and its heavily optimised to reduce cpu usage. During the scaling the vertical scaler partitions the 68k processor registers into 2 sets, 4 registers are allocated to feeding the fast horizontal interrupt (h-int) that drives the vertical scaling , remaining 12 registers are for the horizontal scaler running in the background. This setup is much faster than normal backup / restore register methods, as we do not need to backup / restore registers in the h-int which would double CPU costs. The catch is the momment any background routine tries to use the H-ints registers it would break things so it has to be carefully timed. Added the spike projectiles - this was very tricky to get close to the arcade, they are semi heat seeking missiles basically and hence needed code that worked out angle differences to player at speed theres no time for arc-tan or similar so it uses faster lookup tables to work out the angles . They speed up over time and get larger and whats more we can't keep all the scales in VRAM - we have room for 2 spike buffers only. Also what was a real pain was working out scaled coordinates for the circular launch of the spikes . Added Fish Damage - Shock frame and Explosion frames from Arcade . Very proud of the fact we have the full arcade quality explosion is which is fully scaled also. Added Temporal Masking - which is fancy wording for don't draw nothing to buffer if nothing is there already there for the scaling . So empty Corners and edges can be optimised out to lower cpu costs and rom costs. I had to make some scripting for this and work out what areas did not need drawing at all in the frame, which should be force cleared by cpu and which areas should just be copied from rom. This reduced rom size by 30 kb and with a bit more work we could extend that to 60 kb & get a bit more speedup even doing so. Added a frame limiter . In the last video update we let the 68k burn hot and just pump out frames as fast as it could - here we match the arcade animation rate which does leave the cpu idling at times , particularly in the smaller frames - even at large though we could be running the animation 25 % faster , issue is though that would speed up the game logic and make it less arcade accurate. We had some real bullet / Spike hell simulations going without the limiter but yeah we had to tone it down a bit. Maybe in a hardcore mode we could let it run wild though ! Code is 95% 68k assembly with about 5% C code (v-int as its cold path ) driving things . This sort of thing needs all the speed it can get !! Well now after all that I can return to finish off Level 1 haha - just a wee sidetrack there . No doubt we will polish stage 8 boss some more in time too !! #SegaMegadrive #SegaGenesis #Parodius #SGDK

MEGA Parodius Scaling Effects Part 2 Well - this is the BIG one - literally !! Huge thanks to my team Pyron & Vector Orbitex for their efforts. Pyron has provided all the source frames for Puyon and his spikes / explosion and a lot of analysis video on how the spikes behave / move which was really helpful. Pyron also used his CRT setup for this video as we felt an emulator video would not do it justice - running on 100% real MD hardware FTW. Vector has provided the catchy boss music and its sounding great - as always ! The coding on this has been a bit insane - things done since part 1 post previous: Implemented dual buffering - Last video was single buffered - so VRAM is very tight now , we only have about 40/2048 tiles free. For the longest time I didn't think it would fit - I found a vram jigsaw puzzle that made it work in the end. Double buffering has cleaned up the stability of the animation and matches the arcade scaling effect now albiet costing 2x more VRAM . Vertical Scaling Implemented - the vertical scaler was taken from Lufthoheit ( my other shooter ) and its heavily optimised to reduce cpu usage. During the scaling the vertical scaler partitions the 68k processor registers into 2 sets, 4 registers are allocated to feeding the fast horizontal interrupt (h-int) that drives the vertical scaling , remaining 12 registers are for the horizontal scaler running in the background. This setup is much faster than normal backup / restore register methods, as we do not need to backup / restore registers in the h-int which would double CPU costs. The catch is the momment any background routine tries to use the H-ints registers it would break things so it has to be carefully timed. Added the spike projectiles - this was very tricky to get close to the arcade, they are semi heat seeking missiles basically and hence needed code that worked out angle differences to player at speed theres no time for arc-tan or similar so it uses faster lookup tables to work out the angles . They speed up over time and get larger and whats more we can't keep all the scales in VRAM - we have room for 2 spike buffers only. Also what was a real pain was working out scaled coordinates for the circular launch of the spikes . Added Fish Damage - Shock frame and Explosion frames from Arcade . Very proud of the fact we have the full arcade quality explosion is which is fully scaled also. Added Temporal Masking - which is fancy wording for don't draw nothing to buffer if nothing is there already there for the scaling . So empty Corners and edges can be optimised out to lower cpu costs and rom costs. I had to make some scripting for this and work out what areas did not need drawing at all in the frame, which should be force cleared by cpu and which areas should just be copied from rom. This reduced rom size by 30 kb and with a bit more work we could extend that to 60 kb & get a bit more speedup even doing so. Added a frame limiter . In the last video update we let the 68k burn hot and just pump out frames as fast as it could - here we match the arcade animation rate which does leave the cpu idling at times , particularly in the smaller frames - even at large though we could be running the animation 25 % faster , issue is though that would speed up the game logic and make it less arcade accurate. We had some real bullet / Spike hell simulations going without the limiter but yeah we had to tone it down a bit. Maybe in a hardcore mode we could let it run wild though ! Code is 95% 68k assembly with about 5% C code (v-int as its cold path ) driving things . This sort of thing needs all the speed it can get !! Well now after all that I can return to finish off Level 1 haha - just a wee sidetrack there . No doubt we will polish stage 8 boss some more in time too !! #SegaMegadrive #SegaGenesis #Parodius #SGDK

Shannon Birt

26,902 views • 6 months ago

Duffy: If we can help someone as they are getting on the aircraft that might need some help putting their bag in the overhead bin and you’re a little stronger/buffer, you’ve been lifting, stand up and offer to grab that bag and put it up for someone who is having a difficult time.

Duffy: If we can help someone as they are getting on the aircraft that might need some help putting their bag in the overhead bin and you’re a little stronger/buffer, you’ve been lifting, stand up and offer to grab that bag and put it up for someone who is having a difficult time.

Acyn

96,793 views • 9 months ago

"The purest form of ambition and most intense source of energy in the business is the founder CEO. Every next concentric circle of management beyond the founder CEO has the potential to be an order of magnitude drop off in intensity. And that is f*cking dangerous. You don't need to buffer people from the intensity of the CEO—you need to absolutely mirror that intensity. There is an infinite supply of people under you who will buffer other team members from the intensity of the demands. Your job is not to be one of those buffers. If you want to achieve greatness, if you want an extraordinary outcome, then you have to relentlessly inject energy at every single step. Teams will always optimize for local comfort over company outcomes. Your job as an executive, as a leader, is to fight that entropy tooth and nail, every single day." — Matt MacInnis (Matt MacInnis), Rippling CPO/COO

"The purest form of ambition and most intense source of energy in the business is the founder CEO. Every next concentric circle of management beyond the founder CEO has the potential to be an order of magnitude drop off in intensity. And that is f*cking dangerous. You don't need to buffer people from the intensity of the CEO—you need to absolutely mirror that intensity. There is an infinite supply of people under you who will buffer other team members from the intensity of the demands. Your job is not to be one of those buffers. If you want to achieve greatness, if you want an extraordinary outcome, then you have to relentlessly inject energy at every single step. Teams will always optimize for local comfort over company outcomes. Your job as an executive, as a leader, is to fight that entropy tooth and nail, every single day." — Matt MacInnis (Matt MacInnis), Rippling CPO/COO

Lenny Rachitsky

75,835 views • 8 months ago

🇫🇷 French opposition leader Mélenchon: Israel's Lebanon “buffer zone” is annexation, France should have intervened Jean-Luc Mélenchon, leader of France's left-wing La France Insoumise party, spoke at a Franco-Lebanese rally in Paris, accusing successive French governments of cowardice and describing Israel's buffer zone in southern Lebanon as "annexation". "From the very first second, all those who did not react immediately when Netanyahu said he wanted to create a buffer zone are guilty," he said. "There is no possibility in international law for a state to create a buffer zone in its neighbour. This is called annexation." France, as guarantor of the UNIFIL mission, had a legal obligation to act and instead ordered its troops to withdraw, Mélenchon argued. "Intervening is not withdrawing." He said Israel's true aims extend beyond security — accusing Netanyahu's government of seeking control over southern Lebanon's offshore gas reserves and the Litani River's water resources, linking the operation to Israeli ambitions in the Golan Heights. He called on the crowd to back a European petition to suspend trade agreements with Israel for as long as it occupies Lebanese territory. "Lebanon has the inalienable right to be free and not to have a single square meter of its territory occupied by anyone. Long live Lebanon, long live peace. Down with the genocide."

🇫🇷 French opposition leader Mélenchon: Israel's Lebanon “buffer zone” is annexation, France should have intervened Jean-Luc Mélenchon, leader of France's left-wing La France Insoumise party, spoke at a Franco-Lebanese rally in Paris, accusing successive French governments of cowardice and describing Israel's buffer zone in southern Lebanon as "annexation". "From the very first second, all those who did not react immediately when Netanyahu said he wanted to create a buffer zone are guilty," he said. "There is no possibility in international law for a state to create a buffer zone in its neighbour. This is called annexation." France, as guarantor of the UNIFIL mission, had a legal obligation to act and instead ordered its troops to withdraw, Mélenchon argued. "Intervening is not withdrawing." He said Israel's true aims extend beyond security — accusing Netanyahu's government of seeking control over southern Lebanon's offshore gas reserves and the Litani River's water resources, linking the operation to Israeli ambitions in the Golan Heights. He called on the crowd to back a European petition to suspend trade agreements with Israel for as long as it occupies Lebanese territory. "Lebanon has the inalienable right to be free and not to have a single square meter of its territory occupied by anyone. Long live Lebanon, long live peace. Down with the genocide."

Drop Site

135,411 views • 4 months ago

** SEGA GENESIS / MEGADRIVE Software Scaling + Rotation *** Sega Megadrive can't scale backgrounds and rotate sprites in software at the same time ?? - hold my beer !! After Scaling I've been tinkering with Rotating sprites in software and I think it looks pretty sweet ! In the video 4 * 32x32 sprites are rotated through 64 steps at 30 FPS in software, it could be 60 FPS and more rotating objects if we were not doing the scaling at the same time but even blast processing has its limits ;-) Rotation at 30 FPS is far smoother than you typcially see in even in pre-rendered rotations anyhow ( a 64 frame 32x32 rotation is 32kb - not small ). Challenges were make it fast : very fast as this needs to work at pixel level, not double pixel like scaling. The megadrives packed pixel format (2 pixels per byte) makes that a little bit tricky . When I started the algorithm was 3x slower than now. Make it sensible : has to be usable in game , had to present a rom size reduction over pre-rendered animation. Make it flexible : so we can rotate frames in the background using up idle cycles (end of frame) and store those frames to vram for very heavy cpu scenes, so we can still have very smooth rotation with very heavy cpu demands still. Thanks to my team Carsten666 for the GFX and CYBERDEOUS - Crouzet Laurent for the marvelous tune. #SegaGenesis #SegaMegadrive #SGDK

SEGA GENESIS / MEGADRIVE Software Scaling + Rotation * Sega Megadrive can't scale backgrounds and rotate sprites in software at the same time ?? - hold my beer !! After Scaling I've been tinkering with Rotating sprites in software and I think it looks pretty sweet ! In the video 4 * 32x32 sprites are rotated through 64 steps at 30 FPS in software, it could be 60 FPS and more rotating objects if we were not doing the scaling at the same time but even blast processing has its limits ;-) Rotation at 30 FPS is far smoother than you typcially see in even in pre-rendered rotations anyhow ( a 64 frame 32x32 rotation is 32kb - not small ). Challenges were make it fast : very fast as this needs to work at pixel level, not double pixel like scaling. The megadrives packed pixel format (2 pixels per byte) makes that a little bit tricky . When I started the algorithm was 3x slower than now. Make it sensible : has to be usable in game , had to present a rom size reduction over pre-rendered animation. Make it flexible : so we can rotate frames in the background using up idle cycles (end of frame) and store those frames to vram for very heavy cpu scenes, so we can still have very smooth rotation with very heavy cpu demands still. Thanks to my team Carsten666 for the GFX and CYBERDEOUS - Crouzet Laurent for the marvelous tune. #SegaGenesis #SegaMegadrive #SGDK

Shannon Birt

19,405 views • 1 year ago

*** SOTA RETROCON S.O.T.A UPDATE *** Whilst the Versao LTDA team is busy at Retrocon showing off our latest Sega Genesis SOTA update, here is a small snippet of how the game is progressing. This video has 3 parts, our menu screen, rain - wind sub section of level 1, then the boss. Everything is still wip including my gameplay skill lol ( and i thought the controller would help .. ) Some challenges overcome : The Menu screen uses shadow and highlight transparency modes in two ways, the background mode for the light rays and then the sprite mode for the mist - it has a nice overlapping effect too, due to using the forground plane for the light rays (s & h background mode) the entire forground is made up of sprites - all the words are sprites . SaviorMarks sent me a screenshot of an issue with boss leftover Mist sprites affecting the menu screen and I thought that looks really cool - lets do that haha . Sometimes bugs are keepers !! The rain section uses more than 80 sprites, a sprite multiplexor handles the rain whilst normal non plexed sprites make up the moon / clouds in the far background , the lamp posts and lamp light in the mid forground and Fences in the front forground . Without the multiplexor there was too much drop out on the rain at times. The rain is still blinked in alternating X positions due to the pixels per line limit , but it gives a great result still. The lamp lights use Shaded Active Dither as S&H here would not overlap the enemies / player . The Boss was a challenge with its size and full frame updates, up to 650 tiles are changed per animation frame into vram. Custom Dual priority DMA routines and extended DMA timings are used (still NTSC 224 pixels tall screen size but most of the vblank was used for updating tiles ) . These methods were used to update the bosses dual display buffers. I needed to have dual priority DMA buffers as the player / waterfall etc had to update their frames whilst the boss is constantly streaming tiles. There are also S&H transparent Mist sprites used for the boss sequence. It seems if you want everything to break at once target a demo for a retrocon event haha, we had lots of issues mainly with vram getting stomped and as all animating sprites need to be DMA streamed to fit into VRAM as the forgrounds and backgrounds take up a lot of tiles. Some new tools which show the VRAM allocation for the sprite engine on a frame by frame basis helped and a self defragging VRAM system helped quite a bit also. Thankfully things are in a good state now apart from a couple of small bugs that persist. Thanks to SaviorMarks and @MichelinFabio for putting up with and testing all the bugged updates haha !! #SegaGenesis #SGDK @MichelinFabio SaviorMarks #VersaoLTDA

* SOTA RETROCON S.O.T.A UPDATE * Whilst the Versao LTDA team is busy at Retrocon showing off our latest Sega Genesis SOTA update, here is a small snippet of how the game is progressing. This video has 3 parts, our menu screen, rain - wind sub section of level 1, then the boss. Everything is still wip including my gameplay skill lol ( and i thought the controller would help .. ) Some challenges overcome : The Menu screen uses shadow and highlight transparency modes in two ways, the background mode for the light rays and then the sprite mode for the mist - it has a nice overlapping effect too, due to using the forground plane for the light rays (s & h background mode) the entire forground is made up of sprites - all the words are sprites . SaviorMarks sent me a screenshot of an issue with boss leftover Mist sprites affecting the menu screen and I thought that looks really cool - lets do that haha . Sometimes bugs are keepers !! The rain section uses more than 80 sprites, a sprite multiplexor handles the rain whilst normal non plexed sprites make up the moon / clouds in the far background , the lamp posts and lamp light in the mid forground and Fences in the front forground . Without the multiplexor there was too much drop out on the rain at times. The rain is still blinked in alternating X positions due to the pixels per line limit , but it gives a great result still. The lamp lights use Shaded Active Dither as S&H here would not overlap the enemies / player . The Boss was a challenge with its size and full frame updates, up to 650 tiles are changed per animation frame into vram. Custom Dual priority DMA routines and extended DMA timings are used (still NTSC 224 pixels tall screen size but most of the vblank was used for updating tiles ) . These methods were used to update the bosses dual display buffers. I needed to have dual priority DMA buffers as the player / waterfall etc had to update their frames whilst the boss is constantly streaming tiles. There are also S&H transparent Mist sprites used for the boss sequence. It seems if you want everything to break at once target a demo for a retrocon event haha, we had lots of issues mainly with vram getting stomped and as all animating sprites need to be DMA streamed to fit into VRAM as the forgrounds and backgrounds take up a lot of tiles. Some new tools which show the VRAM allocation for the sprite engine on a frame by frame basis helped and a self defragging VRAM system helped quite a bit also. Thankfully things are in a good state now apart from a couple of small bugs that persist. Thanks to SaviorMarks and @MichelinFabio for putting up with and testing all the bugged updates haha !! #SegaGenesis #SGDK @MichelinFabio SaviorMarks #VersaoLTDA

Shannon Birt

10,319 views • 1 year ago

*** Parodius Demo Update *** After seeing my good friend Pyron amazing Parodius artwork , I could not let that go to waste. Its a crying shame Konami's shooters did not make it to MD at the time , time to rectify that (in time). The video shows some of the progress so far. Stage 1 scrolling using the streaming scroller from lufthoheit to automatically manage the tile management for the scrolling rather than using different sets etc. Its great when I can grab bits of code and apply them to new projects, it speeds things up !! Lufthoheits new stage is coming along well also and has its first enemies in , hopefully show something of that soon. The VRAM view is to the right , we will have plenty of vram left for objects without resorting to much manual management it seems. ~ 1/2 vram left. It looks like the biggest challenge for this level is the Cat Ship mid boss - the end boss seems easier in comparison for a few reasons. I've analysed the way it was done on PCE and SNES and will come up with the best option for MD. More to come on that soon. At present we will target mainly assembly , so performance won't be an issue . I'm not sure we need a sprite multiplexor for > 80 sprites , but we will use one anyway just to not have regrets/changes later on and for the Hint color effects the multiplexor can do also. We have an A level musician volunteering also for those concerned about the audio side of things - it wont dissapoint I'm sure. As this is now my 3rd / 4th project it will be done as time permits so no gaurantees on timelines sorry - we are all hoping to do well by the community however. #SGDK #Konami #Parodius #MegaDrive #SegaGenesis

* Parodius Demo Update * After seeing my good friend Pyron amazing Parodius artwork , I could not let that go to waste. Its a crying shame Konami's shooters did not make it to MD at the time , time to rectify that (in time). The video shows some of the progress so far. Stage 1 scrolling using the streaming scroller from lufthoheit to automatically manage the tile management for the scrolling rather than using different sets etc. Its great when I can grab bits of code and apply them to new projects, it speeds things up !! Lufthoheits new stage is coming along well also and has its first enemies in , hopefully show something of that soon. The VRAM view is to the right , we will have plenty of vram left for objects without resorting to much manual management it seems. ~ 1/2 vram left. It looks like the biggest challenge for this level is the Cat Ship mid boss - the end boss seems easier in comparison for a few reasons. I've analysed the way it was done on PCE and SNES and will come up with the best option for MD. More to come on that soon. At present we will target mainly assembly , so performance won't be an issue . I'm not sure we need a sprite multiplexor for > 80 sprites , but we will use one anyway just to not have regrets/changes later on and for the Hint color effects the multiplexor can do also. We have an A level musician volunteering also for those concerned about the audio side of things - it wont dissapoint I'm sure. As this is now my 3rd / 4th project it will be done as time permits so no gaurantees on timelines sorry - we are all hoping to do well by the community however. #SGDK #Konami #Parodius #MegaDrive #SegaGenesis

Shannon Birt

12,526 views • 1 year ago

The McAlberts have desperately tried to rewrite history by claiming that the crowds outside supporting Karen Read were violent, unruly, and threatening. They claim in their lawsuit that supporters shouted at them, calling them murderers as they entered the court DURING the trial. This never happened, as there was a strictly enforced buffer zone, and all of the witnesses came into the courthouse heavily protected by police. But even before there was a buffer zone this is typically what Jen McCabe went through on her way into court with the O'Keefe family - silence.

The McAlberts have desperately tried to rewrite history by claiming that the crowds outside supporting Karen Read were violent, unruly, and threatening. They claim in their lawsuit that supporters shouted at them, calling them murderers as they entered the court DURING the trial. This never happened, as there was a strictly enforced buffer zone, and all of the witnesses came into the courthouse heavily protected by police. But even before there was a buffer zone this is typically what Jen McCabe went through on her way into court with the O'Keefe family - silence.

Aidan Kearney

36,451 views • 4 months ago