ref: bf35146ea4e3278487bb3ed655f182a8a0801c5c
dir: /snes/ppu.c/
#include <stdio.h> #include <stdlib.h> #include <string.h> #include <stdint.h> #include <stdbool.h> #include <stddef.h> #include <assert.h> #include "ppu.h" #include "../types.h" static const uint8 kSpriteSizes[8][2] = { {8, 16}, {8, 32}, {8, 64}, {16, 32}, {16, 64}, {32, 64}, {16, 32}, {16, 32} }; static void ppu_handlePixel(Ppu* ppu, int x, int y); static int ppu_getPixel(Ppu* ppu, int x, int y, bool sub, int* r, int* g, int* b); static int ppu_getPixelForBgLayer(Ppu *ppu, int x, int y, int layer, bool priority); static void ppu_calculateMode7Starts(Ppu* ppu, int y); static int ppu_getPixelForMode7(Ppu* ppu, int x, int layer, bool priority); static bool ppu_getWindowState(Ppu* ppu, int layer, int x); static bool ppu_evaluateSprites(Ppu* ppu, int line); static void PpuDrawWholeLine(Ppu *ppu, uint y); #define IS_SCREEN_ENABLED(ppu, sub, layer) (ppu->screenEnabled[sub] & (1 << layer)) #define IS_SCREEN_WINDOWED(ppu, sub, layer) (ppu->screenWindowed[sub] & (1 << layer)) #define IS_MOSAIC_ENABLED(ppu, layer) ((ppu->mosaicEnabled & (1 << layer))) #define GET_WINDOW_FLAGS(ppu, layer) (ppu->windowsel >> (layer * 4)) enum { kWindow1Inversed = 1, kWindow1Enabled = 2, kWindow2Inversed = 4, kWindow2Enabled = 8, }; Ppu* ppu_init() { Ppu* ppu = (Ppu * )malloc(sizeof(Ppu)); ppu->extraLeftRight = kPpuExtraLeftRight; return ppu; } void ppu_free(Ppu* ppu) { free(ppu); } void ppu_reset(Ppu* ppu) { memset(ppu->vram, 0, sizeof(ppu->vram)); ppu->lastBrightnessMult = 0xff; ppu->lastMosaicModulo = 0xff; ppu->extraLeftCur = 0; ppu->extraRightCur = 0; ppu->extraBottomCur = 0; ppu->vramPointer = 0; ppu->vramIncrementOnHigh = false; ppu->vramIncrement = 1; memset(ppu->cgram, 0, sizeof(ppu->cgram)); ppu->cgramPointer = 0; ppu->cgramSecondWrite = false; ppu->cgramBuffer = 0; memset(ppu->oam, 0, sizeof(ppu->oam)); ppu->oamAdr = 0; ppu->oamSecondWrite = false; ppu->oamBuffer = 0; ppu->objTileAdr1 = 0x4000; ppu->objTileAdr2 = 0x5000; ppu->objSize = 0; memset(&ppu->objBuffer, 0, sizeof(ppu->objBuffer)); for(int i = 0; i < 4; i++) { ppu->bgLayer[i].hScroll = 0; ppu->bgLayer[i].vScroll = 0; ppu->bgLayer[i].tilemapWider = false; ppu->bgLayer[i].tilemapHigher = false; ppu->bgLayer[i].tilemapAdr = 0; ppu->bgLayer[i].tileAdr = 0; } ppu->scrollPrev = 0; ppu->scrollPrev2 = 0; ppu->mosaicSize = 1; ppu->screenEnabled[0] = ppu->screenEnabled[1] = 0; ppu->screenWindowed[0] = ppu->screenWindowed[1] = 0; memset(ppu->m7matrix, 0, sizeof(ppu->m7matrix)); ppu->m7prev = 0; ppu->m7largeField = true; ppu->m7charFill = false; ppu->m7xFlip = false; ppu->m7yFlip = false; ppu->m7extBg_always_zero = false; ppu->m7startX = 0; ppu->m7startY = 0; ppu->windowsel = 0; ppu->window1left = 0; ppu->window1right = 0; ppu->window2left = 0; ppu->window2right = 0; ppu->clipMode = 0; ppu->preventMathMode = 0; ppu->addSubscreen = false; ppu->subtractColor = false; ppu->halfColor = false; ppu->mathEnabled = 0; ppu->fixedColorR = 0; ppu->fixedColorG = 0; ppu->fixedColorB = 0; ppu->forcedBlank = true; ppu->brightness = 0; ppu->mode = 0; } void ppu_saveload(Ppu *ppu, SaveLoadFunc *func, void *ctx) { uint8 tmp[556] = { 0 }; func(ctx, &ppu->vram, 0x8000 * 2); func(ctx, tmp, 10); func(ctx, &ppu->cgram, 512); func(ctx, tmp, 556); func(ctx, tmp, 520); for (int i = 0; i < 4; i++) { func(ctx, tmp, 4); func(ctx, &ppu->bgLayer[i].tilemapWider, 4); func(ctx, tmp, 4); } func(ctx, tmp, 123); } int PpuGetCurrentRenderScale(Ppu *ppu, uint32_t render_flags) { bool hq = ppu->mode == 7 && !ppu->forcedBlank && (render_flags & (kPpuRenderFlags_4x4Mode7 | kPpuRenderFlags_NewRenderer)) == (kPpuRenderFlags_4x4Mode7 | kPpuRenderFlags_NewRenderer); return hq ? 4 : 1; } void PpuBeginDrawing(Ppu *ppu, uint8_t *pixels, size_t pitch, uint32_t render_flags) { ppu->renderFlags = render_flags; ppu->renderPitch = (uint)pitch; ppu->renderBuffer = pixels; // Cache the brightness computation if (ppu->brightness != ppu->lastBrightnessMult) { uint8_t ppu_brightness = ppu->brightness; ppu->lastBrightnessMult = ppu_brightness; for (int i = 0; i < 32; i++) ppu->brightnessMultHalf[i * 2] = ppu->brightnessMultHalf[i * 2 + 1] = ppu->brightnessMult[i] = ((i << 3) | (i >> 2)) * ppu_brightness / 15; // Store 31 extra entries to remove the need for clamping to 31. memset(&ppu->brightnessMult[32], ppu->brightnessMult[31], 31); } if (PpuGetCurrentRenderScale(ppu, ppu->renderFlags) == 4) { for (int i = 0; i < 256; i++) { uint32 color = ppu->cgram[i]; ppu->colorMapRgb[i] = ppu->brightnessMult[color & 0x1f] << 16 | ppu->brightnessMult[(color >> 5) & 0x1f] << 8 | ppu->brightnessMult[(color >> 10) & 0x1f]; } } } static inline void ClearBackdrop(PpuPixelPrioBufs *buf) { for (size_t i = 0; i != countof(buf->data); i += 4) *(uint64*)&buf->data[i] = 0x0500050005000500; } void ppu_runLine(Ppu *ppu, int line) { if(line != 0) { if (ppu->mosaicSize != ppu->lastMosaicModulo) { int mod = ppu->mosaicSize; ppu->lastMosaicModulo = mod; for (int i = 0, j = 0; i < countof(ppu->mosaicModulo); i++) { ppu->mosaicModulo[i] = i - j; j = (j + 1 == mod ? 0 : j + 1); } } // evaluate sprites ClearBackdrop(&ppu->objBuffer); ppu->lineHasSprites = !ppu->forcedBlank && ppu_evaluateSprites(ppu, line - 1); // outside of visible range? if (line >= 225 + ppu->extraBottomCur) { memset(&ppu->renderBuffer[(line - 1) * ppu->renderPitch], 0, sizeof(uint32) * (256 + ppu->extraLeftRight * 2)); return; } if (ppu->renderFlags & kPpuRenderFlags_NewRenderer) { PpuDrawWholeLine(ppu, line); } else { if (ppu->mode == 7) ppu_calculateMode7Starts(ppu, line); for (int x = 0; x < 256; x++) ppu_handlePixel(ppu, x, line); uint8 *dst = ppu->renderBuffer + ((line - 1) * ppu->renderPitch); if (ppu->extraLeftRight != 0) { memset(dst, 0, sizeof(uint32) * ppu->extraLeftRight); memset(dst + sizeof(uint32) * (256 + ppu->extraLeftRight), 0, sizeof(uint32) * ppu->extraLeftRight); } } } } typedef struct PpuWindows { int16 edges[6]; uint8 nr; uint8 bits; } PpuWindows; static void PpuWindows_Clear(PpuWindows *win, Ppu *ppu, uint layer) { win->edges[0] = -(layer != 2 ? ppu->extraLeftCur : 0); win->edges[1] = 256 + (layer != 2 ? ppu->extraRightCur : 0); win->nr = 1; win->bits = 0; } static void PpuWindows_Calc(PpuWindows *win, Ppu *ppu, uint layer) { // Evaluate which spans to render based on the window settings. // There are at most 5 windows. // Algorithm from Snes9x uint32 winflags = GET_WINDOW_FLAGS(ppu, layer); uint nr = 1; int window_right = 256 + (layer != 2 ? ppu->extraRightCur : 0); win->edges[0] = - (layer != 2 ? ppu->extraLeftCur : 0); win->edges[1] = window_right; uint i, j; int t; bool w1_ena = (winflags & kWindow1Enabled) && ppu->window1left <= ppu->window1right; if (w1_ena) { if (ppu->window1left > win->edges[0]) { win->edges[nr] = ppu->window1left; win->edges[++nr] = window_right; } if (ppu->window1right + 1 < window_right) { win->edges[nr] = ppu->window1right + 1; win->edges[++nr] = window_right; } } bool w2_ena = (winflags & kWindow2Enabled) && ppu->window2left <= ppu->window2right; if (w2_ena) { for (i = 0; i <= nr && (t = ppu->window2left) != win->edges[i]; i++) { if (t < win->edges[i]) { for (j = nr++; j >= i; j--) win->edges[j + 1] = win->edges[j]; win->edges[i] = t; break; } } for (; i <= nr && (t = ppu->window2right + 1) != win->edges[i]; i++) { if (t < win->edges[i]) { for (j = nr++; j >= i; j--) win->edges[j + 1] = win->edges[j]; win->edges[i] = t; break; } } } win->nr = nr; // get a bitmap of how regions map to windows uint8 w1_bits = 0, w2_bits = 0; if (w1_ena) { for (i = 0; win->edges[i] != ppu->window1left; i++); for (j = i; win->edges[j] != ppu->window1right + 1; j++); w1_bits = ((1 << (j - i)) - 1) << i; } if ((winflags & (kWindow1Enabled | kWindow1Inversed)) == (kWindow1Enabled | kWindow1Inversed)) w1_bits = ~w1_bits; if (w2_ena) { for (i = 0; win->edges[i] != ppu->window2left; i++); for (j = i; win->edges[j] != ppu->window2right + 1; j++); w2_bits = ((1 << (j - i)) - 1) << i; } if ((winflags & (kWindow2Enabled | kWindow2Inversed)) == (kWindow2Enabled | kWindow2Inversed)) w2_bits = ~w2_bits; win->bits = w1_bits | w2_bits; } // Draw a whole line of a 4bpp background layer into bgBuffers static void PpuDrawBackground_4bpp(Ppu *ppu, uint y, bool sub, uint layer, PpuZbufType zhi, PpuZbufType zlo) { #define DO_PIXEL(i) do { \ pixel = (bits >> i) & 1 | (bits >> (7 + i)) & 2 | (bits >> (14 + i)) & 4 | (bits >> (21 + i)) & 8; \ if ((bits & (0x01010101 << i)) && z > dstz[i]) dstz[i] = z + pixel; } while (0) #define DO_PIXEL_HFLIP(i) do { \ pixel = (bits >> (7 - i)) & 1 | (bits >> (14 - i)) & 2 | (bits >> (21 - i)) & 4 | (bits >> (28 - i)) & 8; \ if ((bits & (0x80808080 >> i)) && z > dstz[i]) dstz[i] = z + pixel; } while (0) #define READ_BITS(ta, tile) (addr = &ppu->vram[((ta) + (tile) * 16) & 0x7fff], addr[0] | addr[8] << 16) enum { kPaletteShift = 6 }; if (!IS_SCREEN_ENABLED(ppu, sub, layer)) return; // layer is completely hidden PpuWindows win; IS_SCREEN_WINDOWED(ppu, sub, layer) ? PpuWindows_Calc(&win, ppu, layer) : PpuWindows_Clear(&win, ppu, layer); BgLayer *bglayer = &ppu->bgLayer[layer]; y += bglayer->vScroll; int sc_offs = bglayer->tilemapAdr + (((y >> 3) & 0x1f) << 5); if ((y & 0x100) && bglayer->tilemapHigher) sc_offs += bglayer->tilemapWider ? 0x800 : 0x400; const uint16 *tps[2] = { &ppu->vram[sc_offs & 0x7fff], &ppu->vram[sc_offs + (bglayer->tilemapWider ? 0x400 : 0) & 0x7fff] }; int tileadr = ppu->bgLayer[layer].tileAdr, pixel; int tileadr1 = tileadr + 7 - (y & 0x7), tileadr0 = tileadr + (y & 0x7); const uint16 *addr; for (size_t windex = 0; windex < win.nr; windex++) { if (win.bits & (1 << windex)) continue; // layer is disabled for this window part uint x = win.edges[windex] + bglayer->hScroll; uint w = win.edges[windex + 1] - win.edges[windex]; PpuZbufType *dstz = ppu->bgBuffers[sub].data + win.edges[windex] + kPpuExtraLeftRight; const uint16 *tp = tps[x >> 8 & 1] + ((x >> 3) & 0x1f); const uint16 *tp_last = tps[x >> 8 & 1] + 31; const uint16 *tp_next = tps[(x >> 8 & 1) ^ 1]; #define NEXT_TP() if (tp != tp_last) tp += 1; else tp = tp_next, tp_next = tp_last - 31, tp_last = tp + 31; // Handle clipped pixels on left side if (x & 7) { int curw = IntMin(8 - (x & 7), w); w -= curw; uint32 tile = *tp; NEXT_TP(); int ta = (tile & 0x8000) ? tileadr1 : tileadr0; PpuZbufType z = (tile & 0x2000) ? zhi : zlo; uint32 bits = READ_BITS(ta, tile & 0x3ff); if (bits) { z += ((tile & 0x1c00) >> kPaletteShift); if (tile & 0x4000) { bits >>= (x & 7), x += curw; do DO_PIXEL(0); while (bits >>= 1, dstz++, --curw); } else { bits <<= (x & 7), x += curw; do DO_PIXEL_HFLIP(0); while (bits <<= 1, dstz++, --curw); } } else { dstz += curw; } } // Handle full tiles in the middle while (w >= 8) { uint32 tile = *tp; NEXT_TP(); int ta = (tile & 0x8000) ? tileadr1 : tileadr0; PpuZbufType z = (tile & 0x2000) ? zhi : zlo; uint32 bits = READ_BITS(ta, tile & 0x3ff); if (bits) { z += ((tile & 0x1c00) >> kPaletteShift); if (tile & 0x4000) { DO_PIXEL(0); DO_PIXEL(1); DO_PIXEL(2); DO_PIXEL(3); DO_PIXEL(4); DO_PIXEL(5); DO_PIXEL(6); DO_PIXEL(7); } else { DO_PIXEL_HFLIP(0); DO_PIXEL_HFLIP(1); DO_PIXEL_HFLIP(2); DO_PIXEL_HFLIP(3); DO_PIXEL_HFLIP(4); DO_PIXEL_HFLIP(5); DO_PIXEL_HFLIP(6); DO_PIXEL_HFLIP(7); } } dstz += 8, w -= 8; } // Handle remaining clipped part if (w) { uint32 tile = *tp; int ta = (tile & 0x8000) ? tileadr1 : tileadr0; PpuZbufType z = (tile & 0x2000) ? zhi : zlo; uint32 bits = READ_BITS(ta, tile & 0x3ff); if (bits) { z += ((tile & 0x1c00) >> kPaletteShift); if (tile & 0x4000) { do DO_PIXEL(0); while (bits >>= 1, dstz++, --w); } else { do DO_PIXEL_HFLIP(0); while (bits <<= 1, dstz++, --w); } } } } #undef READ_BITS #undef DO_PIXEL #undef DO_PIXEL_HFLIP } // Draw a whole line of a 2bpp background layer into bgBuffers static void PpuDrawBackground_2bpp(Ppu *ppu, uint y, bool sub, uint layer, PpuZbufType zhi, PpuZbufType zlo) { #define DO_PIXEL(i) do { \ pixel = (bits >> i) & 1 | (bits >> (7 + i)) & 2; \ if (pixel && z > dstz[i]) dstz[i] = z + pixel; } while (0) #define DO_PIXEL_HFLIP(i) do { \ pixel = (bits >> (7 - i)) & 1 | (bits >> (14 - i)) & 2; \ if (pixel && z > dstz[i]) dstz[i] = z + pixel; } while (0) #define READ_BITS(ta, tile) (addr = &ppu->vram[(ta) + (tile) * 8 & 0x7fff], addr[0]) enum { kPaletteShift = 8 }; if (!IS_SCREEN_ENABLED(ppu, sub, layer)) return; // layer is completely hidden PpuWindows win; IS_SCREEN_WINDOWED(ppu, sub, layer) ? PpuWindows_Calc(&win, ppu, layer) : PpuWindows_Clear(&win, ppu, layer); BgLayer *bglayer = &ppu->bgLayer[layer]; y += bglayer->vScroll; int sc_offs = bglayer->tilemapAdr + (((y >> 3) & 0x1f) << 5); if ((y & 0x100) && bglayer->tilemapHigher) sc_offs += bglayer->tilemapWider ? 0x800 : 0x400; const uint16 *tps[2] = { &ppu->vram[sc_offs & 0x7fff], &ppu->vram[sc_offs + (bglayer->tilemapWider ? 0x400 : 0) & 0x7fff] }; int tileadr = ppu->bgLayer[layer].tileAdr, pixel; int tileadr1 = tileadr + 7 - (y & 0x7), tileadr0 = tileadr + (y & 0x7); const uint16 *addr; for (size_t windex = 0; windex < win.nr; windex++) { if (win.bits & (1 << windex)) continue; // layer is disabled for this window part uint x = win.edges[windex] + bglayer->hScroll; uint w = win.edges[windex + 1] - win.edges[windex]; PpuZbufType *dstz = ppu->bgBuffers[sub].data + win.edges[windex] + kPpuExtraLeftRight; const uint16 *tp = tps[x >> 8 & 1] + ((x >> 3) & 0x1f); const uint16 *tp_last = tps[x >> 8 & 1] + 31; const uint16 *tp_next = tps[(x >> 8 & 1) ^ 1]; #define NEXT_TP() if (tp != tp_last) tp += 1; else tp = tp_next, tp_next = tp_last - 31, tp_last = tp + 31; // Handle clipped pixels on left side if (x & 7) { int curw = IntMin(8 - (x & 7), w); w -= curw; uint32 tile = *tp; NEXT_TP(); int ta = (tile & 0x8000) ? tileadr1 : tileadr0; PpuZbufType z = (tile & 0x2000) ? zhi : zlo; uint32 bits = READ_BITS(ta, tile & 0x3ff); if (bits) { z += ((tile & 0x1c00) >> kPaletteShift); if (tile & 0x4000) { bits >>= (x & 7), x += curw; do DO_PIXEL(0); while (bits >>= 1, dstz++, --curw); } else { bits <<= (x & 7), x += curw; do DO_PIXEL_HFLIP(0); while (bits <<= 1, dstz++, --curw); } } else { dstz += curw; } } // Handle full tiles in the middle while (w >= 8) { uint32 tile = *tp; NEXT_TP(); int ta = (tile & 0x8000) ? tileadr1 : tileadr0; PpuZbufType z = (tile & 0x2000) ? zhi : zlo; uint32 bits = READ_BITS(ta, tile & 0x3ff); if (bits) { z += ((tile & 0x1c00) >> kPaletteShift); if (tile & 0x4000) { DO_PIXEL(0); DO_PIXEL(1); DO_PIXEL(2); DO_PIXEL(3); DO_PIXEL(4); DO_PIXEL(5); DO_PIXEL(6); DO_PIXEL(7); } else { DO_PIXEL_HFLIP(0); DO_PIXEL_HFLIP(1); DO_PIXEL_HFLIP(2); DO_PIXEL_HFLIP(3); DO_PIXEL_HFLIP(4); DO_PIXEL_HFLIP(5); DO_PIXEL_HFLIP(6); DO_PIXEL_HFLIP(7); } } dstz += 8, w -= 8; } // Handle remaining clipped part if (w) { uint32 tile = *tp; int ta = (tile & 0x8000) ? tileadr1 : tileadr0; PpuZbufType z = (tile & 0x2000) ? zhi : zlo; uint32 bits = READ_BITS(ta, tile & 0x3ff); if (bits) { z += ((tile & 0x1c00) >> kPaletteShift); if (tile & 0x4000) { do DO_PIXEL(0); while (bits >>= 1, dstz++, --w); } else { do DO_PIXEL_HFLIP(0); while (bits <<= 1, dstz++, --w); } } } } #undef NEXT_TP #undef READ_BITS #undef DO_PIXEL #undef DO_PIXEL_HFLIP } // Draw a whole line of a 4bpp background layer into bgBuffers, with mosaic applied static void PpuDrawBackground_4bpp_mosaic(Ppu *ppu, uint y, bool sub, uint layer, PpuZbufType zhi, PpuZbufType zlo) { #define GET_PIXEL() pixel = (bits) & 1 | (bits >> 7) & 2 | (bits >> 14) & 4 | (bits >> 21) & 8 #define GET_PIXEL_HFLIP() pixel = (bits >> 7) & 1 | (bits >> 14) & 2 | (bits >> 21) & 4 | (bits >> 28) & 8 #define READ_BITS(ta, tile) (addr = &ppu->vram[((ta) + (tile) * 16) & 0x7fff], addr[0] | addr[8] << 16) enum { kPaletteShift = 6 }; if (!IS_SCREEN_ENABLED(ppu, sub, layer)) return; // layer is completely hidden PpuWindows win; IS_SCREEN_WINDOWED(ppu, sub, layer) ? PpuWindows_Calc(&win, ppu, layer) : PpuWindows_Clear(&win, ppu, layer); BgLayer *bglayer = &ppu->bgLayer[layer]; y = ppu->mosaicModulo[y] + bglayer->vScroll; int sc_offs = bglayer->tilemapAdr + (((y >> 3) & 0x1f) << 5); if ((y & 0x100) && bglayer->tilemapHigher) sc_offs += bglayer->tilemapWider ? 0x800 : 0x400; const uint16 *tps[2] = { &ppu->vram[sc_offs & 0x7fff], &ppu->vram[sc_offs + (bglayer->tilemapWider ? 0x400 : 0) & 0x7fff] }; int tileadr = ppu->bgLayer[layer].tileAdr, pixel; int tileadr1 = tileadr + 7 - (y & 0x7), tileadr0 = tileadr + (y & 0x7); const uint16 *addr; for (size_t windex = 0; windex < win.nr; windex++) { if (win.bits & (1 << windex)) continue; // layer is disabled for this window part int sx = win.edges[windex]; PpuZbufType *dstz = ppu->bgBuffers[sub].data + sx + kPpuExtraLeftRight; PpuZbufType *dstz_end = ppu->bgBuffers[sub].data + win.edges[windex + 1] + kPpuExtraLeftRight; uint x = sx + bglayer->hScroll; const uint16 *tp = tps[x >> 8 & 1] + ((x >> 3) & 0x1f); const uint16 *tp_last = tps[x >> 8 & 1] + 31, *tp_next = tps[(x >> 8 & 1) ^ 1]; x &= 7; int w = ppu->mosaicSize - (sx - ppu->mosaicModulo[sx]); do { w = IntMin(w, dstz_end - dstz); uint32 tile = *tp; int ta = (tile & 0x8000) ? tileadr1 : tileadr0; PpuZbufType z = (tile & 0x2000) ? zhi : zlo; uint32 bits = READ_BITS(ta, tile & 0x3ff); if (tile & 0x4000) bits >>= x, GET_PIXEL(); else bits <<= x, GET_PIXEL_HFLIP(); if (pixel) { pixel += (tile & 0x1c00) >> kPaletteShift; int i = 0; do { if (z > dstz[i]) dstz[i] = pixel + z; } while (++i != w); } dstz += w, x += w; for (; x >= 8; x -= 8) tp = (tp != tp_last) ? tp + 1 : tp_next; w = ppu->mosaicSize; } while (dstz_end - dstz != 0); } #undef READ_BITS #undef GET_PIXEL #undef GET_PIXEL_HFLIP } // Draw a whole line of a 2bpp background layer into bgBuffers, with mosaic applied static void PpuDrawBackground_2bpp_mosaic(Ppu *ppu, int y, bool sub, uint layer, PpuZbufType zhi, PpuZbufType zlo) { #define GET_PIXEL() pixel = (bits) & 1 | (bits >> 7) & 2 #define GET_PIXEL_HFLIP() pixel = (bits >> 7) & 1 | (bits >> 14) & 2 #define READ_BITS(ta, tile) (addr = &ppu->vram[((ta) + (tile) * 8) & 0x7fff], addr[0]) enum { kPaletteShift = 8 }; if (!IS_SCREEN_ENABLED(ppu, sub, layer)) return; // layer is completely hidden PpuWindows win; IS_SCREEN_WINDOWED(ppu, sub, layer) ? PpuWindows_Calc(&win, ppu, layer) : PpuWindows_Clear(&win, ppu, layer); BgLayer *bglayer = &ppu->bgLayer[layer]; y = ppu->mosaicModulo[y] + bglayer->vScroll; int sc_offs = bglayer->tilemapAdr + (((y >> 3) & 0x1f) << 5); if ((y & 0x100) && bglayer->tilemapHigher) sc_offs += bglayer->tilemapWider ? 0x800 : 0x400; const uint16 *tps[2] = { &ppu->vram[sc_offs & 0x7fff], &ppu->vram[sc_offs + (bglayer->tilemapWider ? 0x400 : 0) & 0x7fff] }; int tileadr = ppu->bgLayer[layer].tileAdr, pixel; int tileadr1 = tileadr + 7 - (y & 0x7), tileadr0 = tileadr + (y & 0x7); const uint16 *addr; for (size_t windex = 0; windex < win.nr; windex++) { if (win.bits & (1 << windex)) continue; // layer is disabled for this window part int sx = win.edges[windex]; PpuZbufType *dstz = ppu->bgBuffers[sub].data + sx + kPpuExtraLeftRight; PpuZbufType *dstz_end = ppu->bgBuffers[sub].data + win.edges[windex + 1] + kPpuExtraLeftRight; uint x = sx + bglayer->hScroll; const uint16 *tp = tps[x >> 8 & 1] + ((x >> 3) & 0x1f); const uint16 *tp_last = tps[x >> 8 & 1] + 31, *tp_next = tps[(x >> 8 & 1) ^ 1]; x &= 7; int w = ppu->mosaicSize - (sx - ppu->mosaicModulo[sx]); do { w = IntMin(w, dstz_end - dstz); uint32 tile = *tp; int ta = (tile & 0x8000) ? tileadr1 : tileadr0; PpuZbufType z = (tile & 0x2000) ? zhi : zlo; uint32 bits = READ_BITS(ta, tile & 0x3ff); if (tile & 0x4000) bits >>= x, GET_PIXEL(); else bits <<= x, GET_PIXEL_HFLIP(); if (pixel) { pixel += (tile & 0x1c00) >> kPaletteShift; uint i = 0; do { if (z > dstz[i]) dstz[i] = pixel + z; } while (++i != w); } dstz += w, x += w; for (; x >= 8; x -= 8) tp = (tp != tp_last) ? tp + 1 : tp_next; w = ppu->mosaicSize; } while (dstz_end - dstz != 0); } #undef READ_BITS #undef GET_PIXEL #undef GET_PIXEL_HFLIP } // level6 should be set if it's from palette 0xc0 which means color math is not applied #define SPRITE_PRIO_TO_PRIO(prio, level6) (((prio) * 4 + 2) * 16 + 4 + (level6 ? 2 : 0)) #define SPRITE_PRIO_TO_PRIO_HI(prio) ((prio) * 4 + 2) static void PpuDrawSprites(Ppu *ppu, uint y, uint sub, bool clear_backdrop) { int layer = 4; if (!IS_SCREEN_ENABLED(ppu, sub, layer)) return; // layer is completely hidden PpuWindows win; IS_SCREEN_WINDOWED(ppu, sub, layer) ? PpuWindows_Calc(&win, ppu, layer) : PpuWindows_Clear(&win, ppu, layer); for (size_t windex = 0; windex < win.nr; windex++) { if (win.bits & (1 << windex)) continue; // layer is disabled for this window part int left = win.edges[windex]; int width = win.edges[windex + 1] - left; PpuZbufType *src = ppu->objBuffer.data + left + kPpuExtraLeftRight; PpuZbufType *dst = ppu->bgBuffers[sub].data + left + kPpuExtraLeftRight; if (clear_backdrop) { memcpy(dst, src, width * sizeof(uint16)); } else { do { if (src[0] > dst[0]) dst[0] = src[0]; } while (src++, dst++, --width); } } } // Assumes it's drawn on an empty backdrop static void PpuDrawBackground_mode7(Ppu *ppu, uint y, bool sub, PpuZbufType z) { int layer = 0; if (!IS_SCREEN_ENABLED(ppu, sub, layer)) return; // layer is completely hidden PpuWindows win; IS_SCREEN_WINDOWED(ppu, sub, layer) ? PpuWindows_Calc(&win, ppu, layer) : PpuWindows_Clear(&win, ppu, layer); // expand 13-bit values to signed values int hScroll = ((int16_t)(ppu->m7matrix[6] << 3)) >> 3; int vScroll = ((int16_t)(ppu->m7matrix[7] << 3)) >> 3; int xCenter = ((int16_t)(ppu->m7matrix[4] << 3)) >> 3; int yCenter = ((int16_t)(ppu->m7matrix[5] << 3)) >> 3; int clippedH = hScroll - xCenter; int clippedV = vScroll - yCenter; clippedH = (clippedH & 0x2000) ? (clippedH | ~1023) : (clippedH & 1023); clippedV = (clippedV & 0x2000) ? (clippedV | ~1023) : (clippedV & 1023); bool mosaic_enabled = IS_MOSAIC_ENABLED(ppu, 0); if (mosaic_enabled) y = ppu->mosaicModulo[y]; uint32 ry = ppu->m7yFlip ? 255 - y : y; uint32 m7startX = (ppu->m7matrix[0] * clippedH & ~63) + (ppu->m7matrix[1] * ry & ~63) + (ppu->m7matrix[1] * clippedV & ~63) + (xCenter << 8); uint32 m7startY = (ppu->m7matrix[2] * clippedH & ~63) + (ppu->m7matrix[3] * ry & ~63) + (ppu->m7matrix[3] * clippedV & ~63) + (yCenter << 8); for (size_t windex = 0; windex < win.nr; windex++) { if (win.bits & (1 << windex)) continue; // layer is disabled for this window part int x = win.edges[windex], x2 = win.edges[windex + 1], tile; PpuZbufType *dstz = ppu->bgBuffers[sub].data + x + kPpuExtraLeftRight; PpuZbufType *dstz_end = ppu->bgBuffers[sub].data + x2 + kPpuExtraLeftRight; uint32 rx = ppu->m7xFlip ? 255 - x : x; uint32 xpos = m7startX + ppu->m7matrix[0] * rx; uint32 ypos = m7startY + ppu->m7matrix[2] * rx; uint32 dx = ppu->m7xFlip ? -ppu->m7matrix[0] : ppu->m7matrix[0]; uint32 dy = ppu->m7xFlip ? -ppu->m7matrix[2] : ppu->m7matrix[2]; uint32 outside_value = ppu->m7largeField ? 0x3ffff : 0xffffffff; bool char_fill = ppu->m7charFill; if (mosaic_enabled) { int w = ppu->mosaicSize - (x - ppu->mosaicModulo[x]); do { w = IntMin(w, dstz_end - dstz); if ((uint32)(xpos | ypos) > outside_value) { if (!char_fill) continue; tile = 0; } else { tile = ppu->vram[(ypos >> 11 & 0x7f) * 128 + (xpos >> 11 & 0x7f)] & 0xff; } uint8 pixel = ppu->vram[tile * 64 + (ypos >> 8 & 7) * 8 + (xpos >> 8 & 7)] >> 8; if (pixel) { int i = 0; do dstz[i] = pixel + z; while (++i != w); } } while (xpos += dx * w, ypos += dy * w, dstz += w, w = ppu->mosaicSize, dstz_end - dstz != 0); } else { do { if ((uint32)(xpos | ypos) > outside_value) { if (!char_fill) continue; tile = 0; } else { tile = ppu->vram[(ypos >> 11 & 0x7f) * 128 + (xpos >> 11 & 0x7f)] & 0xff; } uint8 pixel = ppu->vram[tile * 64 + (ypos >> 8 & 7) * 8 + (xpos >> 8 & 7)] >> 8; if (pixel) dstz[0] = pixel + z; } while (xpos += dx, ypos += dy, ++dstz != dstz_end); } } } void PpuSetMode7PerspectiveCorrection(Ppu *ppu, int low, int high) { ppu->mode7PerspectiveLow = low ? 1.0f / low : 0.0f; ppu->mode7PerspectiveHigh = 1.0f / high; } void PpuSetExtraSideSpace(Ppu *ppu, int left, int right, int bottom) { ppu->extraLeftCur = UintMin(left, ppu->extraLeftRight); ppu->extraRightCur = UintMin(right, ppu->extraLeftRight); ppu->extraBottomCur = UintMin(bottom, 16); } static FORCEINLINE float FloatInterpolate(float x, float xmin, float xmax, float ymin, float ymax) { return ymin + (ymax - ymin) * (x - xmin) * (1.0f / (xmax - xmin)); } // Upsampled version of mode7 rendering. Draws everything in 4x the normal resolution. // Draws directly to the pixel buffer and bypasses any math, and supports only // a subset of the normal features (all that zelda needs) static void PpuDrawMode7Upsampled(Ppu *ppu, uint y) { // expand 13-bit values to signed values uint32 xCenter = ((int16_t)(ppu->m7matrix[4] << 3)) >> 3, yCenter = ((int16_t)(ppu->m7matrix[5] << 3)) >> 3; uint32 clippedH = (((int16_t)(ppu->m7matrix[6] << 3)) >> 3) - xCenter; uint32 clippedV = (((int16_t)(ppu->m7matrix[7] << 3)) >> 3) - yCenter; int32 m0v[4]; if (*(uint32*)&ppu->mode7PerspectiveLow == 0) { m0v[0] = m0v[1] = m0v[2] = m0v[3] = ppu->m7matrix[0] << 12; } else { static const float kInterpolateOffsets[4] = { -1, -1 + 0.25f, -1 + 0.5f, -1 + 0.75f }; for (int i = 0; i < 4; i++) m0v[i] = 4096.0f / FloatInterpolate((int)y + kInterpolateOffsets[i], 0, 223, ppu->mode7PerspectiveLow, ppu->mode7PerspectiveHigh); } size_t pitch = ppu->renderPitch; uint8 *render_buffer_ptr = &ppu->renderBuffer[(y - 1) * 4 * pitch]; uint8 *dst_start = render_buffer_ptr + (ppu->extraLeftRight - ppu->extraLeftCur) * 16; size_t draw_width = 256 + ppu->extraLeftCur + ppu->extraRightCur; uint8 *dst_curline = dst_start; uint32 m1 = ppu->m7matrix[1] << 12; // xpos increment per vert movement uint32 m2 = ppu->m7matrix[2] << 12; // ypos increment per horiz movement for (int j = 0; j < 4; j++) { uint32 m0 = m0v[j], m3 = m0; uint32 xpos = m0 * clippedH + m1 * (clippedV + y) + (xCenter << 20), xcur; uint32 ypos = m2 * clippedH + m3 * (clippedV + y) + (yCenter << 20), ycur; uint32 tile, pixel; xpos -= (m0 + m1) >> 1; ypos -= (m2 + m3) >> 1; xcur = (xpos << 2) + j * m1; ycur = (ypos << 2) + j * m3; xcur -= ppu->extraLeftCur * 4 * m0; ycur -= ppu->extraLeftCur * 4 * m2; uint8 *dst = dst_curline; uint8 *dst_end = dst_curline + draw_width * 16; #define DRAW_PIXEL(mode) \ tile = ppu->vram[(ycur >> 25 & 0x7f) * 128 + (xcur >> 25 & 0x7f)] & 0xff; \ pixel = ppu->vram[tile * 64 + (ycur >> 22 & 7) * 8 + (xcur >> 22 & 7)] >> 8; \ pixel = (xcur & 0x80000000) ? 0 : pixel; \ *(uint32*)dst = (mode ? (ppu->colorMapRgb[pixel] & 0xfefefe) >> 1 : ppu->colorMapRgb[pixel]); \ xcur += m0, ycur += m2, dst += 4; if (!ppu->halfColor) { do { DRAW_PIXEL(0); DRAW_PIXEL(0); DRAW_PIXEL(0); DRAW_PIXEL(0); } while (dst != dst_end); } else { do { DRAW_PIXEL(1); DRAW_PIXEL(1); DRAW_PIXEL(1); DRAW_PIXEL(1); } while (dst != dst_end); } #undef DRAW_PIXEL dst_curline += pitch; } if (ppu->lineHasSprites) { uint8 *dst = dst_start; PpuZbufType *pixels = ppu->objBuffer.data + (kPpuExtraLeftRight - ppu->extraLeftCur); for (size_t i = 0; i < draw_width; i++, dst += 16) { uint32 pixel = pixels[i] & 0xff; if (pixel) { uint32 color = ppu->colorMapRgb[pixel]; ((uint32 *)dst)[3] = ((uint32 *)dst)[2] = ((uint32 *)dst)[1] = ((uint32 *)dst)[0] = color; ((uint32 *)(dst + pitch * 1))[3] = ((uint32 *)(dst + pitch * 1))[2] = ((uint32 *)(dst + pitch * 1))[1] = ((uint32 *)(dst + pitch * 1))[0] = color; ((uint32 *)(dst + pitch * 2))[3] = ((uint32 *)(dst + pitch * 2))[2] = ((uint32 *)(dst + pitch * 2))[1] = ((uint32 *)(dst + pitch * 2))[0] = color; ((uint32 *)(dst + pitch * 3))[3] = ((uint32 *)(dst + pitch * 3))[2] = ((uint32 *)(dst + pitch * 3))[1] = ((uint32 *)(dst + pitch * 3))[0] = color; } } } if (ppu->extraLeftRight - ppu->extraLeftCur != 0) { size_t n = 4 * sizeof(uint32) * (ppu->extraLeftRight - ppu->extraLeftCur); for(int i = 0; i < 4; i++) memset(render_buffer_ptr + pitch * i, 0, n); } if (ppu->extraLeftRight - ppu->extraRightCur != 0) { size_t n = 4 * sizeof(uint32) * (ppu->extraLeftRight - ppu->extraRightCur); for (int i = 0; i < 4; i++) memset(render_buffer_ptr + pitch * i + (256 + ppu->extraLeftRight * 2 - (ppu->extraLeftRight - ppu->extraRightCur)) * 4 * sizeof(uint32), 0, n); } #undef DRAW_PIXEL } static void PpuDrawBackgrounds(Ppu *ppu, int y, bool sub) { // Top 4 bits contain the prio level, and bottom 4 bits the layer type. // SPRITE_PRIO_TO_PRIO can be used to convert from obj prio to this prio. // 15: BG3 tiles with priority 1 if bit 3 of $2105 is set // 14: Sprites with priority 3 (4 * sprite_prio + 2) // 12: BG1 tiles with priority 1 // 11: BG2 tiles with priority 1 // 10: Sprites with priority 2 (4 * sprite_prio + 2) // 8: BG1 tiles with priority 0 // 7: BG2 tiles with priority 0 // 6: Sprites with priority 1 (4 * sprite_prio + 2) // 3: BG3 tiles with priority 1 if bit 3 of $2105 is clear // 2: Sprites with priority 0 (4 * sprite_prio + 2) // 1: BG3 tiles with priority 0 // 0: backdrop if (ppu->mode == 1) { if (ppu->lineHasSprites) PpuDrawSprites(ppu, y, sub, true); if (IS_MOSAIC_ENABLED(ppu, 0)) PpuDrawBackground_4bpp_mosaic(ppu, y, sub, 0, 0xc000, 0x8000); else PpuDrawBackground_4bpp(ppu, y, sub, 0, 0xc000, 0x8000); if (IS_MOSAIC_ENABLED(ppu, 1)) PpuDrawBackground_4bpp_mosaic(ppu, y, sub, 1, 0xb100, 0x7100); else PpuDrawBackground_4bpp(ppu, y, sub, 1, 0xb100, 0x7100); if (IS_MOSAIC_ENABLED(ppu, 2)) PpuDrawBackground_2bpp_mosaic(ppu, y, sub, 2, 0xf200, 0x1200); else PpuDrawBackground_2bpp(ppu, y, sub, 2, 0xf200, 0x1200); } else { // mode 7 PpuDrawBackground_mode7(ppu, y, sub, 0xc000); if (ppu->lineHasSprites) PpuDrawSprites(ppu, y, sub, false); } } static NOINLINE void PpuDrawWholeLine(Ppu *ppu, uint y) { if (ppu->forcedBlank) { uint8 *dst = &ppu->renderBuffer[(y - 1) * ppu->renderPitch]; size_t n = sizeof(uint32) * (256 + ppu->extraLeftRight * 2); memset(dst, 0, n); return; } if (ppu->mode == 7 && (ppu->renderFlags & kPpuRenderFlags_4x4Mode7)) { PpuDrawMode7Upsampled(ppu, y); return; } // Default background is backdrop ClearBackdrop(&ppu->bgBuffers[0]); // Render main screen PpuDrawBackgrounds(ppu, y, false); // The 6:th bit is automatically zero, math is never applied to the first half of the sprites. uint32 math_enabled = ppu->mathEnabled; // Render also the subscreen? bool rendered_subscreen = false; if (ppu->preventMathMode != 3 && ppu->addSubscreen && math_enabled) { ClearBackdrop(&ppu->bgBuffers[1]); if (ppu->screenEnabled[1] != 0) { PpuDrawBackgrounds(ppu, y, true); rendered_subscreen = true; } } // Color window affects the drawing mode in each region PpuWindows cwin; PpuWindows_Calc(&cwin, ppu, 5); static const uint8 kCwBitsMod[8] = { 0x00, 0xff, 0xff, 0x00, 0xff, 0x00, 0xff, 0x00, }; uint32 cw_clip_math = ((cwin.bits & kCwBitsMod[ppu->clipMode]) ^ kCwBitsMod[ppu->clipMode + 4]) | ((cwin.bits & kCwBitsMod[ppu->preventMathMode]) ^ kCwBitsMod[ppu->preventMathMode + 4]) << 8; uint32 *dst = (uint32*)&ppu->renderBuffer[(y - 1) * ppu->renderPitch], *dst_org = dst; dst += (ppu->extraLeftRight - ppu->extraLeftCur); uint32 windex = 0; do { uint32 left = cwin.edges[windex] + kPpuExtraLeftRight, right = cwin.edges[windex + 1] + kPpuExtraLeftRight; // If clip is set, then zero out the rgb values from the main screen. uint32 clip_color_mask = (cw_clip_math & 1) ? 0x1f : 0; uint32 math_enabled_cur = (cw_clip_math & 0x100) ? math_enabled : 0; uint32 fixed_color = ppu->fixedColorR | ppu->fixedColorG << 5 | ppu->fixedColorB << 10; if (math_enabled_cur == 0 || fixed_color == 0 && !ppu->halfColor && !rendered_subscreen) { // Math is disabled (or has no effect), so can avoid the per-pixel maths check uint32 i = left; do { uint32 color = ppu->cgram[ppu->bgBuffers[0].data[i] & 0xff]; dst[0] = ppu->brightnessMult[color & clip_color_mask] << 16 | ppu->brightnessMult[(color >> 5) & clip_color_mask] << 8 | ppu->brightnessMult[(color >> 10) & clip_color_mask]; } while (dst++, ++i < right); } else { uint8 *half_color_map = ppu->halfColor ? ppu->brightnessMultHalf : ppu->brightnessMult; // Store this in locals math_enabled_cur |= ppu->addSubscreen << 8 | ppu->subtractColor << 9; // Need to check for each pixel whether to use math or not based on the main screen layer. uint32 i = left; do { uint32 color = ppu->cgram[ppu->bgBuffers[0].data[i] & 0xff], color2; uint8 main_layer = (ppu->bgBuffers[0].data[i] >> 8) & 0xf; uint32 r = color & clip_color_mask; uint32 g = (color >> 5) & clip_color_mask; uint32 b = (color >> 10) & clip_color_mask; uint8 *color_map = ppu->brightnessMult; if (math_enabled_cur & (1 << main_layer)) { if (math_enabled_cur & 0x100) { // addSubscreen ? if ((ppu->bgBuffers[1].data[i] & 0xff) != 0) color2 = ppu->cgram[ppu->bgBuffers[1].data[i] & 0xff], color_map = half_color_map; else // Don't halve if ppu->addSubscreen && backdrop color2 = fixed_color; } else { color2 = fixed_color, color_map = half_color_map; } uint32 r2 = (color2 & 0x1f), g2 = ((color2 >> 5) & 0x1f), b2 = ((color2 >> 10) & 0x1f); if (math_enabled_cur & 0x200) { // subtractColor? r = (r >= r2) ? r - r2 : 0; g = (g >= g2) ? g - g2 : 0; b = (b >= b2) ? b - b2 : 0; } else { r += r2; g += g2; b += b2; } } dst[0] = color_map[b] | color_map[g] << 8 | color_map[r] << 16; } while (dst++, ++i < right); } } while (cw_clip_math >>= 1, ++windex < cwin.nr); // Clear out stuff on the sides. if (ppu->extraLeftRight - ppu->extraLeftCur != 0) memset(dst_org, 0, sizeof(uint32) * (ppu->extraLeftRight - ppu->extraLeftCur)); if (ppu->extraLeftRight - ppu->extraRightCur != 0) memset(dst_org + (256 + ppu->extraLeftRight * 2 - (ppu->extraLeftRight - ppu->extraRightCur)), 0, sizeof(uint32) * (ppu->extraLeftRight - ppu->extraRightCur)); } static void ppu_handlePixel(Ppu* ppu, int x, int y) { int r = 0, r2 = 0; int g = 0, g2 = 0; int b = 0, b2 = 0; if (!ppu->forcedBlank) { int mainLayer = ppu_getPixel(ppu, x, y, false, &r, &g, &b); bool colorWindowState = ppu_getWindowState(ppu, 5, x); if ( ppu->clipMode == 3 || (ppu->clipMode == 2 && colorWindowState) || (ppu->clipMode == 1 && !colorWindowState) ) { r = g = b = 0; } int secondLayer = 5; // backdrop bool mathEnabled = mainLayer < 6 && (ppu->mathEnabled & (1 << mainLayer)) && !( ppu->preventMathMode == 3 || (ppu->preventMathMode == 2 && colorWindowState) || (ppu->preventMathMode == 1 && !colorWindowState) ); if ((mathEnabled && ppu->addSubscreen) || ppu->mode == 5 || ppu->mode == 6) { secondLayer = ppu_getPixel(ppu, x, y, true, &r2, &g2, &b2); } // TODO: subscreen pixels can be clipped to black as well // TODO: math for subscreen pixels (add/sub sub to main) if (mathEnabled) { if (ppu->subtractColor) { r -= (ppu->addSubscreen && secondLayer != 5) ? r2 : ppu->fixedColorR; g -= (ppu->addSubscreen && secondLayer != 5) ? g2 : ppu->fixedColorG; b -= (ppu->addSubscreen && secondLayer != 5) ? b2 : ppu->fixedColorB; } else { r += (ppu->addSubscreen && secondLayer != 5) ? r2 : ppu->fixedColorR; g += (ppu->addSubscreen && secondLayer != 5) ? g2 : ppu->fixedColorG; b += (ppu->addSubscreen && secondLayer != 5) ? b2 : ppu->fixedColorB; } if (ppu->halfColor && (secondLayer != 5 || !ppu->addSubscreen)) { r >>= 1; g >>= 1; b >>= 1; } if (r > 31) r = 31; if (g > 31) g = 31; if (b > 31) b = 31; if (r < 0) r = 0; if (g < 0) g = 0; if (b < 0) b = 0; } if (!(ppu->mode == 5 || ppu->mode == 6)) { r2 = r; g2 = g; b2 = b; } } int row = y - 1; uint8 *pixelBuffer = (uint8*) &ppu->renderBuffer[row * ppu->renderPitch + (x + ppu->extraLeftRight) * 4]; pixelBuffer[0] = ((b << 3) | (b >> 2)) * ppu->brightness / 15; pixelBuffer[1] = ((g << 3) | (g >> 2)) * ppu->brightness / 15; pixelBuffer[2] = ((r << 3) | (r >> 2)) * ppu->brightness / 15; pixelBuffer[3] = 0; } static const int bitDepthsPerMode[10][4] = { {2, 2, 2, 2}, {4, 4, 2, 5}, {4, 4, 5, 5}, {8, 4, 5, 5}, {8, 2, 5, 5}, {4, 2, 5, 5}, {4, 5, 5, 5}, {8, 5, 5, 5}, {4, 4, 2, 5}, {8, 7, 5, 5} }; static int ppu_getPixel(Ppu *ppu, int x, int y, bool sub, int *r, int *g, int *b) { // array for layer definitions per mode: // 0-7: mode 0-7; 8: mode 1 + l3prio; 9: mode 7 + extbg // 0-3; layers 1-4; 4: sprites; 5: nonexistent static const int layersPerMode[10][12] = { {4, 0, 1, 4, 0, 1, 4, 2, 3, 4, 2, 3}, {4, 0, 1, 4, 0, 1, 4, 2, 4, 2, 5, 5}, {4, 0, 4, 1, 4, 0, 4, 1, 5, 5, 5, 5}, {4, 0, 4, 1, 4, 0, 4, 1, 5, 5, 5, 5}, {4, 0, 4, 1, 4, 0, 4, 1, 5, 5, 5, 5}, {4, 0, 4, 1, 4, 0, 4, 1, 5, 5, 5, 5}, {4, 0, 4, 4, 0, 4, 5, 5, 5, 5, 5, 5}, {4, 4, 4, 0, 4, 5, 5, 5, 5, 5, 5, 5}, {2, 4, 0, 1, 4, 0, 1, 4, 4, 2, 5, 5}, {4, 4, 1, 4, 0, 4, 1, 5, 5, 5, 5, 5} }; static const int prioritysPerMode[10][12] = { {3, 1, 1, 2, 0, 0, 1, 1, 1, 0, 0, 0}, {3, 1, 1, 2, 0, 0, 1, 1, 0, 0, 5, 5}, {3, 1, 2, 1, 1, 0, 0, 0, 5, 5, 5, 5}, {3, 1, 2, 1, 1, 0, 0, 0, 5, 5, 5, 5}, {3, 1, 2, 1, 1, 0, 0, 0, 5, 5, 5, 5}, {3, 1, 2, 1, 1, 0, 0, 0, 5, 5, 5, 5}, {3, 1, 2, 1, 0, 0, 5, 5, 5, 5, 5, 5}, {3, 2, 1, 0, 0, 5, 5, 5, 5, 5, 5, 5}, {1, 3, 1, 1, 2, 0, 0, 1, 0, 0, 5, 5}, {3, 2, 1, 1, 0, 0, 0, 5, 5, 5, 5, 5} }; static const int layerCountPerMode[10] = { 12, 10, 8, 8, 8, 8, 6, 5, 10, 7 }; // figure out which color is on this location on main- or subscreen, sets it in r, g, b // returns which layer it is: 0-3 for bg layer, 4 or 6 for sprites (depending on palette), 5 for backdrop int actMode = ppu->mode == 1 ? 8 : ppu->mode; actMode = ppu->mode == 7 && ppu->m7extBg_always_zero ? 9 : actMode; int layer = 5; int pixel = 0; for (int i = 0; i < layerCountPerMode[actMode]; i++) { int curLayer = layersPerMode[actMode][i]; int curPriority = prioritysPerMode[actMode][i]; bool layerActive = false; if (!sub) { layerActive = IS_SCREEN_ENABLED(ppu, 0, curLayer) && ( !IS_SCREEN_WINDOWED(ppu, 0, curLayer) || !ppu_getWindowState(ppu, curLayer, x) ); } else { layerActive = IS_SCREEN_ENABLED(ppu, 1, curLayer) && ( !IS_SCREEN_WINDOWED(ppu, 1, curLayer) || !ppu_getWindowState(ppu, curLayer, x) ); } if (layerActive) { if (curLayer < 4) { // bg layer int lx = x; int ly = y; if (IS_MOSAIC_ENABLED(ppu, curLayer)) { lx -= lx % ppu->mosaicSize; ly -= (ly - 1) % ppu->mosaicSize; } if (ppu->mode == 7) { pixel = ppu_getPixelForMode7(ppu, lx, curLayer, curPriority); } else { lx += ppu->bgLayer[curLayer].hScroll; ly += ppu->bgLayer[curLayer].vScroll; pixel = ppu_getPixelForBgLayer( ppu, lx & 0x3ff, ly & 0x3ff, curLayer, curPriority ); } } else { // get a pixel from the sprite buffer pixel = 0; if ((ppu->objBuffer.data[x + kPpuExtraLeftRight] >> 12) == SPRITE_PRIO_TO_PRIO_HI(curPriority)) pixel = ppu->objBuffer.data[x + kPpuExtraLeftRight] & 0xff; } } if (pixel > 0) { layer = curLayer; break; } } uint16_t color = ppu->cgram[pixel & 0xff]; *r = color & 0x1f; *g = (color >> 5) & 0x1f; *b = (color >> 10) & 0x1f; if (layer == 4 && pixel < 0xc0) layer = 6; // sprites with palette color < 0xc0 return layer; } static int ppu_getPixelForBgLayer(Ppu *ppu, int x, int y, int layer, bool priority) { BgLayer *layerp = &ppu->bgLayer[layer]; // figure out address of tilemap word and read it bool wideTiles = ppu->mode == 5 || ppu->mode == 6; int tileBitsX = wideTiles ? 4 : 3; int tileHighBitX = wideTiles ? 0x200 : 0x100; int tileBitsY = 3; int tileHighBitY = 0x100; uint16_t tilemapAdr = layerp->tilemapAdr + (((y >> tileBitsY) & 0x1f) << 5 | ((x >> tileBitsX) & 0x1f)); if ((x & tileHighBitX) && layerp->tilemapWider) tilemapAdr += 0x400; if ((y & tileHighBitY) && layerp->tilemapHigher) tilemapAdr += layerp->tilemapWider ? 0x800 : 0x400; uint16_t tile = ppu->vram[tilemapAdr & 0x7fff]; // check priority, get palette if (((bool)(tile & 0x2000)) != priority) return 0; // wrong priority int paletteNum = (tile & 0x1c00) >> 10; // figure out position within tile int row = (tile & 0x8000) ? 7 - (y & 0x7) : (y & 0x7); int col = (tile & 0x4000) ? (x & 0x7) : 7 - (x & 0x7); int tileNum = tile & 0x3ff; if (wideTiles) { // if unflipped right half of tile, or flipped left half of tile if (((bool)(x & 8)) ^ ((bool)(tile & 0x4000))) tileNum += 1; } // read tiledata, ajust palette for mode 0 int bitDepth = bitDepthsPerMode[ppu->mode][layer]; if (ppu->mode == 0) paletteNum += 8 * layer; // plane 1 (always) int paletteSize = 4; uint16_t plane1 = ppu->vram[(layerp->tileAdr + ((tileNum & 0x3ff) * 4 * bitDepth) + row) & 0x7fff]; int pixel = (plane1 >> col) & 1; pixel |= ((plane1 >> (8 + col)) & 1) << 1; // plane 2 (for 4bpp, 8bpp) if (bitDepth > 2) { paletteSize = 16; uint16_t plane2 = ppu->vram[(layerp->tileAdr + ((tileNum & 0x3ff) * 4 * bitDepth) + 8 + row) & 0x7fff]; pixel |= ((plane2 >> col) & 1) << 2; pixel |= ((plane2 >> (8 + col)) & 1) << 3; } // plane 3 & 4 (for 8bpp) if (bitDepth > 4) { paletteSize = 256; uint16_t plane3 = ppu->vram[(layerp->tileAdr + ((tileNum & 0x3ff) * 4 * bitDepth) + 16 + row) & 0x7fff]; pixel |= ((plane3 >> col) & 1) << 4; pixel |= ((plane3 >> (8 + col)) & 1) << 5; uint16_t plane4 = ppu->vram[(layerp->tileAdr + ((tileNum & 0x3ff) * 4 * bitDepth) + 24 + row) & 0x7fff]; pixel |= ((plane4 >> col) & 1) << 6; pixel |= ((plane4 >> (8 + col)) & 1) << 7; } // return cgram index, or 0 if transparent, palette number in bits 10-8 for 8-color layers return pixel == 0 ? 0 : paletteSize * paletteNum + pixel; } static void ppu_calculateMode7Starts(Ppu* ppu, int y) { // expand 13-bit values to signed values int hScroll = ((int16_t) (ppu->m7matrix[6] << 3)) >> 3; int vScroll = ((int16_t) (ppu->m7matrix[7] << 3)) >> 3; int xCenter = ((int16_t) (ppu->m7matrix[4] << 3)) >> 3; int yCenter = ((int16_t) (ppu->m7matrix[5] << 3)) >> 3; // do calculation int clippedH = hScroll - xCenter; int clippedV = vScroll - yCenter; clippedH = (clippedH & 0x2000) ? (clippedH | ~1023) : (clippedH & 1023); clippedV = (clippedV & 0x2000) ? (clippedV | ~1023) : (clippedV & 1023); if(IS_MOSAIC_ENABLED(ppu, 0)) { y -= (y - 1) % ppu->mosaicSize; } uint8_t ry = ppu->m7yFlip ? 255 - y : y; ppu->m7startX = ( ((ppu->m7matrix[0] * clippedH) & ~63) + ((ppu->m7matrix[1] * ry) & ~63) + ((ppu->m7matrix[1] * clippedV) & ~63) + (xCenter << 8) ); ppu->m7startY = ( ((ppu->m7matrix[2] * clippedH) & ~63) + ((ppu->m7matrix[3] * ry) & ~63) + ((ppu->m7matrix[3] * clippedV) & ~63) + (yCenter << 8) ); } static int ppu_getPixelForMode7(Ppu* ppu, int x, int layer, bool priority) { if (IS_MOSAIC_ENABLED(ppu, layer)) x -= x % ppu->mosaicSize; uint8_t rx = ppu->m7xFlip ? 255 - x : x; int xPos = (ppu->m7startX + ppu->m7matrix[0] * rx) >> 8; int yPos = (ppu->m7startY + ppu->m7matrix[2] * rx) >> 8; bool outsideMap = xPos < 0 || xPos >= 1024 || yPos < 0 || yPos >= 1024; xPos &= 0x3ff; yPos &= 0x3ff; if(!ppu->m7largeField) outsideMap = false; uint8_t tile = outsideMap ? 0 : ppu->vram[(yPos >> 3) * 128 + (xPos >> 3)] & 0xff; uint8_t pixel = outsideMap && !ppu->m7charFill ? 0 : ppu->vram[tile * 64 + (yPos & 7) * 8 + (xPos & 7)] >> 8; if(layer == 1) { if(((bool) (pixel & 0x80)) != priority) return 0; return pixel & 0x7f; } return pixel; } static bool ppu_getWindowState(Ppu* ppu, int layer, int x) { uint32 winflags = GET_WINDOW_FLAGS(ppu, layer); if (!(winflags & kWindow1Enabled) && !(winflags & kWindow2Enabled)) { return false; } if ((winflags & kWindow1Enabled) && !(winflags & kWindow2Enabled)) { bool test = x >= ppu->window1left && x <= ppu->window1right; return (winflags & kWindow1Inversed) ? !test : test; } if (!(winflags & kWindow1Enabled) && (winflags & kWindow2Enabled)) { bool test = x >= ppu->window2left && x <= ppu->window2right; return (winflags & kWindow2Inversed) ? !test : test; } bool test1 = x >= ppu->window1left && x <= ppu->window1right; bool test2 = x >= ppu->window2left && x <= ppu->window2right; if (winflags & kWindow1Inversed) test1 = !test1; if (winflags & kWindow2Inversed) test2 = !test2; return test1 || test2; } static bool ppu_evaluateSprites(Ppu* ppu, int line) { // TODO: iterate over oam normally to determine in-range sprites, // then iterate those in-range sprites in reverse for tile-fetching // TODO: rectangular sprites, wierdness with sprites at -256 int index = 0, index_end = index; int spritesLeft = 32 + 1, tilesLeft = 34 + 1; uint8 spriteSizes[2] = { kSpriteSizes[ppu->objSize][0], kSpriteSizes[ppu->objSize][1] }; int extra_left_right = ppu->extraLeftRight; if (ppu->renderFlags & kPpuRenderFlags_NoSpriteLimits) spritesLeft = tilesLeft = 1024; int tilesLeftOrg = tilesLeft; do { int yy = ppu->oam[index] >> 8; if (yy == 0xf0) continue; // this works for zelda because sprites are always 8 or 16. // check if the sprite is on this line and get the sprite size int row = (line - yy) & 0xff; int highOam = ppu->oam[0x100 + (index >> 4)] >> (index & 15); int spriteSize = spriteSizes[(highOam >> 1) & 1]; if (row >= spriteSize) continue; // in y-range, get the x location, using the high bit as well int x = (ppu->oam[index] & 0xff) + (highOam & 1) * 256; x -= (x >= 256 + extra_left_right) * 512; // if in x-range if (x <= -(spriteSize + extra_left_right)) continue; // break if we found 32 sprites already if (--spritesLeft == 0) { break; } // get some data for the sprite and y-flip row if needed int oam1 = ppu->oam[index + 1]; int objAdr = (oam1 & 0x100) ? ppu->objTileAdr2 : ppu->objTileAdr1; if (oam1 & 0x8000) row = spriteSize - 1 - row; // fetch all tiles in x-range int paletteBase = 0x80 + 16 * ((oam1 & 0xe00) >> 9); int prio = SPRITE_PRIO_TO_PRIO((oam1 & 0x3000) >> 12, (oam1 & 0x800) == 0); PpuZbufType z = paletteBase + (prio << 8); for (int col = 0; col < spriteSize; col += 8) { if (col + x > -8 - extra_left_right && col + x < 256 + extra_left_right) { // break if we found 34 8*1 slivers already if (--tilesLeft == 0) { return true; } // figure out which tile this uses, looping within 16x16 pages, and get it's data int usedCol = oam1 & 0x4000 ? spriteSize - 1 - col : col; int usedTile = ((((oam1 & 0xff) >> 4) + (row >> 3)) << 4) | (((oam1 & 0xf) + (usedCol >> 3)) & 0xf); uint16 *addr = &ppu->vram[(objAdr + usedTile * 16 + (row & 0x7)) & 0x7fff]; uint32 plane = addr[0] | addr[8] << 16; // go over each pixel int px_left = IntMax(-(col + x + kPpuExtraLeftRight), 0); int px_right = IntMin(256 + kPpuExtraLeftRight - (col + x), 8); PpuZbufType *dst = ppu->objBuffer.data + col + x + px_left + kPpuExtraLeftRight; for (int px = px_left; px < px_right; px++, dst++) { int shift = oam1 & 0x4000 ? px : 7 - px; uint32 bits = plane >> shift; int pixel = (bits >> 0) & 1 | (bits >> 7) & 2 | (bits >> 14) & 4 | (bits >> 21) & 8; // draw it in the buffer if there is a pixel here, and the buffer there is still empty if (pixel != 0 && (dst[0] & 0xff) == 0) dst[0] = z + pixel; } } } } while ((index = (index + 2) & 0xff) != index_end); return (tilesLeft != tilesLeftOrg); } uint8_t ppu_read(Ppu* ppu, uint8_t adr) { switch (adr) { case 0x34: case 0x35: case 0x36: { int result = ppu->m7matrix[0] * (ppu->m7matrix[1] >> 8); return (result >> (8 * (adr - 0x34))) & 0xff; } } return 0xff; } void ppu_write(Ppu* ppu, uint8_t adr, uint8_t val) { switch(adr) { case 0x00: { // INIDISP ppu->brightness = val & 0xf; ppu->forcedBlank = val & 0x80; break; } case 0x01: { assert(val == 2); break; } case 0x02: { ppu->oamAdr = (ppu->oamAdr & ~0xff) | val; ppu->oamSecondWrite = false; break; } case 0x03: { assert((val & 0x80) == 0); ppu->oamAdr = (ppu->oamAdr & ~0xff00) | ((val & 1) << 8); ppu->oamSecondWrite = false; break; } case 0x04: { if (!ppu->oamSecondWrite) { ppu->oamBuffer = val; } else { if (ppu->oamAdr < 0x110) ppu->oam[ppu->oamAdr++] = (val << 8) | ppu->oamBuffer; } ppu->oamSecondWrite = !ppu->oamSecondWrite; break; } case 0x05: { // BGMODE ppu->mode = val & 0x7; assert(val == 7 || val == 9); assert(ppu->mode == 1 || ppu->mode == 7); assert((val & 0xf0) == 0); break; } case 0x06: { // MOSAIC ppu->mosaicSize = (val >> 4) + 1; ppu->mosaicEnabled = (ppu->mosaicSize > 1) ? val : 0; break; } case 0x07: // BG1SC case 0x08: case 0x09: case 0x0a: { // small tilemaps are used in attract intro ppu->bgLayer[adr - 7].tilemapWider = val & 0x1; ppu->bgLayer[adr - 7].tilemapHigher = val & 0x2; ppu->bgLayer[adr - 7].tilemapAdr = (val & 0xfc) << 8; break; } case 0x0b: { // BG12NBA ppu->bgLayer[0].tileAdr = (val & 0xf) << 12; ppu->bgLayer[1].tileAdr = (val & 0xf0) << 8; break; } case 0x0c: { // BG34NBA ppu->bgLayer[2].tileAdr = (val & 0xf) << 12; ppu->bgLayer[3].tileAdr = (val & 0xf0) << 8; break; } case 0x0d: { // BG1HOFS ppu->m7matrix[6] = ((val << 8) | ppu->m7prev) & 0x1fff; ppu->m7prev = val; // fallthrough to normal layer BG-HOFS } case 0x0f: case 0x11: case 0x13: { ppu->bgLayer[(adr - 0xd) / 2].hScroll = ((val << 8) | (ppu->scrollPrev & 0xf8) | (ppu->scrollPrev2 & 0x7)) & 0x3ff; ppu->scrollPrev = val; ppu->scrollPrev2 = val; break; } case 0x0e: { // BG1VOFS ppu->m7matrix[7] = ((val << 8) | ppu->m7prev) & 0x1fff; ppu->m7prev = val; // fallthrough to normal layer BG-VOFS } case 0x10: case 0x12: case 0x14: { ppu->bgLayer[(adr - 0xe) / 2].vScroll = ((val << 8) | ppu->scrollPrev) & 0x3ff; ppu->scrollPrev = val; break; } case 0x15: { // VMAIN if((val & 3) == 0) { ppu->vramIncrement = 1; } else if((val & 3) == 1) { ppu->vramIncrement = 32; } else { ppu->vramIncrement = 128; } assert(((val & 0xc) >> 2) == 0); ppu->vramIncrementOnHigh = val & 0x80; break; } case 0x16: { // VMADDL ppu->vramPointer = (ppu->vramPointer & 0xff00) | val; break; } case 0x17: { // VMADDH ppu->vramPointer = (ppu->vramPointer & 0x00ff) | (val << 8); break; } case 0x18: { // VMDATAL uint16_t vramAdr = ppu->vramPointer; ppu->vram[vramAdr & 0x7fff] = (ppu->vram[vramAdr & 0x7fff] & 0xff00) | val; if(!ppu->vramIncrementOnHigh) ppu->vramPointer += ppu->vramIncrement; break; } case 0x19: { // VMDATAH uint16_t vramAdr = ppu->vramPointer; ppu->vram[vramAdr & 0x7fff] = (ppu->vram[vramAdr & 0x7fff] & 0x00ff) | (val << 8); if(ppu->vramIncrementOnHigh) ppu->vramPointer += ppu->vramIncrement; break; } case 0x1a: { // M7SEL assert(val == 0x80); ppu->m7largeField = val & 0x80; ppu->m7charFill = val & 0x40; ppu->m7yFlip = val & 0x2; ppu->m7xFlip = val & 0x1; break; } case 0x1b: // M7A etc case 0x1c: case 0x1d: case 0x1e: { ppu->m7matrix[adr - 0x1b] = (val << 8) | ppu->m7prev; ppu->m7prev = val; break; } case 0x1f: case 0x20: { ppu->m7matrix[adr - 0x1b] = ((val << 8) | ppu->m7prev) & 0x1fff; ppu->m7prev = val; break; } case 0x21: { ppu->cgramPointer = val; ppu->cgramSecondWrite = false; break; } case 0x22: { if(!ppu->cgramSecondWrite) { ppu->cgramBuffer = val; } else { ppu->cgram[ppu->cgramPointer++] = (val << 8) | ppu->cgramBuffer; } ppu->cgramSecondWrite = !ppu->cgramSecondWrite; break; } case 0x23: // W12SEL ppu->windowsel = (ppu->windowsel & ~0xff) | val; break; case 0x24: // W34SEL ppu->windowsel = (ppu->windowsel & ~0xff00) | (val << 8); break; case 0x25: // WOBJSEL ppu->windowsel = (ppu->windowsel & ~0xff0000) | (val << 16); break; case 0x26: ppu->window1left = val; break; case 0x27: ppu->window1right = val; break; case 0x28: ppu->window2left = val; break; case 0x29: ppu->window2right = val; break; case 0x2a: // WBGLOG assert(val == 0); break; case 0x2b: // WOBJLOG assert(val == 0); break; case 0x2c: // TM ppu->screenEnabled[0] = val; break; case 0x2d: // TS ppu->screenEnabled[1] = val; break; case 0x2e: // TMW ppu->screenWindowed[0] = val; break; case 0x2f: // TSW ppu->screenWindowed[1] = val; break; case 0x30: { // CGWSEL assert((val & 1) == 0); // directColor always zero ppu->addSubscreen = val & 0x2; ppu->preventMathMode = (val & 0x30) >> 4; ppu->clipMode = (val & 0xc0) >> 6; break; } case 0x31: { // CGADSUB ppu->subtractColor = val & 0x80; ppu->halfColor = val & 0x40; ppu->mathEnabled = val & 0x3f; break; } case 0x32: { // COLDATA if(val & 0x80) ppu->fixedColorB = val & 0x1f; if(val & 0x40) ppu->fixedColorG = val & 0x1f; if(val & 0x20) ppu->fixedColorR = val & 0x1f; break; } case 0x33: { assert(val == 0); ppu->m7extBg_always_zero = val & 0x40; break; } default: { break; } } }