all repos — mgba @ 509c80abad8221564a0bfade571d868e9e8247af

mGBA Game Boy Advance Emulator

src/gba/renderers/gl.c (view raw)

   1/* Copyright (c) 2013-2019 Jeffrey Pfau
   2 *
   3 * This Source Code Form is subject to the terms of the Mozilla Public
   4 * License, v. 2.0. If a copy of the MPL was not distributed with this
   5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6#include <mgba/internal/gba/renderers/gl.h>
   7
   8#include <mgba/core/cache-set.h>
   9#include <mgba/internal/arm/macros.h>
  10#include <mgba/internal/gba/io.h>
  11#include <mgba/internal/gba/renderers/cache-set.h>
  12
  13static void GBAVideoGLRendererInit(struct GBAVideoRenderer* renderer);
  14static void GBAVideoGLRendererDeinit(struct GBAVideoRenderer* renderer);
  15static void GBAVideoGLRendererReset(struct GBAVideoRenderer* renderer);
  16static void GBAVideoGLRendererWriteVRAM(struct GBAVideoRenderer* renderer, uint32_t address);
  17static void GBAVideoGLRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam);
  18static void GBAVideoGLRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value);
  19static uint16_t GBAVideoGLRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value);
  20static void GBAVideoGLRendererDrawScanline(struct GBAVideoRenderer* renderer, int y);
  21static void GBAVideoGLRendererFinishFrame(struct GBAVideoRenderer* renderer);
  22static void GBAVideoGLRendererGetPixels(struct GBAVideoRenderer* renderer, size_t* stride, const void** pixels);
  23static void GBAVideoGLRendererPutPixels(struct GBAVideoRenderer* renderer, size_t stride, const void* pixels);
  24
  25static void GBAVideoGLRendererUpdateDISPCNT(struct GBAVideoGLRenderer* renderer);
  26static void GBAVideoGLRendererWriteBGCNT(struct GBAVideoGLBackground* bg, uint16_t value);
  27static void GBAVideoGLRendererWriteBGX_LO(struct GBAVideoGLBackground* bg, uint16_t value);
  28static void GBAVideoGLRendererWriteBGX_HI(struct GBAVideoGLBackground* bg, uint16_t value);
  29static void GBAVideoGLRendererWriteBGY_LO(struct GBAVideoGLBackground* bg, uint16_t value);
  30static void GBAVideoGLRendererWriteBGY_HI(struct GBAVideoGLBackground* bg, uint16_t value);
  31static void GBAVideoGLRendererWriteBLDCNT(struct GBAVideoGLRenderer* renderer, uint16_t value);
  32
  33static void GBAVideoGLRendererDrawSprite(struct GBAVideoGLRenderer* renderer, struct GBAObj* sprite, int y, int spriteY);
  34static void GBAVideoGLRendererDrawBackgroundMode0(struct GBAVideoGLRenderer* renderer, struct GBAVideoGLBackground* background, int y);
  35static void GBAVideoGLRendererDrawBackgroundMode2(struct GBAVideoGLRenderer* renderer, struct GBAVideoGLBackground* background, int y);
  36static void GBAVideoGLRendererDrawBackgroundMode3(struct GBAVideoGLRenderer* renderer, struct GBAVideoGLBackground* background, int y);
  37static void GBAVideoGLRendererDrawBackgroundMode4(struct GBAVideoGLRenderer* renderer, struct GBAVideoGLBackground* background, int y);
  38static void GBAVideoGLRendererDrawBackgroundMode5(struct GBAVideoGLRenderer* renderer, struct GBAVideoGLBackground* background, int y);
  39
  40static void _compositeLayer(struct GBAVideoGLRenderer* renderer, GLuint tex, GLuint flags, int y);
  41
  42#define TEST_LAYER_ENABLED(X) !renderer->disableBG[X] && glRenderer->bg[X].enabled == 4 && glRenderer->bg[X].priority == priority
  43
  44static const GLchar* const _gl3Header =
  45	"#version 130\n";
  46
  47static const char* const _vertexShader =
  48	"attribute vec2 position;\n"
  49	"uniform ivec2 loc;\n"
  50	"uniform ivec2 maxPos;\n"
  51	"varying vec2 texCoord;\n"
  52
  53	"void main() {\n"
  54	"	vec2 local = vec2(position.x, float(position.y * loc.x + loc.y) / abs(maxPos.y));\n"
  55	"	gl_Position = vec4((local * 2. - 1.) * sign(maxPos), 0., 1.);\n"
  56	"	texCoord = local * abs(maxPos);\n"
  57	"}";
  58
  59static const char* const _renderTile16 =
  60	"vec4 renderTile(int tile, int paletteId, ivec2 localCoord) {\n"
  61	"	int address = charBase + tile * 16 + (localCoord.x >> 2) + (localCoord.y << 1);\n"
  62	"	vec4 halfrow = texelFetch(vram, ivec2(address & 255, address >> 8), 0);\n"
  63	"	int entry = int(halfrow[3 - (localCoord.x & 3)] * 15.9);\n"
  64	"	vec4 color = texelFetch(palette, ivec2(entry, paletteId), 0);\n"
  65	"	if (entry == 0) {\n"
  66	"		discard;\n"
  67	"	}\n"
  68	"	color.a = 1;\n"
  69	"	return color;\n"
  70	"}";
  71
  72static const char* const _renderTile256 =
  73	"vec4 renderTile(int tile, int paletteId, ivec2 localCoord) {\n"
  74	"	int address = charBase + tile * 32 + (localCoord.x >> 1) + (localCoord.y << 2);\n"
  75	"	vec4 halfrow = texelFetch(vram, ivec2(address & 255, address >> 8), 0);\n"
  76	"	int entry = int(halfrow[3 - 2 * (localCoord.x & 1)] * 15.9);\n"
  77	"	int pal2 = int(halfrow[2 - 2 * (localCoord.x & 1)] * 15.9);\n"
  78	"	vec4 color = texelFetch(palette, ivec2(entry, pal2 + (paletteId & 16)), 0);\n"
  79	"	if ((pal2 | entry) == 0) {\n"
  80	"		discard;\n"
  81	"	}\n"
  82	"	color.a = 1.;\n"
  83	"	return color;\n"
  84	"}";
  85
  86static const char* const _renderMode0 =
  87	"varying vec2 texCoord;\n"
  88	"uniform sampler2D vram;\n"
  89	"uniform sampler2D palette;\n"
  90	"uniform int screenBase;\n"
  91	"uniform int charBase;\n"
  92	"uniform int size;\n"
  93	"uniform ivec2 offset;\n"
  94	"uniform ivec3 inflags;\n"
  95	"out vec4 color;\n"
  96	"out vec3 flags;\n"
  97	"const vec3 flagCoeff = vec3(32., 8., 4.);\n"
  98
  99	"vec4 renderTile(int tile, int paletteId, ivec2 localCoord);\n"
 100
 101	"void main() {\n"
 102	"	ivec2 coord = ivec2(texCoord) + offset;\n"
 103	"	if ((size & 1) == 1) {\n"
 104	"		coord.y += coord.x & 256;\n"
 105	"	}\n"
 106	"	coord.x &= 255;\n"
 107	"	int mapAddress = screenBase + (coord.x >> 3) + (coord.y >> 3) * 32;\n"
 108	"	vec4 map = texelFetch(vram, ivec2(mapAddress & 255, mapAddress >> 8), 0);\n"
 109	"	int tileFlags = int(map.g * 15.9);\n"
 110	"	if ((tileFlags & 4) == 4) {\n"
 111	"		coord.x ^= 7;\n"
 112	"	}\n"
 113	"	if ((tileFlags & 8) == 8) {\n"
 114	"		coord.y ^= 7;\n"
 115	"	}\n"
 116	"	int tile = int(map.a * 15.9) + int(map.b * 15.9) * 16 + (tileFlags & 0x3) * 256;\n"
 117	"	color = renderTile(tile, int(map.r * 15.9), coord & 7);\n"
 118	"	flags = inflags / flagCoeff;\n"
 119	"}";
 120
 121static const char* const _fetchTileOverflow =
 122	"vec4 fetchTile(ivec2 coord) {\n"
 123	"	int sizeAdjusted = (0x8000 << size) - 1;\n"
 124	"	coord &= sizeAdjusted;\n"
 125	"	return renderTile(coord);\n"
 126	"}";
 127
 128static const char* const _fetchTileNoOverflow =
 129	"vec4 fetchTile(ivec2 coord) {\n"
 130	"	int sizeAdjusted = (0x8000 << size) - 1;\n"
 131	"	ivec2 outerCoord = coord & ~sizeAdjusted;\n"
 132	"	if ((outerCoord.x | outerCoord.y) != 0) {\n"
 133	"		discard;\n"
 134	"	}\n"
 135	"	return renderTile(coord);\n"
 136	"}";
 137
 138static const char* const _renderMode2 =
 139	"varying vec2 texCoord;\n"
 140	"uniform sampler2D vram;\n"
 141	"uniform sampler2D palette;\n"
 142	"uniform int screenBase;\n"
 143	"uniform int charBase;\n"
 144	"uniform int size;\n"
 145	"uniform ivec3 inflags;\n"
 146	"uniform ivec2[4] offset;\n"
 147	"uniform ivec2[4] transform;\n"
 148	"out vec4 color;\n"
 149	"out vec3 flags;\n"
 150	"const vec3 flagCoeff = vec3(32., 8., 4.);\n"
 151	"precision highp float;\n"
 152	"precision highp int;\n"
 153
 154	"vec4 fetchTile(ivec2 coord);\n"
 155
 156	"vec4 renderTile(ivec2 coord) {\n"
 157	"	int map = (coord.x >> 11) + (((coord.y >> 7) & 0x7F0) << size);\n"
 158	"	int mapAddress = screenBase + (map >> 1);\n"
 159	"	vec4 twomaps = texelFetch(vram, ivec2(mapAddress & 255, mapAddress >> 8), 0);\n"
 160	"	int tile = int(twomaps[3 - 2 * (map & 1)] * 15.9) + int(twomaps[2 - 2 * (map & 1)] * 15.9) * 16;\n"
 161	"	int address = charBase + tile * 32 + ((coord.x >> 9) & 3) + ((coord.y >> 6) & 0x1C);\n"
 162	"	vec4 halfrow = texelFetch(vram, ivec2(address & 255, address >> 8), 0);\n"
 163	"	int entry = int(halfrow[3 - ((coord.x >> 7) & 2)] * 15.9);\n"
 164	"	int pal2 = int(halfrow[2 - ((coord.x >> 7) & 2)] * 15.9);\n"
 165	"	vec4 color = texelFetch(palette, ivec2(entry, pal2), 0);\n"
 166	"	if ((pal2 | entry) == 0) {\n"
 167	"		discard;\n"
 168	"	}\n"
 169	"	color.a = 1.;\n"
 170	"	return color;\n"
 171	"}\n"
 172
 173	"vec2 interpolate(ivec2 arr[4], float x) {\n"
 174	"	float x1m = 1. - x;\n"
 175	"	return x1m * x1m * x1m * arr[0] +"
 176		"  3 * x1m * x1m * x   * arr[1] +"
 177		"  3 * x1m * x   * x   * arr[2] +"
 178		"      x   * x   * x   * arr[3];\n"
 179	"}\n"
 180
 181	"void main() {\n"
 182	"	float y = fract(texCoord.y);\n"
 183	"	float lin = 0.5 - y / ceil(y) * 0.25;\n"
 184	"	vec2 mixedTransform = interpolate(transform, lin);\n"
 185	"	vec2 mixedOffset = interpolate(offset, lin);\n"
 186	"	color = fetchTile(ivec2(mixedTransform * texCoord.x + mixedOffset));\n"
 187	"	flags = inflags / flagCoeff;\n"
 188	"}";
 189
 190static const char* const _renderObj =
 191	"varying vec2 texCoord;\n"
 192	"uniform sampler2D vram;\n"
 193	"uniform sampler2D palette;\n"
 194	"uniform int charBase;\n"
 195	"uniform int stride;\n"
 196	"uniform int localPalette;\n"
 197	"uniform ivec3 inflags;\n"
 198	"uniform mat2x2 transform;\n"
 199	"uniform ivec4 dims;\n"
 200	"out vec4 color;\n"
 201	"out vec3 flags;\n"
 202	"const vec3 flagCoeff = vec3(32., 8., 4.);\n"
 203
 204	"vec4 renderTile(int tile, int paletteId, ivec2 localCoord);\n"
 205
 206	"void main() {\n"
 207	"	ivec2 coord = ivec2(transform * (texCoord - dims.zw / 2) + dims.xy / 2);\n"
 208	"	if ((coord & ~(dims.xy - 1)) != ivec2(0, 0)) {\n"
 209	"		discard;\n"
 210	"	}\n"
 211	"	color = renderTile((coord.x >> 3) + (coord.y >> 3) * stride, 16 + localPalette, coord & 7);\n"
 212	"	flags = inflags / flagCoeff;\n"
 213	"}";
 214
 215static const char* const _composite =
 216	"varying vec2 texCoord;\n"
 217	"uniform int scale;\n"
 218	"uniform vec3 blend;\n"
 219	"uniform sampler2D layer;\n"
 220	"uniform sampler2D layerFlags;\n"
 221	"uniform sampler2D oldLayer;\n"
 222	"uniform sampler2D oldFlags;\n"
 223	"out vec4 color;\n"
 224	"out vec3 flags;\n"
 225	"const vec3 flagCoeff = vec3(32., 8., 4.);\n"
 226
 227	"void main() {\n"
 228	"	vec4 pix = texelFetch(layer, ivec2(texCoord * scale), 0);\n"
 229	"	if (pix.a == 0) {\n"
 230	"		discard;\n"
 231	"	}\n"
 232	"	ivec3 inflags = ivec3(texelFetch(layerFlags, ivec2(texCoord * scale), 0).xyz * flagCoeff);\n"
 233	"	ivec3 oflags = ivec3(texelFetch(oldFlags, ivec2(texCoord * scale), 0).xyz * flagCoeff);\n"
 234	"	ivec3 outflags = ivec3(0, 0, 0);\n"
 235	"	if (inflags.x < oflags.x) {\n"
 236	"		outflags = inflags;\n"
 237	"		if (inflags.z == 1 && (inflags.y & 1) == 1 && (oflags.y & 2) == 2) {\n"
 238	"			vec4 oldpix = texelFetch(oldLayer, ivec2(texCoord * scale), 0);\n"
 239	"			pix *= blend.x;\n"
 240	"			pix += oldpix * blend.y;\n"
 241	"		}\n"
 242	"	} else {\n"
 243	"		outflags = oflags;\n"
 244	"		vec4 oldpix = texelFetch(oldLayer, ivec2(texCoord * scale), 0);\n"
 245	"		if (oflags.z == 1 && (oflags.y & 1) == 1 && (inflags.y & 2) == 2) {\n"
 246	"			pix *= blend.y;\n"
 247	"			pix += oldpix * blend.x;\n"
 248	"		} else {\n"
 249	"			pix = oldpix;\n"
 250	"		}\n"
 251	"	}\n"
 252	"	color = pix;\n"
 253	"	flags = outflags / flagCoeff;\n"
 254	"}";
 255
 256static const GLint _vertices[] = {
 257	0, 0,
 258	0, 1,
 259	1, 1,
 260	1, 0,
 261};
 262
 263void GBAVideoGLRendererCreate(struct GBAVideoGLRenderer* renderer) {
 264	renderer->d.init = GBAVideoGLRendererInit;
 265	renderer->d.reset = GBAVideoGLRendererReset;
 266	renderer->d.deinit = GBAVideoGLRendererDeinit;
 267	renderer->d.writeVideoRegister = GBAVideoGLRendererWriteVideoRegister;
 268	renderer->d.writeVRAM = GBAVideoGLRendererWriteVRAM;
 269	renderer->d.writeOAM = GBAVideoGLRendererWriteOAM;
 270	renderer->d.writePalette = GBAVideoGLRendererWritePalette;
 271	renderer->d.drawScanline = GBAVideoGLRendererDrawScanline;
 272	renderer->d.finishFrame = GBAVideoGLRendererFinishFrame;
 273	renderer->d.getPixels = GBAVideoGLRendererGetPixels;
 274	renderer->d.putPixels = GBAVideoGLRendererPutPixels;
 275
 276	renderer->d.disableBG[0] = false;
 277	renderer->d.disableBG[1] = false;
 278	renderer->d.disableBG[2] = false;
 279	renderer->d.disableBG[3] = false;
 280	renderer->d.disableOBJ = false;
 281
 282	renderer->scale = 1;
 283}
 284
 285void _compileShader(struct GBAVideoGLRenderer* glRenderer, GLuint program, const char** shaderBuffer, int shaderBufferLines, GLuint vs, char* log) {
 286	GLuint fs = glCreateShader(GL_FRAGMENT_SHADER);
 287	glAttachShader(program, vs);
 288	glAttachShader(program, fs);
 289	glShaderSource(fs, shaderBufferLines, shaderBuffer, 0);
 290	glCompileShader(fs);
 291	glGetShaderInfoLog(fs, 1024, 0, log);
 292	if (log[0]) {
 293		mLOG(GBA_VIDEO, ERROR, "Fragment shader compilation failure: %s", log);
 294	}
 295	glLinkProgram(program);
 296	glGetProgramInfoLog(program, 1024, 0, log);
 297	if (log[0]) {
 298		mLOG(GBA_VIDEO, ERROR, "Program link failure: %s", log);
 299	}
 300	glDeleteShader(fs);
 301	glBindFragDataLocation(program, 0, "color");
 302	glBindFragDataLocation(program, 1, "flags");
 303}
 304
 305void GBAVideoGLRendererInit(struct GBAVideoRenderer* renderer) {
 306	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
 307	glGenFramebuffers(2, glRenderer->fbo);
 308	glGenTextures(3, glRenderer->layers);
 309
 310	glGenTextures(1, &glRenderer->paletteTex);
 311	glBindTexture(GL_TEXTURE_2D, glRenderer->paletteTex);
 312	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 313	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 314
 315	glGenTextures(1, &glRenderer->vramTex);
 316	glBindTexture(GL_TEXTURE_2D, glRenderer->vramTex);
 317	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 318	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 319	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA4, 256, 192, 0, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, 0);
 320
 321	glGenTextures(1, &glRenderer->oamTex);
 322	glBindTexture(GL_TEXTURE_2D, glRenderer->oamTex);
 323	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 324	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 325
 326	glBindFramebuffer(GL_FRAMEBUFFER, glRenderer->fbo[GBA_GL_FBO_OBJ]);
 327	glBindTexture(GL_TEXTURE_2D, glRenderer->layers[GBA_GL_TEX_OBJ_COLOR]);
 328	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 329	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 330	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 331	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 332	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, GBA_VIDEO_HORIZONTAL_PIXELS * glRenderer->scale, GBA_VIDEO_VERTICAL_PIXELS * glRenderer->scale, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
 333	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, glRenderer->layers[GBA_GL_TEX_OBJ_COLOR], 0);
 334
 335	glBindTexture(GL_TEXTURE_2D, glRenderer->layers[GBA_GL_TEX_OBJ_FLAGS]);
 336	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 337	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 338	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 339	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 340	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, GBA_VIDEO_HORIZONTAL_PIXELS * glRenderer->scale, GBA_VIDEO_VERTICAL_PIXELS * glRenderer->scale, 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
 341	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, glRenderer->layers[GBA_GL_TEX_OBJ_FLAGS], 0);
 342
 343	glBindFramebuffer(GL_FRAMEBUFFER, glRenderer->fbo[GBA_GL_FBO_COMPOSITE]);
 344	glBindTexture(GL_TEXTURE_2D, glRenderer->outputTex);
 345	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 346	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 347	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 348	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 349	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, GBA_VIDEO_HORIZONTAL_PIXELS * glRenderer->scale, GBA_VIDEO_VERTICAL_PIXELS * glRenderer->scale, 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
 350	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, glRenderer->outputTex, 0);
 351
 352	glBindTexture(GL_TEXTURE_2D, glRenderer->layers[GBA_GL_TEX_COMPOSITE_FLAGS]);
 353	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 354	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 355	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 356	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 357	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, GBA_VIDEO_HORIZONTAL_PIXELS * glRenderer->scale, GBA_VIDEO_VERTICAL_PIXELS * glRenderer->scale, 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
 358	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, glRenderer->layers[GBA_GL_TEX_COMPOSITE_FLAGS], 0);
 359
 360	glBindFramebuffer(GL_FRAMEBUFFER, 0);
 361
 362	int i;
 363	for (i = 0; i < 4; ++i) {
 364		glRenderer->bg[i].index = i;
 365		glGenFramebuffers(1, &glRenderer->bg[i].fbo);
 366		glGenTextures(1, &glRenderer->bg[i].tex);
 367		glGenTextures(1, &glRenderer->bg[i].flags);
 368		glBindFramebuffer(GL_FRAMEBUFFER, glRenderer->bg[i].fbo);
 369
 370		glBindTexture(GL_TEXTURE_2D, glRenderer->bg[i].tex);
 371		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 372		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 373		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 374		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 375		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, GBA_VIDEO_HORIZONTAL_PIXELS * glRenderer->scale, GBA_VIDEO_VERTICAL_PIXELS * glRenderer->scale, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
 376		glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, glRenderer->bg[i].tex, 0);
 377
 378		glBindTexture(GL_TEXTURE_2D, glRenderer->bg[i].flags);
 379		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 380		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 381		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 382		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 383		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, GBA_VIDEO_HORIZONTAL_PIXELS * glRenderer->scale, GBA_VIDEO_VERTICAL_PIXELS * glRenderer->scale, 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
 384		glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, glRenderer->bg[i].flags, 0);
 385
 386		glBindFramebuffer(GL_FRAMEBUFFER, 0);
 387	}
 388
 389	glRenderer->compositeProgram = glCreateProgram();
 390	glRenderer->objProgram[0] = glCreateProgram();
 391	glRenderer->objProgram[1] = glCreateProgram();
 392	glRenderer->bgProgram[0] = glCreateProgram();
 393	glRenderer->bgProgram[1] = glCreateProgram();
 394	glRenderer->bgProgram[2] = glCreateProgram();
 395	glRenderer->bgProgram[3] = glCreateProgram();
 396	glRenderer->bgProgram[4] = glCreateProgram();
 397	glRenderer->bgProgram[5] = glCreateProgram();
 398
 399	char log[1024];
 400	const GLchar* shaderBuffer[8];
 401	shaderBuffer[0] = _gl3Header;
 402
 403	GLuint vs = glCreateShader(GL_VERTEX_SHADER);
 404	shaderBuffer[1] = _vertexShader;
 405	glShaderSource(vs, 2, shaderBuffer, 0);
 406	glCompileShader(vs);
 407	glGetShaderInfoLog(vs, 1024, 0, log);
 408	if (log[0]) {
 409		mLOG(GBA_VIDEO, ERROR, "Vertex shader compilation failure: %s", log);
 410	}
 411
 412	shaderBuffer[1] = _renderMode0;
 413
 414	shaderBuffer[2] = _renderTile16;
 415	_compileShader(glRenderer, glRenderer->bgProgram[0], shaderBuffer, 3, vs, log);
 416
 417	shaderBuffer[2] = _renderTile256;
 418	_compileShader(glRenderer, glRenderer->bgProgram[1], shaderBuffer, 3, vs, log);
 419
 420	shaderBuffer[1] = _renderMode2;
 421
 422	shaderBuffer[2] = _fetchTileOverflow;
 423	_compileShader(glRenderer, glRenderer->bgProgram[2], shaderBuffer, 3, vs, log);
 424
 425	shaderBuffer[2] = _fetchTileNoOverflow;
 426	_compileShader(glRenderer, glRenderer->bgProgram[3], shaderBuffer, 3, vs, log);
 427
 428	shaderBuffer[1] = _renderObj;
 429
 430	shaderBuffer[2] = _renderTile16;
 431	_compileShader(glRenderer, glRenderer->objProgram[0], shaderBuffer, 3, vs, log);
 432
 433	shaderBuffer[2] = _renderTile256;
 434	_compileShader(glRenderer, glRenderer->objProgram[1], shaderBuffer, 3, vs, log);
 435
 436	shaderBuffer[1] = _composite;
 437	_compileShader(glRenderer, glRenderer->compositeProgram, shaderBuffer, 2, vs, log);
 438
 439	glDeleteShader(vs);
 440
 441	GBAVideoGLRendererReset(renderer);
 442}
 443
 444void GBAVideoGLRendererDeinit(struct GBAVideoRenderer* renderer) {
 445	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
 446	glDeleteFramebuffers(2, glRenderer->fbo);
 447	glDeleteTextures(3, glRenderer->layers);
 448	glDeleteTextures(1, &glRenderer->paletteTex);
 449	glDeleteTextures(1, &glRenderer->vramTex);
 450	glDeleteTextures(1, &glRenderer->oamTex);
 451
 452	glDeleteProgram(glRenderer->bgProgram[0]);
 453	glDeleteProgram(glRenderer->bgProgram[1]);
 454	glDeleteProgram(glRenderer->bgProgram[2]);
 455	glDeleteProgram(glRenderer->bgProgram[3]);
 456	glDeleteProgram(glRenderer->bgProgram[4]);
 457	glDeleteProgram(glRenderer->bgProgram[5]);
 458	glDeleteProgram(glRenderer->bgProgram[6]);
 459	glDeleteProgram(glRenderer->objProgram[0]);
 460	glDeleteProgram(glRenderer->objProgram[1]);
 461	glDeleteProgram(glRenderer->compositeProgram);
 462}
 463
 464void GBAVideoGLRendererReset(struct GBAVideoRenderer* renderer) {
 465	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
 466
 467	glRenderer->paletteDirty = true;
 468	glRenderer->vramDirty = 0xFFFFFF;
 469	glRenderer->firstAffine = -1;
 470}
 471
 472void GBAVideoGLRendererWriteVRAM(struct GBAVideoRenderer* renderer, uint32_t address) {
 473	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
 474	glRenderer->vramDirty |= 1 << (address >> 12);
 475}
 476
 477void GBAVideoGLRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam) {
 478	UNUSED(oam);
 479	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
 480	glRenderer->oamDirty = true;
 481}
 482
 483void GBAVideoGLRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
 484	UNUSED(address);
 485	UNUSED(value);
 486	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
 487	glRenderer->paletteDirty = true;
 488}
 489
 490uint16_t GBAVideoGLRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
 491	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
 492	if (renderer->cache) {
 493		GBAVideoCacheWriteVideoRegister(renderer->cache, address, value);
 494	}
 495
 496	switch (address) {
 497	case REG_DISPCNT:
 498		value &= 0xFFF7;
 499		glRenderer->dispcnt = value;
 500		GBAVideoGLRendererUpdateDISPCNT(glRenderer);
 501		break;
 502	case REG_BG0CNT:
 503		value &= 0xDFFF;
 504		GBAVideoGLRendererWriteBGCNT(&glRenderer->bg[0], value);
 505		break;
 506	case REG_BG1CNT:
 507		value &= 0xDFFF;
 508		GBAVideoGLRendererWriteBGCNT(&glRenderer->bg[1], value);
 509		break;
 510	case REG_BG2CNT:
 511		value &= 0xFFFF;
 512		GBAVideoGLRendererWriteBGCNT(&glRenderer->bg[2], value);
 513		break;
 514	case REG_BG3CNT:
 515		value &= 0xFFFF;
 516		GBAVideoGLRendererWriteBGCNT(&glRenderer->bg[3], value);
 517		break;
 518	case REG_BG0HOFS:
 519		value &= 0x01FF;
 520		glRenderer->bg[0].x = value;
 521		break;
 522	case REG_BG0VOFS:
 523		value &= 0x01FF;
 524		glRenderer->bg[0].y = value;
 525		break;
 526	case REG_BG1HOFS:
 527		value &= 0x01FF;
 528		glRenderer->bg[1].x = value;
 529		break;
 530	case REG_BG1VOFS:
 531		value &= 0x01FF;
 532		glRenderer->bg[1].y = value;
 533		break;
 534	case REG_BG2HOFS:
 535		value &= 0x01FF;
 536		glRenderer->bg[2].x = value;
 537		break;
 538	case REG_BG2VOFS:
 539		value &= 0x01FF;
 540		glRenderer->bg[2].y = value;
 541		break;
 542	case REG_BG3HOFS:
 543		value &= 0x01FF;
 544		glRenderer->bg[3].x = value;
 545		break;
 546	case REG_BG3VOFS:
 547		value &= 0x01FF;
 548		glRenderer->bg[3].y = value;
 549		break;
 550	case REG_BG2PA:
 551		glRenderer->bg[2].affine[0].dx = value;
 552		break;
 553	case REG_BG2PB:
 554		glRenderer->bg[2].affine[0].dmx = value;
 555		break;
 556	case REG_BG2PC:
 557		glRenderer->bg[2].affine[0].dy = value;
 558		break;
 559	case REG_BG2PD:
 560		glRenderer->bg[2].affine[0].dmy = value;
 561		break;
 562	case REG_BG2X_LO:
 563		GBAVideoGLRendererWriteBGX_LO(&glRenderer->bg[2], value);
 564		break;
 565	case REG_BG2X_HI:
 566		GBAVideoGLRendererWriteBGX_HI(&glRenderer->bg[2], value);
 567		break;
 568	case REG_BG2Y_LO:
 569		GBAVideoGLRendererWriteBGY_LO(&glRenderer->bg[2], value);
 570		break;
 571	case REG_BG2Y_HI:
 572		GBAVideoGLRendererWriteBGY_HI(&glRenderer->bg[2], value);
 573		break;
 574	case REG_BG3PA:
 575		glRenderer->bg[3].affine[0].dx = value;
 576		break;
 577	case REG_BG3PB:
 578		glRenderer->bg[3].affine[0].dmx = value;
 579		break;
 580	case REG_BG3PC:
 581		glRenderer->bg[3].affine[0].dy = value;
 582		break;
 583	case REG_BG3PD:
 584		glRenderer->bg[3].affine[0].dmy = value;
 585		break;
 586	case REG_BG3X_LO:
 587		GBAVideoGLRendererWriteBGX_LO(&glRenderer->bg[3], value);
 588		break;
 589	case REG_BG3X_HI:
 590		GBAVideoGLRendererWriteBGX_HI(&glRenderer->bg[3], value);
 591		break;
 592	case REG_BG3Y_LO:
 593		GBAVideoGLRendererWriteBGY_LO(&glRenderer->bg[3], value);
 594		break;
 595	case REG_BG3Y_HI:
 596		GBAVideoGLRendererWriteBGY_HI(&glRenderer->bg[3], value);
 597		break;
 598	case REG_BLDCNT:
 599		GBAVideoGLRendererWriteBLDCNT(glRenderer, value);
 600		value &= 0x3FFF;
 601		break;
 602	case REG_BLDALPHA:
 603		glRenderer->blda = value & 0x1F;
 604		if (glRenderer->blda > 0x10) {
 605			glRenderer->blda = 0x10;
 606		}
 607		glRenderer->bldb = (value >> 8) & 0x1F;
 608		if (glRenderer->bldb > 0x10) {
 609			glRenderer->bldb = 0x10;
 610		}
 611		value &= 0x1F1F;
 612		break;
 613	case REG_BLDY:
 614		value &= 0x1F;
 615		if (value > 0x10) {
 616			value = 0x10;
 617		}
 618		if (glRenderer->bldy != value) {
 619			glRenderer->bldy = value;
 620		}
 621		break;
 622	case REG_WIN0H:
 623		/*glRenderer->winN[0].h.end = value;
 624		glRenderer->winN[0].h.start = value >> 8;
 625		if (glRenderer->winN[0].h.start > GBA_VIDEO_HORIZONTAL_PIXELS && glRenderer->winN[0].h.start > glRenderer->winN[0].h.end) {
 626			glRenderer->winN[0].h.start = 0;
 627		}
 628		if (glRenderer->winN[0].h.end > GBA_VIDEO_HORIZONTAL_PIXELS) {
 629			glRenderer->winN[0].h.end = GBA_VIDEO_HORIZONTAL_PIXELS;
 630			if (glRenderer->winN[0].h.start > GBA_VIDEO_HORIZONTAL_PIXELS) {
 631				glRenderer->winN[0].h.start = GBA_VIDEO_HORIZONTAL_PIXELS;
 632			}
 633		}*/
 634		break;
 635	case REG_WIN1H:
 636		/*glRenderer->winN[1].h.end = value;
 637		glRenderer->winN[1].h.start = value >> 8;
 638		if (glRenderer->winN[1].h.start > GBA_VIDEO_HORIZONTAL_PIXELS && glRenderer->winN[1].h.start > glRenderer->winN[1].h.end) {
 639			glRenderer->winN[1].h.start = 0;
 640		}
 641		if (glRenderer->winN[1].h.end > GBA_VIDEO_HORIZONTAL_PIXELS) {
 642			glRenderer->winN[1].h.end = GBA_VIDEO_HORIZONTAL_PIXELS;
 643			if (glRenderer->winN[1].h.start > GBA_VIDEO_HORIZONTAL_PIXELS) {
 644				glRenderer->winN[1].h.start = GBA_VIDEO_HORIZONTAL_PIXELS;
 645			}
 646		}*/
 647		break;
 648	case REG_WIN0V:
 649		/*glRenderer->winN[0].v.end = value;
 650		glRenderer->winN[0].v.start = value >> 8;
 651		if (glRenderer->winN[0].v.start > GBA_VIDEO_VERTICAL_PIXELS && glRenderer->winN[0].v.start > glRenderer->winN[0].v.end) {
 652			glRenderer->winN[0].v.start = 0;
 653		}
 654		if (glRenderer->winN[0].v.end > GBA_VIDEO_VERTICAL_PIXELS) {
 655			glRenderer->winN[0].v.end = GBA_VIDEO_VERTICAL_PIXELS;
 656			if (glRenderer->winN[0].v.start > GBA_VIDEO_VERTICAL_PIXELS) {
 657				glRenderer->winN[0].v.start = GBA_VIDEO_VERTICAL_PIXELS;
 658			}
 659		}*/
 660		break;
 661	case REG_WIN1V:
 662		/*glRenderer->winN[1].v.end = value;
 663		glRenderer->winN[1].v.start = value >> 8;
 664		if (glRenderer->winN[1].v.start > GBA_VIDEO_VERTICAL_PIXELS && glRenderer->winN[1].v.start > glRenderer->winN[1].v.end) {
 665			glRenderer->winN[1].v.start = 0;
 666		}
 667		if (glRenderer->winN[1].v.end > GBA_VIDEO_VERTICAL_PIXELS) {
 668			glRenderer->winN[1].v.end = GBA_VIDEO_VERTICAL_PIXELS;
 669			if (glRenderer->winN[1].v.start > GBA_VIDEO_VERTICAL_PIXELS) {
 670				glRenderer->winN[1].v.start = GBA_VIDEO_VERTICAL_PIXELS;
 671			}
 672		}*/
 673		break;
 674	case REG_WININ:
 675		value &= 0x3F3F;
 676		//glRenderer->winN[0].control.packed = value;
 677		//glRenderer->winN[1].control.packed = value >> 8;
 678		break;
 679	case REG_WINOUT:
 680		value &= 0x3F3F;
 681		//glRenderer->winout.packed = value;
 682		//glRenderer->objwin.packed = value >> 8;
 683		break;
 684	case REG_MOSAIC:
 685		glRenderer->mosaic = value;
 686		break;
 687	case REG_GREENSWP:
 688		mLOG(GBA_VIDEO, STUB, "Stub video register write: 0x%03X", address);
 689		break;
 690	default:
 691		mLOG(GBA_VIDEO, GAME_ERROR, "Invalid video register: 0x%03X", address);
 692	}
 693	return value;
 694}
 695
 696void GBAVideoGLRendererDrawScanline(struct GBAVideoRenderer* renderer, int y) {
 697	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
 698	if (glRenderer->paletteDirty) {
 699		glBindTexture(GL_TEXTURE_2D, glRenderer->paletteTex);
 700		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB5_A1, 16, 32, 0, GL_RGBA, GL_UNSIGNED_SHORT_1_5_5_5_REV, glRenderer->d.palette);
 701		glRenderer->paletteDirty = false;
 702	}
 703	int i;
 704	for (i = 0; i < 24; ++i) {
 705		if (!(glRenderer->vramDirty & (1 << i))) {
 706			continue;
 707		}
 708		// TODO: PBOs
 709		glBindTexture(GL_TEXTURE_2D, glRenderer->vramTex);
 710		glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 8 * i, 256, 8, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, &glRenderer->d.vram[2048 * i]);
 711	}
 712	glRenderer->vramDirty = 0;
 713
 714	uint32_t backdrop = M_RGB5_TO_RGB8(renderer->palette[0]);
 715	glClearColor(((backdrop >> 16) & 0xFF) / 256., ((backdrop >> 8) & 0xFF) / 256., (backdrop & 0xFF) / 256., 0.f);
 716	glBindFramebuffer(GL_FRAMEBUFFER, glRenderer->fbo[GBA_GL_FBO_COMPOSITE]);
 717	glEnable(GL_SCISSOR_TEST);
 718	glScissor(0, y * glRenderer->scale, GBA_VIDEO_HORIZONTAL_PIXELS * glRenderer->scale, glRenderer->scale);
 719	glDrawBuffer(GL_COLOR_ATTACHMENT0);
 720	glClear(GL_COLOR_BUFFER_BIT);
 721	if (y == 0) {
 722		glDisable(GL_SCISSOR_TEST);
 723		glDrawBuffer(GL_COLOR_ATTACHMENT1);
 724		glClearColor(1, (glRenderer->target1Bd | (glRenderer->target2Bd * 2)) / 8.f, 0, 1);
 725		glClear(GL_COLOR_BUFFER_BIT);
 726		
 727		glClearColor(0, 0, 0, 0);
 728		glBindFramebuffer(GL_FRAMEBUFFER, glRenderer->fbo[GBA_GL_FBO_OBJ]);
 729		glDrawBuffer(GL_COLOR_ATTACHMENT0);
 730		glClear(GL_COLOR_BUFFER_BIT);
 731		glDrawBuffer(GL_COLOR_ATTACHMENT1);
 732		glClear(GL_COLOR_BUFFER_BIT);
 733
 734		for (i = 0; i < 4; ++i) {
 735			glBindFramebuffer(GL_FRAMEBUFFER, glRenderer->bg[i].fbo);
 736			glDrawBuffer(GL_COLOR_ATTACHMENT0);
 737			glClear(GL_COLOR_BUFFER_BIT);
 738			glDrawBuffer(GL_COLOR_ATTACHMENT1);
 739			glClear(GL_COLOR_BUFFER_BIT);
 740		}
 741		glDrawBuffer(GL_COLOR_ATTACHMENT0);
 742		glEnable(GL_SCISSOR_TEST);
 743	}
 744	glBindFramebuffer(GL_FRAMEBUFFER, 0);
 745
 746	if (GBARegisterDISPCNTGetMode(glRenderer->dispcnt) != 0) {
 747		if (glRenderer->firstAffine < 0) {
 748			memcpy(&glRenderer->bg[2].affine[3], &glRenderer->bg[2].affine[0], sizeof(struct GBAVideoGLAffine));
 749			memcpy(&glRenderer->bg[3].affine[3], &glRenderer->bg[3].affine[0], sizeof(struct GBAVideoGLAffine));
 750			memcpy(&glRenderer->bg[2].affine[2], &glRenderer->bg[2].affine[0], sizeof(struct GBAVideoGLAffine));
 751			memcpy(&glRenderer->bg[3].affine[2], &glRenderer->bg[3].affine[0], sizeof(struct GBAVideoGLAffine));
 752			memcpy(&glRenderer->bg[2].affine[1], &glRenderer->bg[2].affine[0], sizeof(struct GBAVideoGLAffine));
 753			memcpy(&glRenderer->bg[3].affine[1], &glRenderer->bg[3].affine[0], sizeof(struct GBAVideoGLAffine));
 754			glRenderer->firstAffine = y;
 755		} else if (y - glRenderer->firstAffine == 1) {
 756			memcpy(&glRenderer->bg[2].affine[1], &glRenderer->bg[2].affine[0], sizeof(struct GBAVideoGLAffine));
 757			memcpy(&glRenderer->bg[3].affine[1], &glRenderer->bg[3].affine[0], sizeof(struct GBAVideoGLAffine));			
 758		}
 759	} else {
 760		glRenderer->firstAffine = -1;
 761	}
 762
 763	int spriteLayers = 0;
 764	if (GBARegisterDISPCNTIsObjEnable(glRenderer->dispcnt) && !glRenderer->d.disableOBJ) {
 765		if (glRenderer->oamDirty) {
 766			glBindTexture(GL_TEXTURE_2D, glRenderer->oamTex);
 767			glTexImage2D(GL_TEXTURE_2D, 0, GL_R16UI, 4, 128, 0, GL_RED_INTEGER, GL_UNSIGNED_SHORT, glRenderer->d.oam);
 768			glRenderer->oamMax = GBAVideoRendererCleanOAM(glRenderer->d.oam->obj, glRenderer->sprites, 0);
 769			glRenderer->oamDirty = false;
 770		}
 771		int i;
 772		for (i = glRenderer->oamMax; i--;) {
 773			struct GBAVideoRendererSprite* sprite = &glRenderer->sprites[i];
 774			if ((y < sprite->y && (sprite->endY - 256 < 0 || y >= sprite->endY - 256)) || y >= sprite->endY) {
 775				continue;
 776			}
 777
 778			GBAVideoGLRendererDrawSprite(glRenderer, &sprite->obj, y, sprite->y);
 779			spriteLayers |= 1 << GBAObjAttributesCGetPriority(sprite->obj.c);
 780		}
 781	}
 782
 783	_compositeLayer(glRenderer, glRenderer->layers[GBA_GL_TEX_OBJ_COLOR], glRenderer->layers[GBA_GL_TEX_OBJ_FLAGS], y);
 784	unsigned priority;
 785	for (priority = 4; priority--;) {
 786		if (TEST_LAYER_ENABLED(0) && GBARegisterDISPCNTGetMode(glRenderer->dispcnt) < 2) {
 787			GBAVideoGLRendererDrawBackgroundMode0(glRenderer, &glRenderer->bg[0], y);
 788		}
 789		if (TEST_LAYER_ENABLED(1) && GBARegisterDISPCNTGetMode(glRenderer->dispcnt) < 2) {
 790			GBAVideoGLRendererDrawBackgroundMode0(glRenderer, &glRenderer->bg[1], y);
 791		}
 792		if (TEST_LAYER_ENABLED(2)) {
 793			switch (GBARegisterDISPCNTGetMode(glRenderer->dispcnt)) {
 794			case 0:
 795				GBAVideoGLRendererDrawBackgroundMode0(glRenderer, &glRenderer->bg[2], y);
 796				break;
 797			case 1:
 798			case 2:
 799				GBAVideoGLRendererDrawBackgroundMode2(glRenderer, &glRenderer->bg[2], y);
 800				break;
 801			case 3:
 802				//GBAVideoGLRendererDrawBackgroundMode3(glRenderer, &glRenderer->bg[2], y);
 803				break;
 804			case 4:
 805				//GBAVideoGLRendererDrawBackgroundMode4(glRenderer, &glRenderer->bg[2], y);
 806				break;
 807			case 5:
 808				//GBAVideoGLRendererDrawBackgroundMode5(glRenderer, &glRenderer->bg[2], y);
 809				break;
 810			}
 811		}
 812		if (TEST_LAYER_ENABLED(3)) {
 813			switch (GBARegisterDISPCNTGetMode(glRenderer->dispcnt)) {
 814			case 0:
 815				GBAVideoGLRendererDrawBackgroundMode0(glRenderer, &glRenderer->bg[3], y);
 816				break;
 817			case 2:
 818				GBAVideoGLRendererDrawBackgroundMode2(glRenderer, &glRenderer->bg[3], y);
 819				break;
 820			}
 821		}
 822	}
 823
 824	if (GBARegisterDISPCNTGetMode(glRenderer->dispcnt) != 0) {
 825		memcpy(&glRenderer->bg[2].affine[3], &glRenderer->bg[2].affine[2], sizeof(struct GBAVideoGLAffine));
 826		memcpy(&glRenderer->bg[3].affine[3], &glRenderer->bg[3].affine[2], sizeof(struct GBAVideoGLAffine));
 827		memcpy(&glRenderer->bg[2].affine[2], &glRenderer->bg[2].affine[1], sizeof(struct GBAVideoGLAffine));
 828		memcpy(&glRenderer->bg[3].affine[2], &glRenderer->bg[3].affine[1], sizeof(struct GBAVideoGLAffine));
 829		memcpy(&glRenderer->bg[2].affine[1], &glRenderer->bg[2].affine[0], sizeof(struct GBAVideoGLAffine));
 830		memcpy(&glRenderer->bg[3].affine[1], &glRenderer->bg[3].affine[0], sizeof(struct GBAVideoGLAffine));
 831
 832		glRenderer->bg[2].affine[0].sx += glRenderer->bg[2].affine[0].dmx;
 833		glRenderer->bg[2].affine[0].sy += glRenderer->bg[2].affine[0].dmy;
 834		glRenderer->bg[3].affine[0].sx += glRenderer->bg[3].affine[0].dmx;
 835		glRenderer->bg[3].affine[0].sy += glRenderer->bg[3].affine[0].dmy;
 836	}
 837}
 838
 839void GBAVideoGLRendererFinishFrame(struct GBAVideoRenderer* renderer) {
 840	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
 841	glRenderer->firstAffine = -1;
 842	glRenderer->bg[2].affine[0].sx = glRenderer->bg[2].refx;
 843	glRenderer->bg[2].affine[0].sy = glRenderer->bg[2].refy;
 844	glRenderer->bg[3].affine[0].sx = glRenderer->bg[3].refx;
 845	glRenderer->bg[3].affine[0].sy = glRenderer->bg[3].refy;
 846	glFlush();
 847}
 848
 849void GBAVideoGLRendererGetPixels(struct GBAVideoRenderer* renderer, size_t* stride, const void** pixels) {
 850
 851}
 852
 853void GBAVideoGLRendererPutPixels(struct GBAVideoRenderer* renderer, size_t stride, const void* pixels) {
 854
 855}
 856
 857static void _enableBg(struct GBAVideoGLRenderer* renderer, int bg, bool active) {
 858	int wasActive = renderer->bg[bg].enabled;
 859	if (!active) {
 860		renderer->bg[bg].enabled = 0;
 861	} else if (!wasActive && active) {
 862		/*if (renderer->nextY == 0 || GBARegisterDISPCNTGetMode(renderer->dispcnt) > 2) {
 863			// TODO: Investigate in more depth how switching background works in different modes
 864			renderer->bg[bg].enabled = 4;
 865		} else {
 866			renderer->bg[bg].enabled = 1;
 867		}*/
 868		renderer->bg[bg].enabled = 4;
 869	}
 870}
 871
 872static void GBAVideoGLRendererUpdateDISPCNT(struct GBAVideoGLRenderer* renderer) {
 873	_enableBg(renderer, 0, GBARegisterDISPCNTGetBg0Enable(renderer->dispcnt));
 874	_enableBg(renderer, 1, GBARegisterDISPCNTGetBg1Enable(renderer->dispcnt));
 875	_enableBg(renderer, 2, GBARegisterDISPCNTGetBg2Enable(renderer->dispcnt));
 876	_enableBg(renderer, 3, GBARegisterDISPCNTGetBg3Enable(renderer->dispcnt));
 877}
 878
 879static void GBAVideoGLRendererWriteBGCNT(struct GBAVideoGLBackground* bg, uint16_t value) {
 880	bg->priority = GBARegisterBGCNTGetPriority(value);
 881	bg->charBase = GBARegisterBGCNTGetCharBase(value) << 13;
 882	bg->mosaic = GBARegisterBGCNTGetMosaic(value);
 883	bg->multipalette = GBARegisterBGCNTGet256Color(value);
 884	bg->screenBase = GBARegisterBGCNTGetScreenBase(value) << 10;
 885	bg->overflow = GBARegisterBGCNTGetOverflow(value);
 886	bg->size = GBARegisterBGCNTGetSize(value);
 887}
 888
 889static void GBAVideoGLRendererWriteBGX_LO(struct GBAVideoGLBackground* bg, uint16_t value) {
 890	bg->refx = (bg->refx & 0xFFFF0000) | value;
 891	bg->affine[0].sx = bg->refx;
 892}
 893
 894static void GBAVideoGLRendererWriteBGX_HI(struct GBAVideoGLBackground* bg, uint16_t value) {
 895	bg->refx = (bg->refx & 0x0000FFFF) | (value << 16);
 896	bg->refx <<= 4;
 897	bg->refx >>= 4;
 898	bg->affine[0].sx = bg->refx;
 899}
 900
 901static void GBAVideoGLRendererWriteBGY_LO(struct GBAVideoGLBackground* bg, uint16_t value) {
 902	bg->refy = (bg->refy & 0xFFFF0000) | value;
 903	bg->affine[0].sy = bg->refy;
 904}
 905
 906static void GBAVideoGLRendererWriteBGY_HI(struct GBAVideoGLBackground* bg, uint16_t value) {
 907	bg->refy = (bg->refy & 0x0000FFFF) | (value << 16);
 908	bg->refy <<= 4;
 909	bg->refy >>= 4;
 910	bg->affine[0].sy = bg->refy;
 911}
 912
 913static void GBAVideoGLRendererWriteBLDCNT(struct GBAVideoGLRenderer* renderer, uint16_t value) {
 914	renderer->bg[0].target1 = GBARegisterBLDCNTGetTarget1Bg0(value);
 915	renderer->bg[1].target1 = GBARegisterBLDCNTGetTarget1Bg1(value);
 916	renderer->bg[2].target1 = GBARegisterBLDCNTGetTarget1Bg2(value);
 917	renderer->bg[3].target1 = GBARegisterBLDCNTGetTarget1Bg3(value);
 918	renderer->bg[0].target2 = GBARegisterBLDCNTGetTarget2Bg0(value);
 919	renderer->bg[1].target2 = GBARegisterBLDCNTGetTarget2Bg1(value);
 920	renderer->bg[2].target2 = GBARegisterBLDCNTGetTarget2Bg2(value);
 921	renderer->bg[3].target2 = GBARegisterBLDCNTGetTarget2Bg3(value);
 922
 923	renderer->blendEffect = GBARegisterBLDCNTGetEffect(value);
 924	renderer->target1Obj = GBARegisterBLDCNTGetTarget1Obj(value);
 925	renderer->target1Bd = GBARegisterBLDCNTGetTarget1Bd(value);
 926	renderer->target2Obj = GBARegisterBLDCNTGetTarget2Obj(value);
 927	renderer->target2Bd = GBARegisterBLDCNTGetTarget2Bd(value);
 928}
 929
 930static void _compositeLayer(struct GBAVideoGLRenderer* renderer, GLuint tex, GLuint flags, int y) {
 931	if ((y & 0x1F) != 0x1F) {
 932		return;
 933	}
 934	glBindFramebuffer(GL_FRAMEBUFFER, renderer->fbo[GBA_GL_FBO_COMPOSITE]);
 935	glViewport(0, 0, GBA_VIDEO_HORIZONTAL_PIXELS * renderer->scale, GBA_VIDEO_VERTICAL_PIXELS * renderer->scale);
 936	glScissor(0, (y & ~0x1F) * renderer->scale, GBA_VIDEO_HORIZONTAL_PIXELS * renderer->scale, 0x20 * renderer->scale);
 937	glUseProgram(renderer->compositeProgram);
 938	glActiveTexture(GL_TEXTURE0);
 939	glBindTexture(GL_TEXTURE_2D, tex);
 940	glActiveTexture(GL_TEXTURE0 + 1);
 941	glBindTexture(GL_TEXTURE_2D, flags);
 942	glActiveTexture(GL_TEXTURE0 + 2);
 943	glBindTexture(GL_TEXTURE_2D, renderer->outputTex);
 944	glActiveTexture(GL_TEXTURE0 + 3);
 945	glBindTexture(GL_TEXTURE_2D, renderer->layers[GBA_GL_TEX_COMPOSITE_FLAGS]);
 946	glUniform2i(0, 0x20, y & ~0x1F);
 947	glUniform2i(1, GBA_VIDEO_HORIZONTAL_PIXELS, GBA_VIDEO_VERTICAL_PIXELS);
 948	glUniform1i(2, renderer->scale);
 949	glUniform3f(3, renderer->blda / 16.f, renderer->bldb / 16.f, renderer->bldy / 16.f);
 950	glUniform1i(4, 0);
 951	glUniform1i(5, 1);
 952	glUniform1i(6, 2);
 953	glUniform1i(7, 3);
 954	glVertexAttribPointer(0, 2, GL_INT, GL_FALSE, 0, _vertices);
 955	glEnableVertexAttribArray(0);
 956	glDrawBuffers(2, (GLenum[]) { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1 });
 957	glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
 958	glDrawBuffers(1, (GLenum[]) { GL_COLOR_ATTACHMENT0 });
 959	glBindFramebuffer(GL_FRAMEBUFFER, 0);
 960}
 961
 962void GBAVideoGLRendererDrawSprite(struct GBAVideoGLRenderer* renderer, struct GBAObj* sprite, int y, int spriteY) {
 963	int width = GBAVideoObjSizes[GBAObjAttributesAGetShape(sprite->a) * 4 + GBAObjAttributesBGetSize(sprite->b)][0];
 964	int height = GBAVideoObjSizes[GBAObjAttributesAGetShape(sprite->a) * 4 + GBAObjAttributesBGetSize(sprite->b)][1];
 965	int32_t x = (uint32_t) GBAObjAttributesBGetX(sprite->b) << 23;
 966	x >>= 23;
 967
 968	int align = GBAObjAttributesAIs256Color(sprite->a) && !GBARegisterDISPCNTIsObjCharacterMapping(renderer->dispcnt);
 969	unsigned charBase = (BASE_TILE >> 1) + (GBAObjAttributesCGetTile(sprite->c) & ~align) * 0x10;
 970	int stride = GBARegisterDISPCNTIsObjCharacterMapping(renderer->dispcnt) ? (width >> 3) : (0x40 >> !GBAObjAttributesAIs256Color(sprite->a));
 971
 972	if (spriteY + height >= 256) {
 973		spriteY -= 256;
 974	}
 975
 976	if (!GBAObjAttributesAIsTransformed(sprite->a) && GBAObjAttributesBIsVFlip(sprite->b)) {
 977		spriteY = (y - height) + (y - spriteY) + 1;
 978	}
 979
 980	int totalWidth = width;
 981	int totalHeight = height;
 982	if (GBAObjAttributesAIsTransformed(sprite->a) && GBAObjAttributesAIsDoubleSize(sprite->a)) {
 983		totalWidth <<= 1;
 984		totalHeight <<= 1;
 985	}
 986
 987	glBindFramebuffer(GL_FRAMEBUFFER, renderer->fbo[GBA_GL_FBO_OBJ]);
 988	glViewport(x * renderer->scale, spriteY * renderer->scale, totalWidth * renderer->scale, totalHeight * renderer->scale);
 989	glScissor(x * renderer->scale, y * renderer->scale, totalWidth * renderer->scale, renderer->scale);
 990	glUseProgram(renderer->objProgram[GBAObjAttributesAGet256Color(sprite->a)]);
 991	glActiveTexture(GL_TEXTURE0);
 992	glBindTexture(GL_TEXTURE_2D, renderer->vramTex);
 993	glActiveTexture(GL_TEXTURE0 + 1);
 994	glBindTexture(GL_TEXTURE_2D, renderer->paletteTex);
 995	glUniform2i(0, 1, y - spriteY);
 996	glUniform2i(1, (GBAObjAttributesBIsHFlip(sprite->b) && !GBAObjAttributesAIsTransformed(sprite->a)) ? -totalWidth : totalWidth, totalHeight);
 997	glUniform1i(2, 0);
 998	glUniform1i(3, 1);
 999	glUniform1i(4, charBase);
1000	glUniform1i(5, stride);
1001	glUniform1i(6, GBAObjAttributesCGetPalette(sprite->c));
1002	glUniform3i(7, GBAObjAttributesCGetPriority(sprite->c) << 3, (renderer->target1Obj || GBAObjAttributesAGetMode(sprite->a) == OBJ_MODE_SEMITRANSPARENT) | (renderer->target2Obj * 2), GBAObjAttributesAGetMode(sprite->a) == OBJ_MODE_SEMITRANSPARENT ? BLEND_ALPHA : renderer->blendEffect);
1003	if (GBAObjAttributesAIsTransformed(sprite->a)) {
1004		struct GBAOAMMatrix mat;
1005		LOAD_16(mat.a, 0, &renderer->d.oam->mat[GBAObjAttributesBGetMatIndex(sprite->b)].a);
1006		LOAD_16(mat.b, 0, &renderer->d.oam->mat[GBAObjAttributesBGetMatIndex(sprite->b)].b);
1007		LOAD_16(mat.c, 0, &renderer->d.oam->mat[GBAObjAttributesBGetMatIndex(sprite->b)].c);
1008		LOAD_16(mat.d, 0, &renderer->d.oam->mat[GBAObjAttributesBGetMatIndex(sprite->b)].d);
1009
1010		glUniformMatrix2fv(8, 1, GL_FALSE, (GLfloat[]) { mat.a / 256.f, mat.c / 256.f, mat.b / 256.f, mat.d / 256.f });
1011	} else {
1012		glUniformMatrix2fv(8, 1, GL_FALSE, (GLfloat[]) { 1.f, 0, 0, 1.f });		
1013	}
1014	glUniform4i(9, width, height, totalWidth, totalHeight);
1015	glVertexAttribPointer(0, 2, GL_INT, GL_FALSE, 0, _vertices);
1016	glEnableVertexAttribArray(0);
1017	glDrawBuffers(2, (GLenum[]) { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1 });
1018	glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
1019	glDrawBuffers(1, (GLenum[]) { GL_COLOR_ATTACHMENT0 });
1020}
1021
1022void GBAVideoGLRendererDrawBackgroundMode0(struct GBAVideoGLRenderer* renderer, struct GBAVideoGLBackground* background, int y) {
1023	int inY = y + background->y;
1024	int yBase = inY & 0xFF;
1025	if (background->size == 2) {
1026		yBase += inY & 0x100;
1027	} else if (background->size == 3) {
1028		yBase += (inY & 0x100) << 1;
1029	}
1030	glBindFramebuffer(GL_FRAMEBUFFER, background->fbo);
1031	glViewport(0, 0, GBA_VIDEO_HORIZONTAL_PIXELS * renderer->scale, GBA_VIDEO_VERTICAL_PIXELS * renderer->scale);
1032	glScissor(0, y * renderer->scale, GBA_VIDEO_HORIZONTAL_PIXELS * renderer->scale, renderer->scale);
1033	glUseProgram(renderer->bgProgram[background->multipalette ? 1 : 0]);
1034	glActiveTexture(GL_TEXTURE0);
1035	glBindTexture(GL_TEXTURE_2D, renderer->vramTex);
1036	glActiveTexture(GL_TEXTURE0 + 1);
1037	glBindTexture(GL_TEXTURE_2D, renderer->paletteTex);
1038	glUniform2i(0, 1, y);
1039	glUniform2i(1, GBA_VIDEO_HORIZONTAL_PIXELS, GBA_VIDEO_VERTICAL_PIXELS);
1040	glUniform1i(2, 0);
1041	glUniform1i(3, 1);
1042	glUniform1i(4, background->screenBase);
1043	glUniform1i(5, background->charBase);
1044	glUniform1i(6, background->size);
1045	glUniform2i(7, background->x, yBase - y);
1046	glUniform3i(8, (background->priority << 3) + (background->index << 1) + 1, background->target1 | (background->target2 * 2), renderer->blendEffect);
1047	glVertexAttribPointer(0, 2, GL_INT, GL_FALSE, 0, _vertices);
1048	glEnableVertexAttribArray(0);
1049	glDrawBuffers(2, (GLenum[]) { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1 });
1050	glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
1051	glDrawBuffers(1, (GLenum[]) { GL_COLOR_ATTACHMENT0 });
1052
1053	_compositeLayer(renderer, background->tex, background->flags, y);
1054}
1055
1056void GBAVideoGLRendererDrawBackgroundMode2(struct GBAVideoGLRenderer* renderer, struct GBAVideoGLBackground* background, int y) {
1057	glBindFramebuffer(GL_FRAMEBUFFER, background->fbo);
1058	glViewport(0, 0, GBA_VIDEO_HORIZONTAL_PIXELS * renderer->scale, GBA_VIDEO_VERTICAL_PIXELS * renderer->scale);
1059	glScissor(0, y * renderer->scale, GBA_VIDEO_HORIZONTAL_PIXELS * renderer->scale, renderer->scale);
1060	glUseProgram(renderer->bgProgram[background->overflow ? 2 : 3]);
1061	glActiveTexture(GL_TEXTURE0);
1062	glBindTexture(GL_TEXTURE_2D, renderer->vramTex);
1063	glActiveTexture(GL_TEXTURE0 + 1);
1064	glBindTexture(GL_TEXTURE_2D, renderer->paletteTex);
1065	glUniform2i(0, 1, y);
1066	glUniform2i(1, GBA_VIDEO_HORIZONTAL_PIXELS, GBA_VIDEO_VERTICAL_PIXELS);
1067	glUniform1i(2, 0);
1068	glUniform1i(3, 1);
1069	glUniform1i(4, background->screenBase);
1070	glUniform1i(5, background->charBase);
1071	glUniform1i(6, background->size);
1072	glUniform3i(7, (background->priority << 3) + (background->index << 1) + 1, background->target1 | (background->target2 * 2), renderer->blendEffect);
1073	if (renderer->scale > 1) {
1074		glUniform2iv(8, 4, (GLint[]) {
1075			background->affine[0].sx, background->affine[0].sy,
1076			background->affine[1].sx, background->affine[1].sy,
1077			background->affine[2].sx, background->affine[2].sy,
1078			background->affine[3].sx, background->affine[3].sy,
1079		});
1080		glUniform2iv(12, 4, (GLint[]) {
1081			background->affine[0].dx, background->affine[0].dy,
1082			background->affine[1].dx, background->affine[1].dy,
1083			background->affine[2].dx, background->affine[2].dy,
1084			background->affine[3].dx, background->affine[3].dy,
1085		});
1086	} else {
1087		glUniform2iv(8, 4, (GLint[]) {
1088			background->affine[0].sx, background->affine[0].sy,
1089			background->affine[0].sx, background->affine[0].sy,
1090			background->affine[0].sx, background->affine[0].sy,
1091			background->affine[0].sx, background->affine[0].sy,
1092		});
1093		glUniform2iv(12, 4, (GLint[]) {
1094			background->affine[0].dx, background->affine[0].dy,
1095			background->affine[0].dx, background->affine[0].dy,
1096			background->affine[0].dx, background->affine[0].dy,
1097			background->affine[0].dx, background->affine[0].dy,
1098		});
1099	}
1100	glVertexAttribPointer(0, 2, GL_INT, GL_FALSE, 0, _vertices);
1101	glEnableVertexAttribArray(0);
1102	glDrawBuffers(2, (GLenum[]) { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1 });
1103	glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
1104	glDrawBuffers(1, (GLenum[]) { GL_COLOR_ATTACHMENT0 });
1105
1106	_compositeLayer(renderer, background->tex, background->flags, y);
1107}