diff options
Diffstat (limited to 'GPU2D.cpp')
| -rw-r--r-- | GPU2D.cpp | 182 |
1 files changed, 175 insertions, 7 deletions
@@ -17,9 +17,9 @@ */ #include <stdio.h> +#include <string.h> #include "NDS.h" #include "GPU.h" -#include "GPU2D.h" GPU2D::GPU2D(u32 num) @@ -33,7 +33,8 @@ GPU2D::~GPU2D() void GPU2D::Reset() { - // + DispCnt = 0; + memset(BGCnt, 0, 4*2); } void GPU2D::SetFramebuffer(u16* buf) @@ -47,21 +48,31 @@ void GPU2D::SetFramebuffer(u16* buf) u8 GPU2D::Read8(u32 addr) { printf("!! GPU2D READ8 %08X\n", addr); + return 0; } u16 GPU2D::Read16(u32 addr) { switch (addr & 0x00000FFF) { - // + case 0x000: return DispCnt&0xFFFF; + case 0x002: return DispCnt>>16; + + case 0x008: return BGCnt[0]; + case 0x00A: return BGCnt[1]; + case 0x00C: return BGCnt[2]; + case 0x00E: return BGCnt[3]; } + + printf("unknown GPU read16 %08X\n", addr); + return 0; } u32 GPU2D::Read32(u32 addr) { switch (addr & 0x00000FFF) { - // + case 0x000: return DispCnt; } return Read16(addr) | (Read16(addr+2) << 16); @@ -76,15 +87,29 @@ void GPU2D::Write16(u32 addr, u16 val) { switch (addr & 0x00000FFF) { - // + case 0x000: + DispCnt = (DispCnt & 0xFFFF0000) | val; + return; + case 0x002: + DispCnt = (DispCnt & 0x0000FFFF) | (val << 16); + return; + + case 0x008: BGCnt[0] = val; return; + case 0x00A: BGCnt[1] = val; return; + case 0x00C: BGCnt[2] = val; return; + case 0x00E: BGCnt[3] = val; return; } + + printf("unknown GPU write16 %08X %04X\n", addr, val); } void GPU2D::Write32(u32 addr, u32 val) { switch (addr & 0x00000FFF) { - // + case 0x000: + DispCnt = val; + return; } Write16(addr, val&0xFFFF); @@ -94,5 +119,148 @@ void GPU2D::Write32(u32 addr, u32 val) void GPU2D::DrawScanline(u32 line) { - // + u16* dst = &Framebuffer[256*line]; + + u32 dispmode = DispCnt >> 16; + dispmode &= (Num ? 0x1 : 0x3); + + switch (dispmode) + { + case 0: // screen off + { + for (int i = 0; i < 256>>1; i++) + ((u32*)dst)[i] = 0x7FFF7FFF; + } + break; + + case 1: // regular display + { + DrawScanline_Mode1(line, dst); + } + break; + + case 2: // VRAM display + { + u32* vram = (u32*)GPU::VRAM[(DispCnt >> 18) & 0x3]; + vram = &vram[line << 7]; + + for (int i = 0; i < 256>>1; i++) + ((u32*)dst)[i] = vram[i]; + } + break; + + case 3: // FIFO display + { + // uh, is there even anything that uses this? + } + break; + } +} + +void GPU2D::DrawScanline_Mode1(u32 line, u16* dst) +{ + for (int i = 0; i < 256>>1; i++) + ((u32*)dst)[i] = 0; // TODO: backdrop + + switch (DispCnt & 0x7) + { + case 0: + for (int i = 3; i >= 0; i--) + { + // TODO other BGs + if ((BGCnt[0] & 0x3) == i) + { + DrawBG_Text_4bpp(line, dst, 0); + // todo: sprites + } + } + break; + } +} + +// char 06218000 +// screen 06208000 +void GPU2D::DrawBG_Text_4bpp(u32 line, u16* dst, u32 bgnum) +{ + u16 bgcnt = BGCnt[bgnum]; + + u8* tileset; + u16* tilemap; + u16* pal; + + // TODO scroll + u16 xoff = 0; + u16 yoff = line; + + u32 widexmask = (bgcnt & 0x4000) ? 0x100 : 0; + //u32 ymask = (bgcnt & 0x8000) ? 0x1FF : 0xFF; + + if (Num) + { + tileset = (u8*)GPU::VRAM_BBG[((bgcnt & 0x000C) >> 2)]; + tilemap = (u16*)GPU::VRAM_BBG[((bgcnt & 0x1800) >> 11)]; + tilemap += ((bgcnt & 0x0700) << 2); + + pal = (u16*)&GPU::Palette[0x400]; + } + else + { + tileset = (u8*)GPU::VRAM_ABG[((DispCnt & 0x07000000) >> 22) + ((bgcnt & 0x003C) >> 2)]; + tilemap = (u16*)GPU::VRAM_ABG[((DispCnt & 0x38000000) >> 27) + ((bgcnt & 0x1800) >> 11)]; + tilemap += ((bgcnt & 0x0700) << 2); + + pal = (u16*)&GPU::Palette[0]; + } + + // adjust Y position in tilemap + if (bgcnt & 0x8000) + { + tilemap += ((yoff & 0x1F8) << 2); + if (bgcnt & 0x4000) + tilemap += ((yoff & 0x100) << 2); + } + else + tilemap += ((yoff & 0xF8) << 2); + + u16 curtile; + u16* curpal; + u8* pixels; + + // preload shit as needed + if (xoff & 0x7) + { + // load a new tile + curtile = tilemap[((xoff & 0xFF) >> 3) + ((xoff & widexmask) << 2)]; + curpal = pal + ((curtile & 0xF000) >> 8); + pixels = tileset + ((curtile & 0x01FF) << 5) + ((yoff & 0x7) << 2); + pixels += ((xoff & 0x7) >> 1); + } + + for (int i = 0; i < 256; i++) + { + if (!(xoff & 0x7)) + { + // load a new tile + curtile = tilemap[((xoff & 0xFF) >> 3) + ((xoff & widexmask) << 2)]; + curpal = pal + ((curtile & 0xF000) >> 8); + pixels = tileset + ((curtile & 0x01FF) << 5) + ((yoff & 0x7) << 2); + } + + // draw pixel + u8 color; + if (xoff & 0x1) + { + color = *pixels >> 4; + pixels++; + } + else + { + color = *pixels & 0x0F; + } + //color = (i >> 4) + ((line >> 4) << 4); + //if (Num) color = 0; + dst[i] = curpal[color]; + + xoff++; + } } |