DS Video: Add extended BG palettes

include/mgba/internal/ds/renderers/software.h

@@ -27,6 +27,11 @@ struct DSVideoSoftwareRenderer {
 	int outputBufferStride;
 
 	uint32_t row[DS_VIDEO_HORIZONTAL_PIXELS];
+
+	color_t extPaletteA[16384];
+	color_t extPaletteB[16384];
+	color_t variantPaletteA[16384];
+	color_t variantPaletteB[16384];
 };
 
 void DSVideoSoftwareRendererCreate(struct DSVideoSoftwareRenderer* renderer);

include/mgba/internal/ds/video.h

@@ -57,11 +57,15 @@ DECL_BITS(DSRegisterDISPCNT, TileBoundary, 20, 2);
 DECL_BITS(DSRegisterDISPCNT, CharBase, 24, 3);
 DECL_BITS(DSRegisterDISPCNT, ScreenBase, 27, 3);
 // TODO
+DECL_BIT(DSRegisterDISPCNT, BgExtPalette, 30);
+DECL_BIT(DSRegisterDISPCNT, ObjExtPalette, 31);
 
 DECL_BITFIELD(DSRegisterPOWCNT1, uint16_t);
 // TODO
 DECL_BIT(DSRegisterPOWCNT1, Swap, 15);
 
+DECL_BIT(GBARegisterBGCNT, ExtPaletteSlot, 13);
+
 struct DSVideoRenderer {
 	void (*init)(struct DSVideoRenderer* renderer);
 	void (*reset)(struct DSVideoRenderer* renderer);
@@ -70,6 +74,7 @@ struct DSVideoRenderer {
 	uint16_t (*writeVideoRegister)(struct DSVideoRenderer* renderer, uint32_t address, uint16_t value);
 	void (*writePalette)(struct DSVideoRenderer* renderer, uint32_t address, uint16_t value);
 	void (*writeOAM)(struct DSVideoRenderer* renderer, uint32_t oam);
+	void (*invalidateExtPal)(struct DSVideoRenderer* renderer, bool obj, bool engB, int slot);
 	void (*drawScanline)(struct DSVideoRenderer* renderer, int y);
 	void (*finishFrame)(struct DSVideoRenderer* renderer);
 
@@ -80,8 +85,12 @@ struct DSVideoRenderer {
 	uint16_t* vram;
 	uint16_t* vramABG[32];
 	uint16_t* vramAOBJ[32];
+	uint16_t* vramABGExtPal[4];
+	uint16_t* vramAOBJExtPal[4];
 	uint16_t* vramBBG[32];
 	uint16_t* vramBOBJ[32];
+	uint16_t* vramBBGExtPal[4];
+	uint16_t* vramBOBJExtPal[4];
 	union DSOAM* oam;
 };
 
@@ -99,8 +108,12 @@ struct DSVideo {
 	uint16_t* vram;
 	uint16_t* vramABG[32];
 	uint16_t* vramAOBJ[32];
+	uint16_t* vramABGExtPal[4];
+	uint16_t* vramAOBJExtPal[4];
 	uint16_t* vramBBG[32];
 	uint16_t* vramBOBJ[32];
+	uint16_t* vramBBGExtPal[4];
+	uint16_t* vramBOBJExtPal[4];
 	union DSOAM oam;
 
 	int32_t frameCounter;
@@ -117,7 +130,7 @@ struct DSCommon;
 void DSVideoWriteDISPSTAT(struct DSCommon* dscore, uint16_t value);
 
 struct DSMemory;
-void DSVideoConfigureVRAM(struct DS* ds, int index, uint8_t value);
+void DSVideoConfigureVRAM(struct DS* ds, int index, uint8_t value, uint8_t oldValue);
 
 CXX_GUARD_START
 

include/mgba/internal/gba/renderers/video-software.h

@@ -42,6 +42,8 @@ struct GBAVideoSoftwareBackground {
 	int16_t dmy;
 	int32_t sx;
 	int32_t sy;
+	color_t* extPalette;
+	color_t* variantPalette;
 };
 
 enum BlendEffect {
@@ -116,7 +118,7 @@ struct GBAVideoSoftwareRenderer {
 
 	uint32_t* temporaryBuffer;
 
-	GBARegisterDISPCNT dispcnt;
+	uint32_t dispcnt;
 
 	uint32_t row[256];
 	uint32_t spriteLayer[256];

src/ds/io.c

@@ -424,24 +424,28 @@ void DS9IOWrite(struct DS* ds, uint32_t address, uint16_t value) {
 	} else if (address >= DS9_REG_B_DISPCNT_LO && address <= DS9_REG_B_BLDY) {
 		value = ds->video.renderer->writeVideoRegister(ds->video.renderer, address, value);
 	} else {
+		uint16_t oldValue;
 		switch (address) {
 		// VRAM control
 		case DS9_REG_VRAMCNT_A:
 		case DS9_REG_VRAMCNT_C:
 		case DS9_REG_VRAMCNT_E:
+			oldValue = ds->memory.io9[address >> 1];
 			value &= 0x9F9F;
-			DSVideoConfigureVRAM(ds, address - DS9_REG_VRAMCNT_A, value & 0xFF);
+			DSVideoConfigureVRAM(ds, address - DS9_REG_VRAMCNT_A, value & 0xFF, oldValue & 0xFF);
-			DSVideoConfigureVRAM(ds, address - DS9_REG_VRAMCNT_A + 1, value >> 8);
+			DSVideoConfigureVRAM(ds, address - DS9_REG_VRAMCNT_A + 1, value >> 8, oldValue >> 8);
 			break;
 		case DS9_REG_VRAMCNT_G:
+			oldValue = ds->memory.io9[address >> 1];
 			value &= 0x9F03;
-			DSVideoConfigureVRAM(ds, 6, value & 0xFF);
+			DSVideoConfigureVRAM(ds, 6, value & 0xFF, oldValue & 0xFF);
 			DSConfigureWRAM(&ds->memory, value >> 8);
 			break;
 		case DS9_REG_VRAMCNT_H:
+			oldValue = ds->memory.io9[address >> 1];
 			value &= 0x9F9F;
-			DSVideoConfigureVRAM(ds, 7, value & 0xFF);
+			DSVideoConfigureVRAM(ds, 7, value & 0xFF, oldValue & 0xFF);
-			DSVideoConfigureVRAM(ds, 8, value >> 8);
+			DSVideoConfigureVRAM(ds, 8, value >> 8, oldValue >> 8);
 			break;
 
 		case DS9_REG_EXMEMCNT:

src/ds/memory.c

@@ -202,15 +202,15 @@ void DSMemoryReset(struct DS* ds) {
 	DSSPIReset(ds);
 	DSSlot1Reset(ds);
 
-	DSVideoConfigureVRAM(ds, 0, 0);
+	DSVideoConfigureVRAM(ds, 0, 0, 1);
-	DSVideoConfigureVRAM(ds, 1, 0);
+	DSVideoConfigureVRAM(ds, 1, 0, 1);
-	DSVideoConfigureVRAM(ds, 2, 0);
+	DSVideoConfigureVRAM(ds, 2, 0, 1);
-	DSVideoConfigureVRAM(ds, 3, 0);
+	DSVideoConfigureVRAM(ds, 3, 0, 1);
-	DSVideoConfigureVRAM(ds, 4, 0);
+	DSVideoConfigureVRAM(ds, 4, 0, 1);
-	DSVideoConfigureVRAM(ds, 5, 0);
+	DSVideoConfigureVRAM(ds, 5, 0, 1);
-	DSVideoConfigureVRAM(ds, 6, 0);
+	DSVideoConfigureVRAM(ds, 6, 0, 1);
-	DSVideoConfigureVRAM(ds, 7, 0);
+	DSVideoConfigureVRAM(ds, 7, 0, 1);
-	DSVideoConfigureVRAM(ds, 8, 0);
+	DSVideoConfigureVRAM(ds, 8, 0, 1);
 	DSConfigureWRAM(&ds->memory, 3);
 
 	if (!ds->memory.wram || !ds->memory.wram7 || !ds->memory.ram || !ds->memory.itcm || !ds->memory.dtcm) {

src/ds/renderers/software.c

@@ -4,6 +4,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include <mgba/internal/ds/renderers/software.h>
+#include "gba/renderers/software-private.h"
 
 #include <mgba/internal/arm/macros.h>
 #include <mgba/internal/ds/io.h>
@@ -14,11 +15,61 @@ static void DSVideoSoftwareRendererReset(struct DSVideoRenderer* renderer);
 static uint16_t DSVideoSoftwareRendererWriteVideoRegister(struct DSVideoRenderer* renderer, uint32_t address, uint16_t value);
 static void DSVideoSoftwareRendererWritePalette(struct DSVideoRenderer* renderer, uint32_t address, uint16_t value);
 static void DSVideoSoftwareRendererWriteOAM(struct DSVideoRenderer* renderer, uint32_t oam);
+static void DSVideoSoftwareRendererInvalidateExtPal(struct DSVideoRenderer* renderer, bool obj, bool engB, int slot);
 static void DSVideoSoftwareRendererDrawScanline(struct DSVideoRenderer* renderer, int y);
 static void DSVideoSoftwareRendererFinishFrame(struct DSVideoRenderer* renderer);
 static void DSVideoSoftwareRendererGetPixels(struct DSVideoRenderer* renderer, size_t* stride, const void** pixels);
 static void DSVideoSoftwareRendererPutPixels(struct DSVideoRenderer* renderer, size_t stride, const void* pixels);
 
+static bool _regenerateExtPalette(struct DSVideoSoftwareRenderer* renderer, bool engB, int slot) {
+	color_t* palette;
+	color_t* variantPalette;
+	struct GBAVideoSoftwareRenderer* softwareRenderer;
+	uint16_t* vram;
+	if (!engB) {
+		palette = &renderer->extPaletteA[slot * 4096];
+		variantPalette = &renderer->variantPaletteA[slot * 4096];
+		softwareRenderer = &renderer->engA;
+		vram = renderer->d.vramABGExtPal[slot];
+	} else {
+		palette = &renderer->extPaletteB[slot * 4096];
+		variantPalette = &renderer->variantPaletteB[slot * 4096];
+		softwareRenderer = &renderer->engB;
+		vram = renderer->d.vramBBGExtPal[slot];
+	}
+	if (!vram) {
+		return false;
+	}
+	int i;
+	for (i = 0; i < 4096; ++i) {
+		uint16_t value = vram[i];
+#ifdef COLOR_16_BIT
+#ifdef COLOR_5_6_5
+		unsigned color = 0;
+		color |= (value & 0x001F) << 11;
+		color |= (value & 0x03E0) << 1;
+		color |= (value & 0x7C00) >> 10;
+#else
+		unsigned color = value;
+#endif
+#else
+		unsigned color = 0;
+		color |= (value << 3) & 0xF8;
+		color |= (value << 6) & 0xF800;
+		color |= (value << 9) & 0xF80000;
+		color |= (color >> 5) & 0x070707;
+#endif
+		palette[i] = color;
+		if (softwareRenderer->blendEffect == BLEND_BRIGHTEN) {
+			variantPalette[i] = _brighten(color, softwareRenderer->bldy);
+		} else if (softwareRenderer->blendEffect == BLEND_DARKEN) {
+			variantPalette[i] = _darken(color, softwareRenderer->bldy);
+		}
+	}
+	return true;
+}
+
+
 void DSVideoSoftwareRendererCreate(struct DSVideoSoftwareRenderer* renderer) {
 	renderer->d.init = DSVideoSoftwareRendererInit;
 	renderer->d.reset = DSVideoSoftwareRendererReset;
@@ -26,6 +77,7 @@ void DSVideoSoftwareRendererCreate(struct DSVideoSoftwareRenderer* renderer) {
 	renderer->d.writeVideoRegister = DSVideoSoftwareRendererWriteVideoRegister;
 	renderer->d.writePalette = DSVideoSoftwareRendererWritePalette;
 	renderer->d.writeOAM = DSVideoSoftwareRendererWriteOAM;
+	renderer->d.invalidateExtPal = DSVideoSoftwareRendererInvalidateExtPal;
 	renderer->d.drawScanline = DSVideoSoftwareRendererDrawScanline;
 	renderer->d.finishFrame = DSVideoSoftwareRendererFinishFrame;
 	renderer->d.getPixels = DSVideoSoftwareRendererGetPixels;
@@ -75,6 +127,25 @@ static void DSVideoSoftwareRendererUpdateDISPCNTA(struct DSVideoSoftwareRenderer
 		fakeDispcnt = GBARegisterDISPCNTFillObjCharacterMapping(fakeDispcnt);
 	}
 	softwareRenderer->engA.d.writeVideoRegister(&softwareRenderer->engA.d, DS9_REG_A_DISPCNT_LO, fakeDispcnt);
+	softwareRenderer->engA.dispcnt |= softwareRenderer->dispcntA & 0xFFFF000;
+	if (DSRegisterDISPCNTIsBgExtPalette(softwareRenderer->dispcntA)) {
+		int i;
+		for (i = 0; i < 4; ++i) {
+			// TODO: Regenerate on change
+			int slot = i;
+			if (i < 2 && GBARegisterBGCNTIsExtPaletteSlot(softwareRenderer->engA.bg[i].control)) {
+				slot += 2;
+			}
+			if (softwareRenderer->engA.bg[i].extPalette != &softwareRenderer->extPaletteA[slot * 4096] && _regenerateExtPalette(softwareRenderer, false, slot)) {
+				softwareRenderer->engA.bg[i].extPalette = &softwareRenderer->extPaletteA[slot * 4096];
+			}
+		}
+	} else {
+		softwareRenderer->engA.bg[0].extPalette = NULL;
+		softwareRenderer->engA.bg[1].extPalette = NULL;
+		softwareRenderer->engA.bg[2].extPalette = NULL;
+		softwareRenderer->engA.bg[3].extPalette = NULL;
+	}
 	uint32_t charBase = DSRegisterDISPCNTGetCharBase(softwareRenderer->dispcntA) << 16;
 	uint32_t screenBase = DSRegisterDISPCNTGetScreenBase(softwareRenderer->dispcntA) << 16;
 	softwareRenderer->engA.d.writeVideoRegister(&softwareRenderer->engA.d, DS9_REG_A_BG0CNT, softwareRenderer->engA.bg[0].control);
@@ -96,6 +167,7 @@ static void DSVideoSoftwareRendererUpdateDISPCNTA(struct DSVideoSoftwareRenderer
 }
 
 static void DSVideoSoftwareRendererUpdateDISPCNTB(struct DSVideoSoftwareRenderer* softwareRenderer) {
+	// TODO: Share code with DISPCNTA
 	uint16_t fakeDispcnt = softwareRenderer->dispcntB & 0xFF87;
 	if (!DSRegisterDISPCNTIsTileObjMapping(softwareRenderer->dispcntB)) {
 		softwareRenderer->engB.tileStride = 0x20;
@@ -104,6 +176,25 @@ static void DSVideoSoftwareRendererUpdateDISPCNTB(struct DSVideoSoftwareRenderer
 		fakeDispcnt = GBARegisterDISPCNTFillObjCharacterMapping(fakeDispcnt);
 	}
 	softwareRenderer->engB.d.writeVideoRegister(&softwareRenderer->engB.d, DS9_REG_A_DISPCNT_LO, fakeDispcnt);
+	softwareRenderer->engB.dispcnt |= softwareRenderer->dispcntB & 0xFFFF000;
+	if (DSRegisterDISPCNTIsBgExtPalette(softwareRenderer->dispcntB)) {
+		int i;
+		for (i = 0; i < 4; ++i) {
+			// TODO: Regenerate on change
+			int slot = i;
+			if (i < 2 && GBARegisterBGCNTIsExtPaletteSlot(softwareRenderer->engB.bg[i].control)) {
+				slot += 2;
+			}
+			if (softwareRenderer->engB.bg[i].extPalette != &softwareRenderer->extPaletteB[slot * 4096] && _regenerateExtPalette(softwareRenderer, true, slot)) {
+				softwareRenderer->engB.bg[i].extPalette = &softwareRenderer->extPaletteB[slot * 4096];
+			}
+		}
+	} else {
+		softwareRenderer->engA.bg[0].extPalette = NULL;
+		softwareRenderer->engA.bg[1].extPalette = NULL;
+		softwareRenderer->engA.bg[2].extPalette = NULL;
+		softwareRenderer->engA.bg[3].extPalette = NULL;
+	}
 }
 
 static uint16_t DSVideoSoftwareRendererWriteVideoRegister(struct DSVideoRenderer* renderer, uint32_t address, uint16_t value) {
@@ -161,6 +252,89 @@ static void DSVideoSoftwareRendererWriteOAM(struct DSVideoRenderer* renderer, ui
 	}
 }
 
+static void DSVideoSoftwareRendererInvalidateExtPal(struct DSVideoRenderer* renderer, bool obj, bool engB, int slot) {
+	struct DSVideoSoftwareRenderer* softwareRenderer = (struct DSVideoSoftwareRenderer*) renderer;
+	_regenerateExtPalette(softwareRenderer, engB, slot);
+}
+
+static void DSVideoSoftwareRendererDrawGBAScanline(struct GBAVideoRenderer* renderer, int y) {
+	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
+
+	color_t* row = &softwareRenderer->outputBuffer[softwareRenderer->outputBufferStride * y];
+	if (GBARegisterDISPCNTIsForcedBlank(softwareRenderer->dispcnt)) {
+		int x;
+		for (x = 0; x < softwareRenderer->masterEnd; ++x) {
+			row[x] = GBA_COLOR_WHITE;
+		}
+		return;
+	}
+
+	GBAVideoSoftwareRendererPreprocessBuffer(softwareRenderer, y);
+	int spriteLayers = GBAVideoSoftwareRendererPreprocessSpriteLayer(softwareRenderer, y);
+
+	int w;
+	unsigned priority;
+	for (priority = 0; priority < 4; ++priority) {
+		softwareRenderer->end = 0;
+		for (w = 0; w < softwareRenderer->nWindows; ++w) {
+			softwareRenderer->start = softwareRenderer->end;
+			softwareRenderer->end = softwareRenderer->windows[w].endX;
+			softwareRenderer->currentWindow = softwareRenderer->windows[w].control;
+			if (spriteLayers & (1 << priority)) {
+				GBAVideoSoftwareRendererPostprocessSprite(softwareRenderer, priority);
+			}
+			if (TEST_LAYER_ENABLED(0)) {
+				GBAVideoSoftwareRendererDrawBackgroundMode0(softwareRenderer, &softwareRenderer->bg[0], y);
+			}
+			if (TEST_LAYER_ENABLED(1)) {
+				GBAVideoSoftwareRendererDrawBackgroundMode0(softwareRenderer, &softwareRenderer->bg[1], y);
+			}
+			if (TEST_LAYER_ENABLED(2)) {
+				switch (GBARegisterDISPCNTGetMode(softwareRenderer->dispcnt)) {
+				case 0:
+				case 1:
+				case 3:
+					GBAVideoSoftwareRendererDrawBackgroundMode0(softwareRenderer, &softwareRenderer->bg[2], y);
+					break;
+				case 2:
+				case 4:
+					GBAVideoSoftwareRendererDrawBackgroundMode2(softwareRenderer, &softwareRenderer->bg[2], y);
+					break;
+				}
+			}
+			if (TEST_LAYER_ENABLED(3)) {
+				switch (GBARegisterDISPCNTGetMode(softwareRenderer->dispcnt)) {
+				case 0:
+					GBAVideoSoftwareRendererDrawBackgroundMode0(softwareRenderer, &softwareRenderer->bg[3], y);
+					break;
+				case 1:
+				case 2:
+					GBAVideoSoftwareRendererDrawBackgroundMode2(softwareRenderer, &softwareRenderer->bg[3], y);
+					break;
+				}
+			}
+		}
+	}
+	softwareRenderer->bg[2].sx += softwareRenderer->bg[2].dmx;
+	softwareRenderer->bg[2].sy += softwareRenderer->bg[2].dmy;
+	softwareRenderer->bg[3].sx += softwareRenderer->bg[3].dmx;
+	softwareRenderer->bg[3].sy += softwareRenderer->bg[3].dmy;
+
+	GBAVideoSoftwareRendererPostprocessBuffer(softwareRenderer);
+
+#ifdef COLOR_16_BIT
+#if defined(__ARM_NEON) && !defined(__APPLE__)
+	_to16Bit(row, softwareRenderer->row, softwareRenderer->masterEnd);
+#else
+	for (x = 0; x < softwareRenderer->masterEnd; ++x) {
+		row[x] = softwareRenderer->row[x];
+	}
+#endif
+#else
+	memcpy(row, softwareRenderer->row, softwareRenderer->masterEnd * sizeof(*row));
+#endif
+}
+
 static void _drawScanlineA(struct DSVideoSoftwareRenderer* softwareRenderer, int y) {
 	memcpy(softwareRenderer->engA.d.vramBG, softwareRenderer->d.vramABG, sizeof(softwareRenderer->engA.d.vramBG));
 	memcpy(softwareRenderer->engA.d.vramOBJ, softwareRenderer->d.vramAOBJ, sizeof(softwareRenderer->engA.d.vramOBJ));
@@ -174,7 +348,7 @@ static void _drawScanlineA(struct DSVideoSoftwareRenderer* softwareRenderer, int
 		}
 		return;
 	case 1:
-		softwareRenderer->engA.d.drawScanline(&softwareRenderer->engA.d, y);
+		DSVideoSoftwareRendererDrawGBAScanline(&softwareRenderer->engA.d, y);
 		return;
 	case 2: {
 		uint16_t* vram = &softwareRenderer->d.vram[0x10000 * DSRegisterDISPCNTGetVRAMBlock(softwareRenderer->dispcntA)];
@@ -229,7 +403,7 @@ static void _drawScanlineB(struct DSVideoSoftwareRenderer* softwareRenderer, int
 		}
 		return;
 	case 1:
-		softwareRenderer->engB.d.drawScanline(&softwareRenderer->engB.d, y);
+		DSVideoSoftwareRendererDrawGBAScanline(&softwareRenderer->engB.d, y);
 		return;
 	}
 

src/ds/video.c

@@ -20,6 +20,7 @@ static void DSVideoDummyRendererDeinit(struct DSVideoRenderer* renderer);
 static uint16_t DSVideoDummyRendererWriteVideoRegister(struct DSVideoRenderer* renderer, uint32_t address, uint16_t value);
 static void DSVideoDummyRendererWritePalette(struct DSVideoRenderer* renderer, uint32_t address, uint16_t value);
 static void DSVideoDummyRendererWriteOAM(struct DSVideoRenderer* renderer, uint32_t oam);
+static void DSVideoDummyRendererInvalidateExtPal(struct DSVideoRenderer* renderer, bool obj, bool engB, int slot);
 static void DSVideoDummyRendererDrawScanline(struct DSVideoRenderer* renderer, int y);
 static void DSVideoDummyRendererFinishFrame(struct DSVideoRenderer* renderer);
 static void DSVideoDummyRendererGetPixels(struct DSVideoRenderer* renderer, size_t* stride, const void** pixels);
@@ -42,60 +43,86 @@ static const uint32_t _vramSize[9] = {
 	0x04000
 };
 
+enum DSVRAMBankMode {
+	MODE_A_BG = 0,
+	MODE_B_BG = 1,
+	MODE_A_OBJ = 2,
+	MODE_B_OBJ = 3,
+	MODE_LCDC,
+	MODE_7_VRAM,
+	MODE_A_BG_EXT_PAL,
+	MODE_B_BG_EXT_PAL,
+	MODE_A_OBJ_EXT_PAL,
+	MODE_B_OBJ_EXT_PAL,
+	MODE_3D_TEX,
+	MODE_3D_TEX_PAL,
+};
+
 const struct DSVRAMBankInfo {
 	int base;
 	uint32_t mirrorSize;
-	int mode;
+	enum DSVRAMBankMode mode;
 	int offset[4];
 } _vramInfo[9][8] = {
 	{ // A
-		{ 0x000, 0x40, 4 }, // LCDC
+		{ 0x000, 0x40, MODE_LCDC },
-		{ 0x000, 0x20, 0, { 0x00, 0x08, 0x10, 0x18 } }, // A-BG
+		{ 0x000, 0x20, MODE_A_BG, { 0x00, 0x08, 0x10, 0x18 } },
-		{ 0x000, 0x10, 2, { 0x00, 0x08, 0x80, 0x80 } }, // A-OBJ
+		{ 0x000, 0x10, MODE_A_OBJ, { 0x00, 0x08, 0x80, 0x80 } },
+		{ 0x000, 0x10, MODE_3D_TEX, { 0x00, 0x01, 0x02, 0x03 } },
 	},
 	{ // B
-		{ 0x008, 0x40, 4 }, // LCDC
+		{ 0x008, 0x40, MODE_LCDC },
-		{ 0x000, 0x20, 0, { 0x00, 0x08, 0x10, 0x18 } }, // A-BG
+		{ 0x000, 0x20, MODE_A_BG, { 0x00, 0x08, 0x10, 0x18 } },
-		{ 0x000, 0x10, 2, { 0x00, 0x08, 0x80, 0x80 } }, // A-OBJ
+		{ 0x000, 0x10, MODE_A_OBJ, { 0x00, 0x08, 0x80, 0x80 } },
+		{ 0x000, 0x10, MODE_3D_TEX, { 0x00, 0x01, 0x02, 0x03 } },
 	},
 	{ // C
-		{ 0x010, 0x40, 4 }, // LCDC
+		{ 0x010, 0x40, MODE_LCDC },
-		{ 0x000, 0x20, 0, { 0x00, 0x08, 0x10, 0x18 } }, // A-BG
+		{ 0x000, 0x20, MODE_A_BG, { 0x00, 0x08, 0x10, 0x18 } },
-		{ 0x000, 0x40, 5, { 0x00, 0x08, 0x80, 0x80 } }, // 7-VRAM
+		{ 0x000, 0x40, MODE_7_VRAM, { 0x00, 0x08, 0x80, 0x80 } },
-		{},
+		{ 0x000, 0x10, MODE_3D_TEX, { 0x00, 0x01, 0x02, 0x03 } },
-		{ 0x000, 0x08, 1 }, // B-BG
+		{ 0x000, 0x08, MODE_B_BG },
 	},
 	{ // D
-		{ 0x018, 0x40, 4 }, // LCDC
+		{ 0x018, 0x40, MODE_LCDC },
-		{ 0x000, 0x20, 0, { 0x00, 0x08, 0x10, 0x18 } }, // A-BG
+		{ 0x000, 0x20, MODE_A_BG, { 0x00, 0x08, 0x10, 0x18 } },
-		{ 0x000, 0x40, 8, { 0x00, 0x08, 0x80, 0x80 } }, // 7-VRAM
+		{ 0x000, 0x40, MODE_7_VRAM, { 0x00, 0x08, 0x80, 0x80 } },
-		{},
+		{ 0x000, 0x10, MODE_3D_TEX, { 0x00, 0x01, 0x02, 0x03 } },
-		{ 0x000, 0x08, 3 }, // B-OBJ
+		{ 0x000, 0x08, MODE_B_OBJ },
 	},
 	{ // E
-		{ 0x020, 0x40, 4 }, // LCDC
+		{ 0x020, 0x40, MODE_LCDC },
-		{ 0x000, 0x20, 0 }, // A-BG
+		{ 0x000, 0x20, MODE_A_BG },
-		{ 0x000, 0x10, 2 }, // A-OBJ
+		{ 0x000, 0x10, MODE_A_OBJ },
+		{ 0x000, 0x04, MODE_3D_TEX_PAL },
+		{ 0x000, 0x04, MODE_A_BG_EXT_PAL },
 	},
 	{ // F
-		{ 0x024, 0x40, 4 }, // LCDC
+		{ 0x024, 0x40, MODE_LCDC },
-		{ 0x000, 0x20, 0, { 0x00, 0x01, 0x04, 0x05 } }, // A-BG
+		{ 0x000, 0x20, MODE_A_BG, { 0x00, 0x01, 0x04, 0x05 } },
-		{ 0x000, 0x10, 2, { 0x00, 0x01, 0x04, 0x05 } }, // A-OBJ
+		{ 0x000, 0x10, MODE_A_OBJ, { 0x00, 0x01, 0x04, 0x05 } },
+		{ 0x000, 0x01, MODE_3D_TEX_PAL, { 0x00, 0x01, 0x04, 0x05 } },
+		{ 0x000, 0x02, MODE_A_BG_EXT_PAL, { 0x00, 0x02, 0x00, 0x02 } },
+		{ 0x000, 0x01, MODE_A_OBJ_EXT_PAL},
 	},
 	{ // G
-		{ 0x025, 0x40, 4 }, // LCDC
+		{ 0x025, 0x40, MODE_LCDC },
-		{ 0x000, 0x20, 0 }, // A-BG
+		{ 0x000, 0x20, MODE_A_BG, { 0x00, 0x01, 0x04, 0x05 } },
-		{ 0x000, 0x10, 2 }, // A-OBJ
+		{ 0x000, 0x10, MODE_A_OBJ, { 0x00, 0x01, 0x04, 0x05 } },
+		{ 0x000, 0x01, MODE_3D_TEX_PAL, { 0x00, 0x01, 0x04, 0x05 } },
+		{ 0x000, 0x02, MODE_A_BG_EXT_PAL, { 0x00, 0x02, 0x00, 0x02 } },
+		{ 0x000, 0x01, MODE_A_OBJ_EXT_PAL},
 	},
 	{ // H
-		{ 0x026, 0x40, 4 }, // LCDC
+		{ 0x026, 0x40, MODE_LCDC },
-		{ 0x000, 0x04, 1 }, // B-BG
+		{ 0x000, 0x04, MODE_B_BG },
-		{ 0x000, 0x10, 2 }, // A-OBJ
+		{ 0x000, 0x04, MODE_B_BG_EXT_PAL },
 	},
 	{ // I
-		{ 0x028, 0x40, 4 }, // LCDC
+		{ 0x028, 0x40, MODE_LCDC },
-		{ 0x002, 0x04, 1 }, // B-BG
+		{ 0x002, 0x04, MODE_B_BG },
-		{ 0x000, 0x01, 3 }, // B-OBJ
+		{ 0x000, 0x01, MODE_B_OBJ },
+		{ 0x000, 0x01, MODE_B_OBJ_EXT_PAL },
 	},
 };
 
@@ -166,8 +193,12 @@ void DSVideoAssociateRenderer(struct DSVideo* video, struct DSVideoRenderer* ren
 	renderer->vram = video->vram;
 	memcpy(renderer->vramABG, video->vramABG, sizeof(renderer->vramABG));
 	memcpy(renderer->vramAOBJ, video->vramAOBJ, sizeof(renderer->vramAOBJ));
+	memcpy(renderer->vramABGExtPal, video->vramABGExtPal, sizeof(renderer->vramABGExtPal));
+	memcpy(renderer->vramAOBJExtPal, video->vramAOBJExtPal, sizeof(renderer->vramAOBJExtPal));
 	memcpy(renderer->vramBBG, video->vramBBG, sizeof(renderer->vramBBG));
 	memcpy(renderer->vramBOBJ, video->vramBOBJ, sizeof(renderer->vramBOBJ));
+	memcpy(renderer->vramBBGExtPal, video->vramBBGExtPal, sizeof(renderer->vramBBGExtPal));
+	memcpy(renderer->vramBOBJExtPal, video->vramBOBJExtPal, sizeof(renderer->vramBOBJExtPal));
 	renderer->oam = &video->oam;
 	video->renderer->init(video->renderer);
 }
@@ -300,18 +331,83 @@ void DSVideoWriteDISPSTAT(struct DSCommon* dscore, uint16_t value) {
 	// TODO: Does a VCounter IRQ trigger on write?
 }
 
-void DSVideoConfigureVRAM(struct DS* ds, int index, uint8_t value) {
+void DSVideoConfigureVRAM(struct DS* ds, int index, uint8_t value, uint8_t oldValue) {
 	struct DSMemory* memory = &ds->memory;
+	if (value == oldValue) {
+		return;
+	}
+	uint32_t i, j;
+	uint32_t size = _vramSize[index] >> DS_VRAM_OFFSET;
+	struct DSVRAMBankInfo oldInfo = _vramInfo[index][oldValue & 0x7];
+	uint32_t offset = oldInfo.base + oldInfo.offset[(oldValue >> 3) & 3];
+	switch (oldInfo.mode) {
+	case MODE_A_BG:
+		for (i = 0; i < size; ++i) {
+			if (ds->video.vramABG[offset + i] == &memory->vramBank[index][i << (DS_VRAM_OFFSET - 1)]) {
+				ds->video.vramABG[offset + i] = NULL;
+				ds->video.renderer->vramABG[offset + i] = NULL;
+			}
+		}
+		break;
+	case MODE_B_BG:
+		for (i = 0; i < size; ++i) {
+			if (ds->video.vramBBG[offset + i] == &memory->vramBank[index][i << (DS_VRAM_OFFSET - 1)]) {
+				ds->video.vramBBG[offset + i] = NULL;
+				ds->video.renderer->vramBBG[offset + i] = NULL;
+			}
+		}
+		break;
+	case MODE_A_OBJ:
+		for (i = 0; i < size; ++i) {
+			if (ds->video.vramAOBJ[offset + i] == &memory->vramBank[index][i << (DS_VRAM_OFFSET - 1)]) {
+				ds->video.vramAOBJ[offset + i] = NULL;
+				ds->video.renderer->vramAOBJ[offset + i] = NULL;
+			}
+		}
+		break;
+	case MODE_B_OBJ:
+		for (i = 0; i < size; ++i) {
+			if (ds->video.vramBOBJ[offset + i] == &memory->vramBank[index][i << (DS_VRAM_OFFSET - 1)]) {
+				ds->video.vramBOBJ[offset + i] = NULL;
+				ds->video.renderer->vramBOBJ[offset + i] = NULL;
+			}
+		}
+		break;
+	case MODE_A_BG_EXT_PAL:
+		for (i = 0; i < oldInfo.mirrorSize; ++i) {
+			if (ds->video.vramABGExtPal[offset + i] == &memory->vramBank[index][i << 12]) {
+				ds->video.vramABGExtPal[offset + i] = NULL;
+				ds->video.renderer->vramABGExtPal[offset + i] = NULL;
+				ds->video.renderer->invalidateExtPal(ds->video.renderer, false, false, offset + i);
+			}
+		}
+		break;
+	case MODE_B_BG_EXT_PAL:
+		for (i = 0; i < oldInfo.mirrorSize; ++i) {
+			if (ds->video.vramBBGExtPal[offset + i] == &memory->vramBank[index][i << 12]) {
+				ds->video.vramBBGExtPal[offset + i] = NULL;
+				ds->video.renderer->vramBBGExtPal[offset + i] = NULL;
+				ds->video.renderer->invalidateExtPal(ds->video.renderer, false, true, offset + i);
+			}
+		}
+		break;
+	case MODE_7_VRAM:
+		for (i = 0; i < size; i += 16) {
+			ds->memory.vram7[(offset + i) >> 4] = NULL;
+		}
+		break;
+	case MODE_LCDC:
+		break;
+	}
+
 	struct DSVRAMBankInfo info = _vramInfo[index][value & 0x7];
 	memset(&memory->vramMirror[index], 0, sizeof(memory->vramMirror[index]));
 	memset(&memory->vramMode[index], 0, sizeof(memory->vramMode[index]));
 	if (!(value & 0x80) || !info.mirrorSize) {
 		return;
 	}
-	uint32_t size = _vramSize[index] >> DS_VRAM_OFFSET;
+	offset = info.base + info.offset[(value >> 3) & 3];
-	uint32_t i, j;
+	if (info.mode <= MODE_LCDC) {
-	uint32_t offset = info.base + info.offset[(value >> 3) & 3];
-	if (info.mode < 4) {
 		memory->vramMode[index][info.mode] = 0xFFFF;
 		for (j = offset; j < 0x40; j += info.mirrorSize) {
 			for (i = 0; i < size; ++i) {
@@ -320,35 +416,51 @@ void DSVideoConfigureVRAM(struct DS* ds, int index, uint8_t value) {
 		}
 	}
 	switch (info.mode) {
-	case 0:
+	case MODE_A_BG:
 		for (i = 0; i < size; ++i) {
 			ds->video.vramABG[offset + i] = &memory->vramBank[index][i << (DS_VRAM_OFFSET - 1)];
 			ds->video.renderer->vramABG[offset + i] = ds->video.vramABG[offset + i];
 		}
 		break;
-	case 1:
+	case MODE_B_BG:
 		for (i = 0; i < size; ++i) {
 			ds->video.vramBBG[offset + i] = &memory->vramBank[index][i << (DS_VRAM_OFFSET - 1)];
 			ds->video.renderer->vramBBG[offset + i] = ds->video.vramBBG[offset + i];
 		}
 		break;
-	case 2:
+	case MODE_A_OBJ:
 		for (i = 0; i < size; ++i) {
 			ds->video.vramAOBJ[offset + i] = &memory->vramBank[index][i << (DS_VRAM_OFFSET - 1)];
 			ds->video.renderer->vramAOBJ[offset + i] = ds->video.vramAOBJ[offset + i];
 		}
 		break;
-	case 3:
+	case MODE_B_OBJ:
 		for (i = 0; i < size; ++i) {
 			ds->video.vramBOBJ[offset + i] = &memory->vramBank[index][i << (DS_VRAM_OFFSET - 1)];
 			ds->video.renderer->vramBOBJ[offset + i] = ds->video.vramBOBJ[offset + i];
 		}
 		break;
-	case 5:
+	case MODE_A_BG_EXT_PAL:
+		for (i = 0; i < info.mirrorSize; ++i) {
+			ds->video.vramABGExtPal[offset + i] = &memory->vramBank[index][i << 12];
+			ds->video.renderer->vramABGExtPal[offset + i] = ds->video.vramABGExtPal[offset + i];
+			ds->video.renderer->invalidateExtPal(ds->video.renderer, false, false, offset + i);
+		}
+		break;
+	case MODE_B_BG_EXT_PAL:
+		for (i = 0; i < info.mirrorSize; ++i) {
+			ds->video.vramBBGExtPal[offset + i] = &memory->vramBank[index][i << 12];
+			ds->video.renderer->vramBBGExtPal[offset + i] = ds->video.vramBBGExtPal[offset + i];
+			ds->video.renderer->invalidateExtPal(ds->video.renderer, false, true, offset + i);
+		}
+		break;
+	case MODE_7_VRAM:
 		for (i = 0; i < size; i += 16) {
 			ds->memory.vram7[(offset + i) >> 4] = &memory->vramBank[index][i << (DS_VRAM_OFFSET - 5)];
 		}
 		break;
+	case MODE_LCDC:
+		break;
 	}
 }
 
@@ -385,6 +497,13 @@ static void DSVideoDummyRendererWriteOAM(struct DSVideoRenderer* renderer, uint3
 	// Nothing to do
 }
 
+static void DSVideoDummyRendererInvalidateExtPal(struct DSVideoRenderer* renderer, bool obj, bool engB, int slot) {
+	UNUSED(renderer);
+	UNUSED(obj);
+	UNUSED(engB);
+	// Nothing to do
+}
+
 static void DSVideoDummyRendererDrawScanline(struct DSVideoRenderer* renderer, int y) {
 	UNUSED(renderer);
 	UNUSED(y);

src/gba/renderers/software-mode0.c

@@ -15,6 +15,9 @@
 	} \
 	screenBase = background->screenBase + yBase + (xBase >> 2); \
 	uint16_t* screenBlock = renderer->d.vramBG[screenBase >> VRAM_BLOCK_OFFSET]; \
+	if (UNLIKELY(!screenBlock)) { \
+		return; \
+	} \
 	LOAD_16(mapData, screenBase & VRAM_BLOCK_MASK, screenBlock); \
 	localY = inY & 0x7; \
 	if (GBA_TEXT_MAP_VFLIP(mapData)) { \
@@ -361,6 +364,195 @@
 		} \
 	}
 
+#define DRAW_BACKGROUND_MODE_0_TILE_SUFFIX_256Ext(BLEND, OBJWIN) \
+	paletteData = GBA_TEXT_MAP_PALETTE(mapData) << 8; \
+	palette = &mainPalette[paletteData]; \
+	charBase = (background->charBase + (GBA_TEXT_MAP_TILE(mapData) << 6)) + (localY << 3); \
+	vram = renderer->d.vramBG[charBase >> VRAM_BLOCK_OFFSET]; \
+	int end2 = end - 4; \
+	if (!GBA_TEXT_MAP_HFLIP(mapData)) { \
+		int shift = inX & 0x3; \
+		if (LIKELY(vram)) { \
+			if (end2 > outX) { \
+				LOAD_32(tileData, charBase & VRAM_BLOCK_MASK, vram); \
+				tileData >>= 8 * shift; \
+				shift = 0; \
+				for (; outX < end2; ++outX, ++pixel) { \
+					BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 0); \
+				} \
+			} \
+		} \
+		\
+		if (LIKELY(vram)) { \
+			LOAD_32(tileData, (charBase + 4) & VRAM_BLOCK_MASK, vram); \
+			tileData >>= 8 * shift; \
+			for (; outX < end; ++outX, ++pixel) { \
+				BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 0); \
+			} \
+		} \
+	} else { \
+		int start = outX; \
+		outX = end - 1; \
+		pixel = &renderer->row[outX]; \
+		if (LIKELY(vram)) { \
+			if (end2 > start) { \
+				LOAD_32(tileData, charBase & VRAM_BLOCK_MASK, vram); \
+				for (; outX >= end2; --outX, --pixel) { \
+					BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 0); \
+				} \
+				charBase += 4; \
+			} \
+		} \
+		\
+		if (LIKELY(vram)) { \
+			LOAD_32(tileData, charBase, vram); \
+			for (; outX >= renderer->start; --outX, --pixel) { \
+				BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 0); \
+			} \
+		} \
+		outX = end; \
+		pixel = &renderer->row[outX]; \
+	}
+
+#define DRAW_BACKGROUND_MODE_0_TILE_PREFIX_256Ext(BLEND, OBJWIN) \
+	charBase = (background->charBase + (GBA_TEXT_MAP_TILE(mapData) << 6)) + (localY << 3); \
+	vram = renderer->d.vramBG[charBase >> VRAM_BLOCK_OFFSET]; \
+	if (UNLIKELY(!vram)) { \
+		return; \
+	} \
+	paletteData = GBA_TEXT_MAP_PALETTE(mapData) << 8; \
+	palette = &mainPalette[paletteData]; \
+	int end = mod8 - 4; \
+	pixel = &renderer->row[outX]; \
+	if (!GBA_TEXT_MAP_HFLIP(mapData)) { \
+		if (end > 0) { \
+			LOAD_32(tileData, charBase & VRAM_BLOCK_MASK, vram); \
+			for (; outX < renderer->end - end; ++outX, ++pixel) { \
+				BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 0); \
+			} \
+			charBase += 4; \
+		} \
+		\
+		LOAD_32(tileData, charBase & VRAM_BLOCK_MASK, vram); \
+		for (; outX < renderer->end; ++outX, ++pixel) { \
+			BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 0); \
+		} \
+	} else { \
+		int shift = (8 - mod8) & 0x3; \
+		int start = outX; \
+		outX = renderer->end - 1; \
+		pixel = &renderer->row[outX]; \
+		if (end > 0) { \
+			LOAD_32(tileData, charBase & VRAM_BLOCK_MASK, vram); \
+			tileData >>= 8 * shift; \
+			for (; outX >= start + 4; --outX, --pixel) { \
+				BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 0); \
+			} \
+			shift = 0; \
+		} \
+		\
+		LOAD_32(tileData, (charBase + 4) & VRAM_BLOCK_MASK, vram); \
+		tileData >>= 8 * shift; \
+		for (; outX >= start; --outX, --pixel) { \
+			BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 0); \
+		} \
+		/* Needed for consistency checks */ \
+		if (VIDEO_CHECKS) { \
+			outX = renderer->end; \
+			pixel = &renderer->row[outX]; \
+		} \
+	}
+
+#define DRAW_BACKGROUND_MODE_0_TILES_256Ext(BLEND, OBJWIN) \
+	for (; tileX < tileEnd; ++tileX) { \
+		BACKGROUND_TEXT_SELECT_CHARACTER; \
+		paletteData = GBA_TEXT_MAP_PALETTE(mapData) << 8; \
+		palette = &mainPalette[paletteData]; \
+		charBase = (background->charBase + (GBA_TEXT_MAP_TILE(mapData) << 6)) + (localY << 3); \
+		vram = renderer->d.vramBG[charBase >> VRAM_BLOCK_OFFSET]; \
+		if (UNLIKELY(!vram)) { \
+			pixel += 8; \
+			continue; \
+		} \
+		if (!GBA_TEXT_MAP_HFLIP(mapData)) { \
+			LOAD_32(tileData, charBase & VRAM_BLOCK_MASK, vram); \
+			if (tileData) { \
+					BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 0); \
+					BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 1); \
+					BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 2); \
+					BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 3); \
+			} \
+			pixel += 4; \
+			LOAD_32(tileData, (charBase + 4) & VRAM_BLOCK_MASK, vram); \
+			if (tileData) { \
+					BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 0); \
+					BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 1); \
+					BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 2); \
+					BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 3); \
+			} \
+			pixel += 4; \
+		} else { \
+			LOAD_32(tileData, (charBase + 4) & VRAM_BLOCK_MASK, vram); \
+			if (tileData) { \
+				BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 3); \
+				BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 2); \
+				BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 1); \
+				BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 0); \
+			} \
+			pixel += 4; \
+			LOAD_32(tileData, charBase & VRAM_BLOCK_MASK, vram); \
+			if (tileData) { \
+				BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 3); \
+				BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 2); \
+				BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 1); \
+				BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 0); \
+			} \
+			pixel += 4; \
+		} \
+	}
+
+#define DRAW_BACKGROUND_MODE_0_MOSAIC_256Ext(BLEND, OBJWIN) \
+	for (; tileX < tileEnd; ++tileX) { \
+		BACKGROUND_TEXT_SELECT_CHARACTER; \
+		charBase = (background->charBase + (GBA_TEXT_MAP_TILE(mapData) << 6)) + (localY << 3); \
+		vram = renderer->d.vramBG[charBase >> VRAM_BLOCK_OFFSET]; \
+		tileData = carryData; \
+		for (x = 0; x < 8; ++x) { \
+			if (!mosaicWait) { \
+				if (UNLIKELY(!vram)) { \
+					carryData = 0; \
+				} else { \
+					paletteData = GBA_TEXT_MAP_PALETTE(mapData) << 8; \
+					palette = &mainPalette[paletteData]; \
+					if (!GBA_TEXT_MAP_HFLIP(mapData)) { \
+						if (x >= 4) { \
+							LOAD_32(tileData, (charBase + 4) & VRAM_BLOCK_MASK, vram); \
+							tileData >>= (x - 4) * 8; \
+						} else { \
+							LOAD_32(tileData, charBase & VRAM_BLOCK_MASK, vram); \
+							tileData >>= x * 8; \
+						} \
+					} else { \
+						if (x >= 4) { \
+							LOAD_32(tileData, charBase & VRAM_BLOCK_MASK, vram); \
+							tileData >>= (7 - x) * 8; \
+						} else { \
+							LOAD_32(tileData, (charBase + 4) & VRAM_BLOCK_MASK, vram); \
+							tileData >>= (3 - x) * 8; \
+						} \
+					} \
+					tileData &= 0xFF; \
+					carryData = tileData; \
+				} \
+				mosaicWait = mosaicH; \
+			} \
+			tileData |= tileData << 8; \
+			--mosaicWait; \
+			BACKGROUND_DRAW_PIXEL_256(BLEND, OBJWIN, 0); \
+			++pixel; \
+		} \
+	}
+
 #define DRAW_BACKGROUND_MODE_0(BPP, BLEND, OBJWIN) \
 	uint32_t* pixel = &renderer->row[outX]; \
 	if (background->mosaic && GBAMosaicControlGetBgH(renderer->mosaic)) { \
@@ -460,10 +652,19 @@ void GBAVideoSoftwareRendererDrawBackgroundMode0(struct GBAVideoSoftwareRenderer
 	uint32_t screenBase;
 	uint32_t charBase;
 	int variant = background->target1 && GBAWindowControlIsBlendEnable(renderer->currentWindow.packed) && (renderer->blendEffect == BLEND_BRIGHTEN || renderer->blendEffect == BLEND_DARKEN);
-	color_t* mainPalette = renderer->normalPalette;
+	color_t* mainPalette;
+	if (background->multipalette && background->extPalette) {
+		mainPalette = background->extPalette;
+		// TODO
+		/*if (variant) {
+			mainPalette = background->variantPalette;
+		}*/
+	} else {
+		mainPalette = renderer->normalPalette;
 		if (variant) {
 			mainPalette = renderer->variantPalette;
 		}
+	}
 	color_t* palette = mainPalette;
 	PREPARE_OBJWIN;
 
@@ -481,28 +682,36 @@ void GBAVideoSoftwareRendererDrawBackgroundMode0(struct GBAVideoSoftwareRenderer
 		if (!(flags & FLAG_TARGET_2)) {
 			if (!background->multipalette) {
 				DRAW_BACKGROUND_MODE_0(16, NoBlend, NO_OBJWIN);
-			} else {
+			} else if (!background->extPalette) {
 				DRAW_BACKGROUND_MODE_0(256, NoBlend, NO_OBJWIN);
+			} else {
+				DRAW_BACKGROUND_MODE_0(256Ext, NoBlend, NO_OBJWIN);
 			}
 		} else {
 			if (!background->multipalette) {
 				DRAW_BACKGROUND_MODE_0(16, Blend, NO_OBJWIN);
-			} else {
+			} else if (!background->extPalette) {
 				DRAW_BACKGROUND_MODE_0(256, Blend, NO_OBJWIN);
+			} else {
+				DRAW_BACKGROUND_MODE_0(256Ext, Blend, NO_OBJWIN);
 			}
 		}
 	} else {
 		if (!(flags & FLAG_TARGET_2)) {
 			if (!background->multipalette) {
 				DRAW_BACKGROUND_MODE_0(16, NoBlend, OBJWIN);
-			} else {
+			} else if (!background->extPalette) {
 				DRAW_BACKGROUND_MODE_0(256, NoBlend, OBJWIN);
+			} else {
+				DRAW_BACKGROUND_MODE_0(256Ext, NoBlend, OBJWIN);
 			}
 		} else {
 			if (!background->multipalette) {
 				DRAW_BACKGROUND_MODE_0(16, Blend, OBJWIN);
-			} else {
+			} else if (!background->extPalette) {
 				DRAW_BACKGROUND_MODE_0(256, Blend, OBJWIN);
+			} else {
+				DRAW_BACKGROUND_MODE_0(256Ext, Blend, OBJWIN);
 			}
 		}
 	}

src/gba/renderers/video-software.c

@@ -135,6 +135,8 @@ static void GBAVideoSoftwareRendererReset(struct GBAVideoRenderer* renderer) {
 		bg->dmy = 256;
 		bg->sx = 0;
 		bg->sy = 0;
+		bg->extPalette = NULL;
+		bg->variantPalette = NULL;
 	}
 }