A include/mgba/internal/gba/renderers/gl.h

@@ -0,0 +1,103 @@
+/* Copyright (c) 2013-2019 Jeffrey Pfau
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * 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/. */
+#ifndef VIDEO_GL_H
+#define VIDEO_GL_H
+
+#include <mgba-util/common.h>
+
+CXX_GUARD_START
+
+#include <mgba/core/core.h>
+#include <mgba/gba/interface.h>
+#include <mgba/internal/gba/io.h>
+#include <mgba/internal/gba/video.h>
+
+#ifdef USE_EPOXY
+#include <epoxy/gl.h>
+#elif defined(BUILD_GL)
+#ifdef __APPLE__
+#include <OpenGL/gl3.h>
+#else
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glext.h>
+#endif
+#else
+#include <GLES2/gl2.h>
+#endif
+
+struct GBAVideoGLBackground {
+	GLuint fbo;
+	GLuint tex;
+	GLuint program;
+
+	unsigned index;
+	int enabled;
+	unsigned priority;
+	uint32_t charBase;
+	int mosaic;
+	int multipalette;
+	uint32_t screenBase;
+	int overflow;
+	int size;
+	int target1;
+	int target2;
+	uint16_t x;
+	uint16_t y;
+	int32_t refx;
+	int32_t refy;
+	int16_t dx;
+	int16_t dmx;
+	int16_t dy;
+	int16_t dmy;
+	int32_t sx;
+	int32_t sy;
+};
+
+struct GBAVideoGLRenderer {
+	struct GBAVideoRenderer d;
+
+	struct GBAVideoGLBackground bg[4];
+
+	GLuint fbo[2];
+	GLuint layers[2];
+
+	color_t* outputBuffer;
+	int outputBufferStride;
+
+	GLuint paletteTex;
+	bool paletteDirty;
+
+	GLuint oamTex;
+	bool oamDirty;
+
+	GLuint vramTex;
+	unsigned vramDirty;
+
+	GLuint bgPrograms[6];
+	GLuint objProgram;
+
+	GLuint compositeProgram;
+
+	GBARegisterDISPCNT dispcnt;
+
+	unsigned target1Obj;
+	unsigned target1Bd;
+	unsigned target2Obj;
+	unsigned target2Bd;
+	enum GBAVideoBlendEffect blendEffect;
+	uint16_t blda;
+	uint16_t bldb;
+	uint16_t bldy;
+
+	GBAMosaicControl mosaic;
+};
+
+void GBAVideoGLRendererCreate(struct GBAVideoGLRenderer* renderer);
+
+CXX_GUARD_END
+
+#endif

M src/gba/renderers/gl.c → src/gba/renderers/gl.c

@@ -22,33 +22,73 @@ static void GBAVideoGLRendererFinishFrame(struct GBAVideoRenderer* renderer);
 static void GBAVideoGLRendererGetPixels(struct GBAVideoRenderer* renderer, size_t* stride, const void** pixels);
 static void GBAVideoGLRendererPutPixels(struct GBAVideoRenderer* renderer, size_t stride, const void* pixels);
 
+static void GBAVideoGLRendererUpdateDISPCNT(struct GBAVideoGLRenderer* renderer);
+static void GBAVideoGLRendererWriteBGCNT(struct GBAVideoGLBackground* bg, uint16_t value);
+static void GBAVideoGLRendererWriteBGX_LO(struct GBAVideoGLBackground* bg, uint16_t value);
+static void GBAVideoGLRendererWriteBGX_HI(struct GBAVideoGLBackground* bg, uint16_t value);
+static void GBAVideoGLRendererWriteBGY_LO(struct GBAVideoGLBackground* bg, uint16_t value);
+static void GBAVideoGLRendererWriteBGY_HI(struct GBAVideoGLBackground* bg, uint16_t value);
+static void GBAVideoGLRendererWriteBLDCNT(struct GBAVideoGLRenderer* renderer, uint16_t value);
+
 static const GLchar* const _gl3Header =
-	"#version 120\n";
+	"#version 130\n";
 
 static const char* const _vertexShader =
-	"attribute vec4 position;\n"
+	"attribute vec2 position;\n"
+	"uniform int y;\n"
+	"const ivec2 maxPos = ivec2(240, 160);\n"
 	"varying vec2 texCoord;\n"
 
 	"void main() {\n"
-	"	gl_Position = position;\n"
-	"	texCoord = (position.st + vec2(1.0, -1.0)) * vec2(0.5, 0.5);\n"
+	"	vec2 local = (position + vec2(0, y)) / vec2(1., maxPos.y);\n"
+	"	gl_Position = vec4(local * 2. - 1., 0., 1.);\n"
+	"	texCoord = local * maxPos;\n"
 	"}";
 
-static const char* const _fragmentShader =
+static const char* const _renderTile16 =
+	"vec4 renderTile(int tile, int tileBase, int paletteId, ivec2 localCoord) {\n"
+	"	int address = tileBase + tile * 16 + (localCoord.x >> 2) + (localCoord.y << 1);\n"
+	"	vec4 halfrow = texelFetch(vram, ivec2(address & 255, address >> 8), 0);\n"
+	"	int entry = int(halfrow[3 - (localCoord.x & 3)] * 16.);\n"
+	"	vec4 color = texelFetch(palette, ivec2(entry, paletteId), 0);\n"
+	"	if (entry > 0) {\n"
+	"		color.a = 1.;\n"
+	"	} else {\n"
+	"		color.a = 0.;\n"
+	"	}\n"
+	"	return color;\n"
+	"}";
+
+static const char* const _renderMode0 =
 	"varying vec2 texCoord;\n"
-	"uniform sampler2D tex;\n"
+	"uniform sampler2D vram;\n"
+	"uniform sampler2D palette;\n"
+	"uniform int screenBase;\n"
+	"uniform int charBase;\n"
+	"uniform ivec2 offset;\n"
+
+	"vec4 renderTile(int tile, int tileBase, int paletteId, ivec2 localCoord);\n"
 
 	"void main() {\n"
-	"	vec4 color = texture2D(tex, texCoord);\n"
-	"	color.a = 1.;\n"
-	"	gl_FragColor = color;\n"
+	"	ivec2 coord = ivec2(texCoord) + offset;\n"
+	"	int mapAddress = screenBase + (coord.x >> 3) + (coord.y >> 3) * 32;\n"
+	"	vec4 map = texelFetch(vram, ivec2(mapAddress & 255, mapAddress >> 8), 0);\n"
+	"	int flags = int(map.g * 15.9);\n"
+	"	if ((flags & 4) == 4) {\n"
+	"		coord.x ^= 7;\n"
+	"	}\n"
+	"	if ((flags & 8) == 8) {\n"
+	"		coord.y ^= 7;\n"
+	"	}\n"
+	"	int tile = int(map.a * 15.9) + int(map.b * 15.9) * 16 + (flags & 0x3) * 256;\n"
+	"	gl_FragColor = renderTile(tile, charBase, int(map.r * 15.9), coord & 7);\n"
 	"}";
 
-static const GLfloat _vertices[] = {
-	-1.f, -1.f,
-	-1.f, 1.f,
-	1.f, 1.f,
-	1.f, -1.f,
+static const GLint _vertices[] = {
+	0, 0,
+	0, 1,
+	1, 1,
+	1, 0,
 };
 
 void GBAVideoGLRendererCreate(struct GBAVideoGLRenderer* renderer) {
@@ -73,12 +113,18 @@ }
 
 void GBAVideoGLRendererInit(struct GBAVideoRenderer* renderer) {
 	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
-	glGenFramebuffers(6, glRenderer->fbo);
-	glGenTextures(6, glRenderer->layers);
+	glGenFramebuffers(2, glRenderer->fbo);
+	glGenTextures(2, glRenderer->layers);
 
 	glGenTextures(1, &glRenderer->paletteTex);
 
 	glBindTexture(GL_TEXTURE_2D, glRenderer->paletteTex);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+	glGenTextures(1, &glRenderer->vramTex);
+
+	glBindTexture(GL_TEXTURE_2D, glRenderer->vramTex);
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 
@@ -87,34 +133,37 @@ }
 
 void GBAVideoGLRendererDeinit(struct GBAVideoRenderer* renderer) {
 	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
-	glDeleteFramebuffers(6, glRenderer->fbo);
-	glDeleteTextures(6, glRenderer->layers);
+	glDeleteFramebuffers(2, glRenderer->fbo);
+	glDeleteTextures(2, glRenderer->layers);
 	glDeleteTextures(1, &glRenderer->paletteTex);
+	glDeleteTextures(1, &glRenderer->vramTex);
+	glDeleteTextures(1, &glRenderer->oamTex);
 }
 
 void GBAVideoGLRendererReset(struct GBAVideoRenderer* renderer) {
 	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
-	glBindFramebuffer(GL_FRAMEBUFFER, glRenderer->fbo[5]);
-	glBindTexture(GL_TEXTURE_2D, glRenderer->layers[5]);
+	glBindFramebuffer(GL_FRAMEBUFFER, glRenderer->fbo[1]);
+	glBindTexture(GL_TEXTURE_2D, glRenderer->layers[1]);
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, GBA_VIDEO_HORIZONTAL_PIXELS, GBA_VIDEO_VERTICAL_PIXELS, 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
-	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, glRenderer->layers[5], 0);
+	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, glRenderer->layers[1], 0);
 	glBindFramebuffer(GL_FRAMEBUFFER, 0);
 
 	glRenderer->compositeProgram = glCreateProgram();
 	GLuint vs = glCreateShader(GL_VERTEX_SHADER);
 	GLuint fs = glCreateShader(GL_FRAGMENT_SHADER);
 
-	const GLchar* shaderBuffer[2];
+	const GLchar* shaderBuffer[3];
 	const GLubyte* version = glGetString(GL_VERSION);
 	shaderBuffer[0] = _gl3Header;
 	shaderBuffer[1] = _vertexShader;
 	glShaderSource(vs, 2, shaderBuffer, 0);
-	shaderBuffer[1] = _fragmentShader;
-	glShaderSource(fs, 2, shaderBuffer, 0);
+	shaderBuffer[1] = _renderMode0;
+	shaderBuffer[2] = _renderTile16;
+	glShaderSource(fs, 3, shaderBuffer, 0);
 
 	glAttachShader(glRenderer->compositeProgram, vs);
 	glAttachShader(glRenderer->compositeProgram, fs);
@@ -122,46 +171,294 @@ char log[1024];
 
 	glCompileShader(fs);
 	glGetShaderInfoLog(fs, 1024, 0, log);
+	if (log[0]) {
+		mLOG(GBA_VIDEO, ERROR, "Fragment shader compilation failure: %s", log);
+	}
 
 	glCompileShader(vs);
 	glGetShaderInfoLog(vs, 1024, 0, log);
+	if (log[0]) {
+		mLOG(GBA_VIDEO, ERROR, "Vertex shader compilation failure: %s", log);
+	}
 
 	glLinkProgram(glRenderer->compositeProgram);
 	glGetProgramInfoLog(glRenderer->compositeProgram, 1024, 0, log);
+	if (log[0]) {
+		mLOG(GBA_VIDEO, ERROR, "Program link failure: %s", log);
+	}
 
-	glRenderer->paletteDirty = false;
+	glRenderer->paletteDirty = true;
+	glRenderer->vramDirty = 0xFFFFFF;
+
+	glBindTexture(GL_TEXTURE_2D, glRenderer->vramTex);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA4, 256, 192, 0, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, 0);
 }
 
 void GBAVideoGLRendererWriteVRAM(struct GBAVideoRenderer* renderer, uint32_t address) {
-
+	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
+	glRenderer->vramDirty |= 1 << (address >> 12);
 }
 
 void GBAVideoGLRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam) {
-
+	UNUSED(oam);
+	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
+	glRenderer->oamDirty = true;
 }
 
 void GBAVideoGLRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
+	UNUSED(address);
+	UNUSED(value);
 	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
 	glRenderer->paletteDirty = true;
 }
 
 uint16_t GBAVideoGLRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
+	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
+	if (renderer->cache) {
+		GBAVideoCacheWriteVideoRegister(renderer->cache, address, value);
+	}
 
+	switch (address) {
+	case REG_DISPCNT:
+		value &= 0xFFF7;
+		glRenderer->dispcnt = value;
+		//GBAVideoGLRendererUpdateDISPCNT(glRenderer);
+		break;
+	case REG_BG0CNT:
+		value &= 0xDFFF;
+		GBAVideoGLRendererWriteBGCNT(&glRenderer->bg[0], value);
+		//GBAVideoGLRendererUpdateDISPCNT(glRenderer);
+		break;
+	case REG_BG1CNT:
+		value &= 0xDFFF;
+		GBAVideoGLRendererWriteBGCNT(&glRenderer->bg[1], value);
+		//GBAVideoGLRendererUpdateDISPCNT(glRenderer);
+		break;
+	case REG_BG2CNT:
+		value &= 0xFFFF;
+		GBAVideoGLRendererWriteBGCNT(&glRenderer->bg[2], value);
+		//GBAVideoGLRendererUpdateDISPCNT(glRenderer);
+		break;
+	case REG_BG3CNT:
+		value &= 0xFFFF;
+		GBAVideoGLRendererWriteBGCNT(&glRenderer->bg[3], value);
+		//GBAVideoGLRendererUpdateDISPCNT(glRenderer);
+		break;
+	case REG_BG0HOFS:
+		value &= 0x01FF;
+		glRenderer->bg[0].x = value;
+		break;
+	case REG_BG0VOFS:
+		value &= 0x01FF;
+		glRenderer->bg[0].y = value;
+		break;
+	case REG_BG1HOFS:
+		value &= 0x01FF;
+		glRenderer->bg[1].x = value;
+		break;
+	case REG_BG1VOFS:
+		value &= 0x01FF;
+		glRenderer->bg[1].y = value;
+		break;
+	case REG_BG2HOFS:
+		value &= 0x01FF;
+		glRenderer->bg[2].x = value;
+		break;
+	case REG_BG2VOFS:
+		value &= 0x01FF;
+		glRenderer->bg[2].y = value;
+		break;
+	case REG_BG3HOFS:
+		value &= 0x01FF;
+		glRenderer->bg[3].x = value;
+		break;
+	case REG_BG3VOFS:
+		value &= 0x01FF;
+		glRenderer->bg[3].y = value;
+		break;
+	case REG_BG2PA:
+		glRenderer->bg[2].dx = value;
+		break;
+	case REG_BG2PB:
+		glRenderer->bg[2].dmx = value;
+		break;
+	case REG_BG2PC:
+		glRenderer->bg[2].dy = value;
+		break;
+	case REG_BG2PD:
+		glRenderer->bg[2].dmy = value;
+		break;
+	case REG_BG2X_LO:
+		GBAVideoGLRendererWriteBGX_LO(&glRenderer->bg[2], value);
+		break;
+	case REG_BG2X_HI:
+		GBAVideoGLRendererWriteBGX_HI(&glRenderer->bg[2], value);
+		break;
+	case REG_BG2Y_LO:
+		GBAVideoGLRendererWriteBGY_LO(&glRenderer->bg[2], value);
+		break;
+	case REG_BG2Y_HI:
+		GBAVideoGLRendererWriteBGY_HI(&glRenderer->bg[2], value);
+		break;
+	case REG_BG3PA:
+		glRenderer->bg[3].dx = value;
+		break;
+	case REG_BG3PB:
+		glRenderer->bg[3].dmx = value;
+		break;
+	case REG_BG3PC:
+		glRenderer->bg[3].dy = value;
+		break;
+	case REG_BG3PD:
+		glRenderer->bg[3].dmy = value;
+		break;
+	case REG_BG3X_LO:
+		GBAVideoGLRendererWriteBGX_LO(&glRenderer->bg[3], value);
+		break;
+	case REG_BG3X_HI:
+		GBAVideoGLRendererWriteBGX_HI(&glRenderer->bg[3], value);
+		break;
+	case REG_BG3Y_LO:
+		GBAVideoGLRendererWriteBGY_LO(&glRenderer->bg[3], value);
+		break;
+	case REG_BG3Y_HI:
+		GBAVideoGLRendererWriteBGY_HI(&glRenderer->bg[3], value);
+		break;
+	case REG_BLDCNT:
+		GBAVideoGLRendererWriteBLDCNT(glRenderer, value);
+		value &= 0x3FFF;
+		break;
+	case REG_BLDALPHA:
+		glRenderer->blda = value & 0x1F;
+		if (glRenderer->blda > 0x10) {
+			glRenderer->blda = 0x10;
+		}
+		glRenderer->bldb = (value >> 8) & 0x1F;
+		if (glRenderer->bldb > 0x10) {
+			glRenderer->bldb = 0x10;
+		}
+		value &= 0x1F1F;
+		break;
+	case REG_BLDY:
+		value &= 0x1F;
+		if (value > 0x10) {
+			value = 0x10;
+		}
+		if (glRenderer->bldy != value) {
+			glRenderer->bldy = value;
+		}
+		break;
+	case REG_WIN0H:
+		/*glRenderer->winN[0].h.end = value;
+		glRenderer->winN[0].h.start = value >> 8;
+		if (glRenderer->winN[0].h.start > GBA_VIDEO_HORIZONTAL_PIXELS && glRenderer->winN[0].h.start > glRenderer->winN[0].h.end) {
+			glRenderer->winN[0].h.start = 0;
+		}
+		if (glRenderer->winN[0].h.end > GBA_VIDEO_HORIZONTAL_PIXELS) {
+			glRenderer->winN[0].h.end = GBA_VIDEO_HORIZONTAL_PIXELS;
+			if (glRenderer->winN[0].h.start > GBA_VIDEO_HORIZONTAL_PIXELS) {
+				glRenderer->winN[0].h.start = GBA_VIDEO_HORIZONTAL_PIXELS;
+			}
+		}*/
+		break;
+	case REG_WIN1H:
+		/*glRenderer->winN[1].h.end = value;
+		glRenderer->winN[1].h.start = value >> 8;
+		if (glRenderer->winN[1].h.start > GBA_VIDEO_HORIZONTAL_PIXELS && glRenderer->winN[1].h.start > glRenderer->winN[1].h.end) {
+			glRenderer->winN[1].h.start = 0;
+		}
+		if (glRenderer->winN[1].h.end > GBA_VIDEO_HORIZONTAL_PIXELS) {
+			glRenderer->winN[1].h.end = GBA_VIDEO_HORIZONTAL_PIXELS;
+			if (glRenderer->winN[1].h.start > GBA_VIDEO_HORIZONTAL_PIXELS) {
+				glRenderer->winN[1].h.start = GBA_VIDEO_HORIZONTAL_PIXELS;
+			}
+		}*/
+		break;
+	case REG_WIN0V:
+		/*glRenderer->winN[0].v.end = value;
+		glRenderer->winN[0].v.start = value >> 8;
+		if (glRenderer->winN[0].v.start > GBA_VIDEO_VERTICAL_PIXELS && glRenderer->winN[0].v.start > glRenderer->winN[0].v.end) {
+			glRenderer->winN[0].v.start = 0;
+		}
+		if (glRenderer->winN[0].v.end > GBA_VIDEO_VERTICAL_PIXELS) {
+			glRenderer->winN[0].v.end = GBA_VIDEO_VERTICAL_PIXELS;
+			if (glRenderer->winN[0].v.start > GBA_VIDEO_VERTICAL_PIXELS) {
+				glRenderer->winN[0].v.start = GBA_VIDEO_VERTICAL_PIXELS;
+			}
+		}*/
+		break;
+	case REG_WIN1V:
+		/*glRenderer->winN[1].v.end = value;
+		glRenderer->winN[1].v.start = value >> 8;
+		if (glRenderer->winN[1].v.start > GBA_VIDEO_VERTICAL_PIXELS && glRenderer->winN[1].v.start > glRenderer->winN[1].v.end) {
+			glRenderer->winN[1].v.start = 0;
+		}
+		if (glRenderer->winN[1].v.end > GBA_VIDEO_VERTICAL_PIXELS) {
+			glRenderer->winN[1].v.end = GBA_VIDEO_VERTICAL_PIXELS;
+			if (glRenderer->winN[1].v.start > GBA_VIDEO_VERTICAL_PIXELS) {
+				glRenderer->winN[1].v.start = GBA_VIDEO_VERTICAL_PIXELS;
+			}
+		}*/
+		break;
+	case REG_WININ:
+		value &= 0x3F3F;
+		//glRenderer->winN[0].control.packed = value;
+		//glRenderer->winN[1].control.packed = value >> 8;
+		break;
+	case REG_WINOUT:
+		value &= 0x3F3F;
+		//glRenderer->winout.packed = value;
+		//glRenderer->objwin.packed = value >> 8;
+		break;
+	case REG_MOSAIC:
+		glRenderer->mosaic = value;
+		break;
+	case REG_GREENSWP:
+		mLOG(GBA_VIDEO, STUB, "Stub video register write: 0x%03X", address);
+		break;
+	default:
+		mLOG(GBA_VIDEO, GAME_ERROR, "Invalid video register: 0x%03X", address);
+	}
+	return value;
 }
 
 void GBAVideoGLRendererDrawScanline(struct GBAVideoRenderer* renderer, int y) {
 	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
 	if (glRenderer->paletteDirty) {
 		glBindTexture(GL_TEXTURE_2D, glRenderer->paletteTex);
-		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB5_A1, 256, 2, 0, GL_RGBA, GL_UNSIGNED_SHORT_1_5_5_5_REV, glRenderer->d.palette);
+		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB5_A1, 16, 32, 0, GL_RGBA, GL_UNSIGNED_SHORT_1_5_5_5_REV, glRenderer->d.palette);
 		glRenderer->paletteDirty = false;
 	}
-	glBindFramebuffer(GL_FRAMEBUFFER, glRenderer->fbo[5]);
+	if (glRenderer->oamDirty) {
+		glBindTexture(GL_TEXTURE_2D, glRenderer->oamTex);
+		glTexImage2D(GL_TEXTURE_2D, 0, GL_R16UI, 4, 128, 0, GL_RED_INTEGER, GL_UNSIGNED_SHORT, glRenderer->d.oam);
+		glRenderer->oamDirty = false;
+	}
+	int i;
+	for (i = 0; i < 24; ++i) {
+		if (!(glRenderer->vramDirty & (1 << i))) {
+			continue;
+		}
+		// TODO: PBOs
+		glBindTexture(GL_TEXTURE_2D, glRenderer->vramTex);
+		glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 8 * i, 256, 8, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, &glRenderer->d.vram[2048 * i]);
+	}
+	glRenderer->vramDirty = 0;
+
+	glBindFramebuffer(GL_FRAMEBUFFER, glRenderer->fbo[1]);
 	glViewport(0, 0, GBA_VIDEO_HORIZONTAL_PIXELS, GBA_VIDEO_VERTICAL_PIXELS);
 	glUseProgram(glRenderer->compositeProgram);
+	glActiveTexture(GL_TEXTURE0);
+	glBindTexture(GL_TEXTURE_2D, glRenderer->vramTex);
+	glActiveTexture(GL_TEXTURE0 + 1);
 	glBindTexture(GL_TEXTURE_2D, glRenderer->paletteTex);
-	glUniform1i(0, 0);
-	glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, _vertices);
+	glUniform1i(0, y);
+	glUniform1i(1, 0);
+	glUniform1i(2, 1);
+	glUniform1i(3, glRenderer->bg[0].screenBase);
+	glUniform1i(4, glRenderer->bg[0].charBase);
+	glUniform2i(5, glRenderer->bg[0].x, glRenderer->bg[0].y);
+	glVertexAttribPointer(0, 2, GL_INT, GL_FALSE, 0, _vertices);
 	glEnableVertexAttribArray(0);
 
 	glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
@@ -171,7 +468,7 @@
 void GBAVideoGLRendererFinishFrame(struct GBAVideoRenderer* renderer) {
 	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
 	glFinish();
-	glBindFramebuffer(GL_FRAMEBUFFER, glRenderer->fbo[5]);
+	glBindFramebuffer(GL_FRAMEBUFFER, glRenderer->fbo[1]);
 	glPixelStorei(GL_PACK_ROW_LENGTH, glRenderer->outputBufferStride);
 	glReadPixels(0, 0, GBA_VIDEO_HORIZONTAL_PIXELS, GBA_VIDEO_VERTICAL_PIXELS, GL_RGBA, GL_UNSIGNED_BYTE, glRenderer->outputBuffer);
 	glClearColor(1.f, 1.f, 0.f, 1.f);
@@ -187,3 +484,53 @@ void GBAVideoGLRendererPutPixels(struct GBAVideoRenderer* renderer, size_t stride, const void* pixels) {
 
 }
 
+static void GBAVideoGLRendererWriteBGCNT(struct GBAVideoGLBackground* bg, uint16_t value) {
+	bg->priority = GBARegisterBGCNTGetPriority(value);
+	bg->charBase = GBARegisterBGCNTGetCharBase(value) << 13;
+	bg->mosaic = GBARegisterBGCNTGetMosaic(value);
+	bg->multipalette = GBARegisterBGCNTGet256Color(value);
+	bg->screenBase = GBARegisterBGCNTGetScreenBase(value) << 10;
+	bg->overflow = GBARegisterBGCNTGetOverflow(value);
+	bg->size = GBARegisterBGCNTGetSize(value);
+}
+
+static void GBAVideoGLRendererWriteBGX_LO(struct GBAVideoGLBackground* bg, uint16_t value) {
+	bg->refx = (bg->refx & 0xFFFF0000) | value;
+	bg->sx = bg->refx;
+}
+
+static void GBAVideoGLRendererWriteBGX_HI(struct GBAVideoGLBackground* bg, uint16_t value) {
+	bg->refx = (bg->refx & 0x0000FFFF) | (value << 16);
+	bg->refx <<= 4;
+	bg->refx >>= 4;
+	bg->sx = bg->refx;
+}
+
+static void GBAVideoGLRendererWriteBGY_LO(struct GBAVideoGLBackground* bg, uint16_t value) {
+	bg->refy = (bg->refy & 0xFFFF0000) | value;
+	bg->sy = bg->refy;
+}
+
+static void GBAVideoGLRendererWriteBGY_HI(struct GBAVideoGLBackground* bg, uint16_t value) {
+	bg->refy = (bg->refy & 0x0000FFFF) | (value << 16);
+	bg->refy <<= 4;
+	bg->refy >>= 4;
+	bg->sy = bg->refy;
+}
+
+static void GBAVideoGLRendererWriteBLDCNT(struct GBAVideoGLRenderer* renderer, uint16_t value) {
+	renderer->bg[0].target1 = GBARegisterBLDCNTGetTarget1Bg0(value);
+	renderer->bg[1].target1 = GBARegisterBLDCNTGetTarget1Bg1(value);
+	renderer->bg[2].target1 = GBARegisterBLDCNTGetTarget1Bg2(value);
+	renderer->bg[3].target1 = GBARegisterBLDCNTGetTarget1Bg3(value);
+	renderer->bg[0].target2 = GBARegisterBLDCNTGetTarget2Bg0(value);
+	renderer->bg[1].target2 = GBARegisterBLDCNTGetTarget2Bg1(value);
+	renderer->bg[2].target2 = GBARegisterBLDCNTGetTarget2Bg2(value);
+	renderer->bg[3].target2 = GBARegisterBLDCNTGetTarget2Bg3(value);
+
+	renderer->blendEffect = GBARegisterBLDCNTGetEffect(value);
+	renderer->target1Obj = GBARegisterBLDCNTGetTarget1Obj(value);
+	renderer->target1Bd = GBARegisterBLDCNTGetTarget1Bd(value);
+	renderer->target2Obj = GBARegisterBLDCNTGetTarget2Obj(value);
+	renderer->target2Bd = GBARegisterBLDCNTGetTarget2Bd(value);
+}