--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/video/glrenderer/SDL_renderer_gl.c	Fri Jul 11 00:22:16 2008 +0000
@@ -0,0 +1,960 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997-2006 Sam Lantinga
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+    Sam Lantinga
+    slouken@libsdl.org
+*/
+#include "SDL_config.h"
+
+#if SDL_VIDEO_RENDER_OGL
+
+#include "SDL_video.h"
+#include "SDL_opengl.h"
+#include "SDL_sysvideo.h"
+#include "SDL_pixels_c.h"
+#include "SDL_rect_c.h"
+#include "SDL_yuv_sw_c.h"
+
+#ifdef __MACOSX__
+#include <OpenGL/OpenGL.h>
+#endif
+
+/* OpenGL renderer implementation */
+
+/* Details on optimizing the texture path on Mac OS X:
+   http://developer.apple.com/documentation/GraphicsImaging/Conceptual/OpenGL-MacProgGuide/opengl_texturedata/chapter_10_section_2.html
+*/
+
+static const float inv255f = 1.0f / 255.0f;
+
+static SDL_Renderer *GL_CreateRenderer(SDL_Window * window, Uint32 flags);
+static int GL_ActivateRenderer(SDL_Renderer * renderer);
+static int GL_DisplayModeChanged(SDL_Renderer * renderer);
+static int GL_CreateTexture(SDL_Renderer * renderer, SDL_Texture * texture);
+static int GL_QueryTexturePixels(SDL_Renderer * renderer,
+                                 SDL_Texture * texture, void **pixels,
+                                 int *pitch);
+static int GL_SetTexturePalette(SDL_Renderer * renderer,
+                                SDL_Texture * texture,
+                                const SDL_Color * colors, int firstcolor,
+                                int ncolors);
+static int GL_GetTexturePalette(SDL_Renderer * renderer,
+                                SDL_Texture * texture, SDL_Color * colors,
+                                int firstcolor, int ncolors);
+static int GL_SetTextureColorMod(SDL_Renderer * renderer,
+                                 SDL_Texture * texture);
+static int GL_SetTextureAlphaMod(SDL_Renderer * renderer,
+                                 SDL_Texture * texture);
+static int GL_SetTextureBlendMode(SDL_Renderer * renderer,
+                                  SDL_Texture * texture);
+static int GL_SetTextureScaleMode(SDL_Renderer * renderer,
+                                  SDL_Texture * texture);
+static int GL_UpdateTexture(SDL_Renderer * renderer, SDL_Texture * texture,
+                            const SDL_Rect * rect, const void *pixels,
+                            int pitch);
+static int GL_LockTexture(SDL_Renderer * renderer, SDL_Texture * texture,
+                          const SDL_Rect * rect, int markDirty, void **pixels,
+                          int *pitch);
+static void GL_UnlockTexture(SDL_Renderer * renderer, SDL_Texture * texture);
+static void GL_DirtyTexture(SDL_Renderer * renderer, SDL_Texture * texture,
+                            int numrects, const SDL_Rect * rects);
+static int GL_RenderFill(SDL_Renderer * renderer, Uint8 r, Uint8 g, Uint8 b,
+                         Uint8 a, const SDL_Rect * rect);
+static int GL_RenderCopy(SDL_Renderer * renderer, SDL_Texture * texture,
+                         const SDL_Rect * srcrect, const SDL_Rect * dstrect);
+static void GL_RenderPresent(SDL_Renderer * renderer);
+static void GL_DestroyTexture(SDL_Renderer * renderer, SDL_Texture * texture);
+static void GL_DestroyRenderer(SDL_Renderer * renderer);
+
+
+SDL_RenderDriver GL_RenderDriver = {
+    GL_CreateRenderer,
+    {
+     "opengl",
+     (SDL_RENDERER_SINGLEBUFFER | SDL_RENDERER_PRESENTDISCARD |
+      SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_ACCELERATED),
+     (SDL_TEXTUREMODULATE_NONE | SDL_TEXTUREMODULATE_COLOR |
+      SDL_TEXTUREMODULATE_ALPHA),
+     (SDL_TEXTUREBLENDMODE_NONE | SDL_TEXTUREBLENDMODE_MASK |
+      SDL_TEXTUREBLENDMODE_BLEND | SDL_TEXTUREBLENDMODE_ADD |
+      SDL_TEXTUREBLENDMODE_MOD),
+     (SDL_TEXTURESCALEMODE_NONE | SDL_TEXTURESCALEMODE_FAST |
+      SDL_TEXTURESCALEMODE_SLOW),
+     16,
+     {
+      SDL_PIXELFORMAT_INDEX1LSB,
+      SDL_PIXELFORMAT_INDEX1MSB,
+      SDL_PIXELFORMAT_INDEX8,
+      SDL_PIXELFORMAT_RGB332,
+      SDL_PIXELFORMAT_RGB444,
+      SDL_PIXELFORMAT_RGB555,
+      SDL_PIXELFORMAT_ARGB4444,
+      SDL_PIXELFORMAT_ARGB1555,
+      SDL_PIXELFORMAT_RGB565,
+      SDL_PIXELFORMAT_RGB24,
+      SDL_PIXELFORMAT_BGR24,
+      SDL_PIXELFORMAT_RGB888,
+      SDL_PIXELFORMAT_BGR888,
+      SDL_PIXELFORMAT_ARGB8888,
+      SDL_PIXELFORMAT_ABGR8888,
+      SDL_PIXELFORMAT_ARGB2101010},
+     0,
+     0}
+};
+
+typedef struct
+{
+    SDL_GLContext context;
+    SDL_bool updateSize;
+    SDL_bool GL_ARB_texture_rectangle_supported;
+    SDL_bool GL_EXT_paletted_texture_supported;
+    int blendMode;
+    int scaleMode;
+
+    /* OpenGL functions */
+#define SDL_PROC(ret,func,params) ret (APIENTRY *func) params;
+#include "SDL_glfuncs.h"
+#undef SDL_PROC
+
+    PFNGLCOLORTABLEEXTPROC glColorTableEXT;
+    void (*glTextureRangeAPPLE) (GLenum target, GLsizei length,
+                                 const GLvoid * pointer);
+} GL_RenderData;
+
+typedef struct
+{
+    GLuint texture;
+    GLenum type;
+    GLfloat texw;
+    GLfloat texh;
+    GLenum format;
+    GLenum formattype;
+    Uint8 *palette;
+    void *pixels;
+    int pitch;
+    SDL_DirtyRectList dirty;
+} GL_TextureData;
+
+
+static void
+GL_SetError(const char *prefix, GLenum result)
+{
+    const char *error;
+
+    switch (result) {
+    case GL_NO_ERROR:
+        error = "GL_NO_ERROR";
+        break;
+    case GL_INVALID_ENUM:
+        error = "GL_INVALID_ENUM";
+        break;
+    case GL_INVALID_VALUE:
+        error = "GL_INVALID_VALUE";
+        break;
+    case GL_INVALID_OPERATION:
+        error = "GL_INVALID_OPERATION";
+        break;
+    case GL_STACK_OVERFLOW:
+        error = "GL_STACK_OVERFLOW";
+        break;
+    case GL_STACK_UNDERFLOW:
+        error = "GL_STACK_UNDERFLOW";
+        break;
+    case GL_OUT_OF_MEMORY:
+        error = "GL_OUT_OF_MEMORY";
+        break;
+    case GL_TABLE_TOO_LARGE:
+        error = "GL_TABLE_TOO_LARGE";
+        break;
+    default:
+        error = "UNKNOWN";
+        break;
+    }
+    SDL_SetError("%s: %s", prefix, error);
+}
+
+static int
+GL_LoadFunctions(GL_RenderData * data)
+{
+#if defined(__QNXNTO__) && (_NTO_VERSION < 630)
+#define __SDL_NOGETPROCADDR__
+#elif defined(__MINT__)
+#define __SDL_NOGETPROCADDR__
+#endif
+#ifdef __SDL_NOGETPROCADDR__
+#define SDL_PROC(ret,func,params) data->func=func;
+#else
+#define SDL_PROC(ret,func,params) \
+    do { \
+        data->func = SDL_GL_GetProcAddress(#func); \
+        if ( ! data->func ) { \
+            SDL_SetError("Couldn't load GL function %s: %s\n", #func, SDL_GetError()); \
+            return -1; \
+        } \
+    } while ( 0 );
+#endif /* __SDL_NOGETPROCADDR__ */
+
+#include "SDL_glfuncs.h"
+#undef SDL_PROC
+    return 0;
+}
+
+void
+GL_AddRenderDriver(_THIS)
+{
+    if (_this->GL_CreateContext) {
+        SDL_AddRenderDriver(0, &GL_RenderDriver);
+    }
+}
+
+SDL_Renderer *
+GL_CreateRenderer(SDL_Window * window, Uint32 flags)
+{
+    SDL_Renderer *renderer;
+    GL_RenderData *data;
+    GLint value;
+    int doublebuffer;
+
+    /* Render directly to the window, unless we're compositing */
+#ifndef __MACOSX__
+    if (flags & SDL_RENDERER_SINGLEBUFFER) {
+        SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 0);
+    }
+#endif
+    if (!(window->flags & SDL_WINDOW_OPENGL)) {
+        if (SDL_RecreateWindow(window, window->flags | SDL_WINDOW_OPENGL) < 0) {
+            return NULL;
+        }
+    }
+
+    renderer = (SDL_Renderer *) SDL_calloc(1, sizeof(*renderer));
+    if (!renderer) {
+        SDL_OutOfMemory();
+        return NULL;
+    }
+
+    data = (GL_RenderData *) SDL_calloc(1, sizeof(*data));
+    if (!data) {
+        GL_DestroyRenderer(renderer);
+        SDL_OutOfMemory();
+        return NULL;
+    }
+
+    renderer->ActivateRenderer = GL_ActivateRenderer;
+    renderer->DisplayModeChanged = GL_DisplayModeChanged;
+    renderer->CreateTexture = GL_CreateTexture;
+    renderer->QueryTexturePixels = GL_QueryTexturePixels;
+    renderer->SetTexturePalette = GL_SetTexturePalette;
+    renderer->GetTexturePalette = GL_GetTexturePalette;
+    renderer->SetTextureColorMod = GL_SetTextureColorMod;
+    renderer->SetTextureAlphaMod = GL_SetTextureAlphaMod;
+    renderer->SetTextureBlendMode = GL_SetTextureBlendMode;
+    renderer->SetTextureScaleMode = GL_SetTextureScaleMode;
+    renderer->UpdateTexture = GL_UpdateTexture;
+    renderer->LockTexture = GL_LockTexture;
+    renderer->UnlockTexture = GL_UnlockTexture;
+    renderer->DirtyTexture = GL_DirtyTexture;
+    renderer->RenderFill = GL_RenderFill;
+    renderer->RenderCopy = GL_RenderCopy;
+    renderer->RenderPresent = GL_RenderPresent;
+    renderer->DestroyTexture = GL_DestroyTexture;
+    renderer->DestroyRenderer = GL_DestroyRenderer;
+    renderer->info = GL_RenderDriver.info;
+    renderer->window = window->id;
+    renderer->driverdata = data;
+
+    renderer->info.flags =
+        (SDL_RENDERER_PRESENTDISCARD | SDL_RENDERER_ACCELERATED);
+
+    if (GL_LoadFunctions(data) < 0) {
+        GL_DestroyRenderer(renderer);
+        return NULL;
+    }
+
+    data->context = SDL_GL_CreateContext(window->id);
+    if (!data->context) {
+        GL_DestroyRenderer(renderer);
+        return NULL;
+    }
+    if (SDL_GL_MakeCurrent(window->id, data->context) < 0) {
+        GL_DestroyRenderer(renderer);
+        return NULL;
+    }
+#ifdef __MACOSX__
+    /* Enable multi-threaded rendering */
+    /* Disabled until Ryan finishes his VBO/PBO code...
+       CGLEnable(CGLGetCurrentContext(), kCGLCEMPEngine);
+     */
+#endif
+
+    if (flags & SDL_RENDERER_PRESENTVSYNC) {
+        SDL_GL_SetSwapInterval(1);
+    } else {
+        SDL_GL_SetSwapInterval(0);
+    }
+    if (SDL_GL_GetSwapInterval() > 0) {
+        renderer->info.flags |= SDL_RENDERER_PRESENTVSYNC;
+    }
+
+    if (SDL_GL_GetAttribute(SDL_GL_DOUBLEBUFFER, &doublebuffer) == 0) {
+        if (!doublebuffer) {
+            renderer->info.flags |= SDL_RENDERER_SINGLEBUFFER;
+        }
+    }
+
+    data->glGetIntegerv(GL_MAX_TEXTURE_SIZE, &value);
+    renderer->info.max_texture_width = value;
+    data->glGetIntegerv(GL_MAX_TEXTURE_SIZE, &value);
+    renderer->info.max_texture_height = value;
+
+    if (SDL_GL_ExtensionSupported("GL_ARB_texture_rectangle")
+        || SDL_GL_ExtensionSupported("GL_EXT_texture_rectangle")) {
+        data->GL_ARB_texture_rectangle_supported = SDL_TRUE;
+    }
+    if (SDL_GL_ExtensionSupported("GL_EXT_paletted_texture")) {
+        data->GL_EXT_paletted_texture_supported = SDL_TRUE;
+        data->glColorTableEXT =
+            (PFNGLCOLORTABLEEXTPROC) SDL_GL_GetProcAddress("glColorTableEXT");
+    } else {
+        /* Don't advertise support for 8-bit indexed texture format */
+        Uint32 i, j;
+        SDL_RendererInfo *info = &renderer->info;
+        for (i = 0, j = 0; i < info->num_texture_formats; ++i) {
+            if (info->texture_formats[i] != SDL_PIXELFORMAT_INDEX8) {
+                info->texture_formats[j++] = info->texture_formats[i];
+            }
+        }
+        --info->num_texture_formats;
+    }
+    if (SDL_GL_ExtensionSupported("GL_APPLE_texture_range")) {
+        data->glTextureRangeAPPLE =
+            (void (*)(GLenum, GLsizei, const GLvoid *))
+            SDL_GL_GetProcAddress("glTextureRangeAPPLE");
+    }
+
+    /* Set up parameters for rendering */
+    data->blendMode = -1;
+    data->scaleMode = -1;
+    data->glDisable(GL_DEPTH_TEST);
+    data->glDisable(GL_CULL_FACE);
+    if (data->GL_ARB_texture_rectangle_supported) {
+        data->glEnable(GL_TEXTURE_RECTANGLE_ARB);
+    } else {
+        data->glEnable(GL_TEXTURE_2D);
+    }
+    data->updateSize = SDL_TRUE;
+
+    return renderer;
+}
+
+static int
+GL_ActivateRenderer(SDL_Renderer * renderer)
+{
+    GL_RenderData *data = (GL_RenderData *) renderer->driverdata;
+    SDL_Window *window = SDL_GetWindowFromID(renderer->window);
+
+    if (SDL_GL_MakeCurrent(window->id, data->context) < 0) {
+        return -1;
+    }
+    if (data->updateSize) {
+        data->glMatrixMode(GL_PROJECTION);
+        data->glLoadIdentity();
+        data->glMatrixMode(GL_MODELVIEW);
+        data->glLoadIdentity();
+        data->glViewport(0, 0, window->w, window->h);
+        data->glOrtho(0.0, (GLdouble) window->w, (GLdouble) window->h, 0.0,
+                      0.0, 1.0);
+        data->updateSize = SDL_FALSE;
+    }
+    return 0;
+}
+
+static int
+GL_DisplayModeChanged(SDL_Renderer * renderer)
+{
+    GL_RenderData *data = (GL_RenderData *) renderer->driverdata;
+
+    data->updateSize = SDL_TRUE;
+    return 0;
+}
+
+static __inline__ int
+power_of_2(int input)
+{
+    int value = 1;
+
+    while (value < input) {
+        value <<= 1;
+    }
+    return value;
+}
+
+static int
+GL_CreateTexture(SDL_Renderer * renderer, SDL_Texture * texture)
+{
+    GL_RenderData *renderdata = (GL_RenderData *) renderer->driverdata;
+    SDL_Window *window = SDL_GetWindowFromID(renderer->window);
+    GL_TextureData *data;
+    GLint internalFormat;
+    GLenum format, type;
+    int texture_w, texture_h;
+    GLenum result;
+
+    switch (texture->format) {
+    case SDL_PIXELFORMAT_INDEX1LSB:
+    case SDL_PIXELFORMAT_INDEX1MSB:
+        internalFormat = GL_RGB;
+        format = GL_COLOR_INDEX;
+        type = GL_BITMAP;
+        break;
+    case SDL_PIXELFORMAT_INDEX8:
+        if (!renderdata->GL_EXT_paletted_texture_supported) {
+            SDL_SetError("Unsupported texture format");
+            return -1;
+        }
+        internalFormat = GL_COLOR_INDEX8_EXT;
+        format = GL_COLOR_INDEX;
+        type = GL_UNSIGNED_BYTE;
+        break;
+    case SDL_PIXELFORMAT_RGB332:
+        internalFormat = GL_R3_G3_B2;
+        format = GL_RGB;
+        type = GL_UNSIGNED_BYTE_3_3_2;
+        break;
+    case SDL_PIXELFORMAT_RGB444:
+        internalFormat = GL_RGB4;
+        format = GL_RGB;
+        type = GL_UNSIGNED_SHORT_4_4_4_4;
+        break;
+    case SDL_PIXELFORMAT_RGB555:
+        internalFormat = GL_RGB5;
+        format = GL_RGB;
+        type = GL_UNSIGNED_SHORT_5_5_5_1;
+        break;
+    case SDL_PIXELFORMAT_ARGB4444:
+        internalFormat = GL_RGBA4;
+        format = GL_BGRA;
+        type = GL_UNSIGNED_SHORT_4_4_4_4_REV;
+        break;
+    case SDL_PIXELFORMAT_ARGB1555:
+        internalFormat = GL_RGB5_A1;
+        format = GL_BGRA;
+        type = GL_UNSIGNED_SHORT_1_5_5_5_REV;
+        break;
+    case SDL_PIXELFORMAT_RGB565:
+        internalFormat = GL_RGB8;
+        format = GL_RGB;
+        type = GL_UNSIGNED_SHORT_5_6_5;
+        break;
+    case SDL_PIXELFORMAT_RGB24:
+        internalFormat = GL_RGB8;
+        format = GL_RGB;
+        type = GL_UNSIGNED_BYTE;
+        break;
+    case SDL_PIXELFORMAT_RGB888:
+        internalFormat = GL_RGB8;
+        format = GL_BGRA;
+        type = GL_UNSIGNED_BYTE;
+        break;
+    case SDL_PIXELFORMAT_BGR24:
+        internalFormat = GL_RGB8;
+        format = GL_BGR;
+        type = GL_UNSIGNED_BYTE;
+        break;
+    case SDL_PIXELFORMAT_BGR888:
+        internalFormat = GL_RGB8;
+        format = GL_RGBA;
+        type = GL_UNSIGNED_BYTE;
+        break;
+    case SDL_PIXELFORMAT_ARGB8888:
+#ifdef __MACOSX__
+        internalFormat = GL_RGBA;
+        format = GL_BGRA;
+        type = GL_UNSIGNED_INT_8_8_8_8_REV;
+#else
+        internalFormat = GL_RGBA8;
+        format = GL_BGRA;
+        type = GL_UNSIGNED_BYTE;
+#endif
+        break;
+    case SDL_PIXELFORMAT_ABGR8888:
+        internalFormat = GL_RGBA8;
+        format = GL_RGBA;
+        type = GL_UNSIGNED_BYTE;
+        break;
+    case SDL_PIXELFORMAT_ARGB2101010:
+        internalFormat = GL_RGB10_A2;
+        format = GL_BGRA;
+        type = GL_UNSIGNED_INT_2_10_10_10_REV;
+        break;
+    default:
+        SDL_SetError("Unsupported texture format");
+        return -1;
+    }
+
+    data = (GL_TextureData *) SDL_calloc(1, sizeof(*data));
+    if (!data) {
+        SDL_OutOfMemory();
+        return -1;
+    }
+
+    if (texture->format == SDL_PIXELFORMAT_INDEX8) {
+        data->palette = (Uint8 *) SDL_malloc(3 * 256 * sizeof(Uint8));
+        if (!data->palette) {
+            SDL_OutOfMemory();
+            SDL_free(data);
+            return -1;
+        }
+        SDL_memset(data->palette, 0xFF, 3 * 256 * sizeof(Uint8));
+    }
+
+    if (texture->access == SDL_TEXTUREACCESS_STREAMING) {
+        data->pitch = texture->w * SDL_BYTESPERPIXEL(texture->format);
+        data->pixels = SDL_malloc(texture->h * data->pitch);
+        if (!data->pixels) {
+            SDL_OutOfMemory();
+            SDL_free(data);
+            return -1;
+        }
+    }
+
+    texture->driverdata = data;
+
+    renderdata->glGetError();
+    renderdata->glGenTextures(1, &data->texture);
+    if (renderdata->GL_ARB_texture_rectangle_supported) {
+        data->type = GL_TEXTURE_RECTANGLE_ARB;
+        texture_w = texture->w;
+        texture_h = texture->h;
+        data->texw = (GLfloat) texture->w;
+        data->texh = (GLfloat) texture->h;
+    } else {
+        data->type = GL_TEXTURE_2D;
+        texture_w = power_of_2(texture->w);
+        texture_h = power_of_2(texture->h);
+        data->texw = (GLfloat) texture->w / texture_w;
+        data->texh = (GLfloat) texture->h / texture_h;
+    }
+    data->format = format;
+    data->formattype = type;
+    renderdata->glBindTexture(data->type, data->texture);
+    renderdata->glTexParameteri(data->type, GL_TEXTURE_MIN_FILTER,
+                                GL_NEAREST);
+    renderdata->glTexParameteri(data->type, GL_TEXTURE_MAG_FILTER,
+                                GL_NEAREST);
+    renderdata->glTexParameteri(data->type, GL_TEXTURE_WRAP_S,
+                                GL_CLAMP_TO_EDGE);
+    renderdata->glTexParameteri(data->type, GL_TEXTURE_WRAP_T,
+                                GL_CLAMP_TO_EDGE);
+#ifdef __MACOSX__
+#ifndef GL_TEXTURE_STORAGE_HINT_APPLE
+#define GL_TEXTURE_STORAGE_HINT_APPLE       0x85BC
+#endif
+#ifndef STORAGE_CACHED_APPLE
+#define STORAGE_CACHED_APPLE                0x85BE
+#endif
+#ifndef STORAGE_SHARED_APPLE
+#define STORAGE_SHARED_APPLE                0x85BF
+#endif
+    if (texture->access == SDL_TEXTUREACCESS_STREAMING) {
+        renderdata->glTexParameteri(data->type, GL_TEXTURE_STORAGE_HINT_APPLE,
+                                    GL_STORAGE_SHARED_APPLE);
+    } else {
+        renderdata->glTexParameteri(data->type, GL_TEXTURE_STORAGE_HINT_APPLE,
+                                    GL_STORAGE_CACHED_APPLE);
+    }
+    if (texture->access == SDL_TEXTUREACCESS_STREAMING
+        && texture->format == SDL_PIXELFORMAT_ARGB8888) {
+        /*
+           if (renderdata->glTextureRangeAPPLE) {
+           renderdata->glTextureRangeAPPLE(data->type,
+           texture->h * data->pitch,
+           data->pixels);
+           }
+         */
+        renderdata->glPixelStorei(GL_UNPACK_CLIENT_STORAGE_APPLE, GL_TRUE);
+        renderdata->glTexImage2D(data->type, 0, internalFormat, texture_w,
+                                 texture_h, 0, format, type, data->pixels);
+    } else
+#endif
+    {
+        renderdata->glTexImage2D(data->type, 0, internalFormat, texture_w,
+                                 texture_h, 0, format, type, NULL);
+    }
+    result = renderdata->glGetError();
+    if (result != GL_NO_ERROR) {
+        GL_SetError("glTexImage2D()", result);
+        return -1;
+    }
+    return 0;
+}
+
+static int
+GL_QueryTexturePixels(SDL_Renderer * renderer, SDL_Texture * texture,
+                      void **pixels, int *pitch)
+{
+    GL_TextureData *data = (GL_TextureData *) texture->driverdata;
+
+    *pixels = data->pixels;
+    *pitch = data->pitch;
+    return 0;
+}
+
+static int
+GL_SetTexturePalette(SDL_Renderer * renderer, SDL_Texture * texture,
+                     const SDL_Color * colors, int firstcolor, int ncolors)
+{
+    GL_RenderData *renderdata = (GL_RenderData *) renderer->driverdata;
+    GL_TextureData *data = (GL_TextureData *) texture->driverdata;
+    Uint8 *palette;
+
+    if (!data->palette) {
+        SDL_SetError("Texture doesn't have a palette");
+        return -1;
+    }
+    palette = data->palette + firstcolor * 3;
+    while (ncolors--) {
+        *palette++ = colors->r;
+        *palette++ = colors->g;
+        *palette++ = colors->b;
+        ++colors;
+    }
+    renderdata->glBindTexture(data->type, data->texture);
+    renderdata->glColorTableEXT(data->type, GL_RGB8, 256, GL_RGB,
+                                GL_UNSIGNED_BYTE, data->palette);
+    return 0;
+}
+
+static int
+GL_GetTexturePalette(SDL_Renderer * renderer, SDL_Texture * texture,
+                     SDL_Color * colors, int firstcolor, int ncolors)
+{
+    GL_RenderData *renderdata = (GL_RenderData *) renderer->driverdata;
+    GL_TextureData *data = (GL_TextureData *) texture->driverdata;
+    Uint8 *palette;
+
+    if (!data->palette) {
+        SDL_SetError("Texture doesn't have a palette");
+        return -1;
+    }
+    palette = data->palette + firstcolor * 3;
+    while (ncolors--) {
+        colors->r = *palette++;
+        colors->g = *palette++;
+        colors->b = *palette++;
+        colors->unused = SDL_ALPHA_OPAQUE;
+        ++colors;
+    }
+    return 0;
+}
+
+static void
+SetupTextureUpdate(GL_RenderData * renderdata, SDL_Texture * texture,
+                   int pitch)
+{
+    if (texture->format == SDL_PIXELFORMAT_INDEX1LSB) {
+        renderdata->glPixelStorei(GL_UNPACK_LSB_FIRST, 1);
+    } else if (texture->format == SDL_PIXELFORMAT_INDEX1MSB) {
+        renderdata->glPixelStorei(GL_UNPACK_LSB_FIRST, 0);
+    }
+    renderdata->glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+    renderdata->glPixelStorei(GL_UNPACK_ROW_LENGTH,
+                              pitch / SDL_BYTESPERPIXEL(texture->format));
+}
+
+static int
+GL_SetTextureColorMod(SDL_Renderer * renderer, SDL_Texture * texture)
+{
+    return 0;
+}
+
+static int
+GL_SetTextureAlphaMod(SDL_Renderer * renderer, SDL_Texture * texture)
+{
+    return 0;
+}
+
+static int
+GL_SetTextureBlendMode(SDL_Renderer * renderer, SDL_Texture * texture)
+{
+    switch (texture->blendMode) {
+    case SDL_TEXTUREBLENDMODE_NONE:
+    case SDL_TEXTUREBLENDMODE_MASK:
+    case SDL_TEXTUREBLENDMODE_BLEND:
+    case SDL_TEXTUREBLENDMODE_ADD:
+    case SDL_TEXTUREBLENDMODE_MOD:
+        return 0;
+    default:
+        SDL_Unsupported();
+        texture->blendMode = SDL_TEXTUREBLENDMODE_NONE;
+        return -1;
+    }
+}
+
+static int
+GL_SetTextureScaleMode(SDL_Renderer * renderer, SDL_Texture * texture)
+{
+    switch (texture->scaleMode) {
+    case SDL_TEXTURESCALEMODE_NONE:
+    case SDL_TEXTURESCALEMODE_FAST:
+    case SDL_TEXTURESCALEMODE_SLOW:
+        return 0;
+    case SDL_TEXTURESCALEMODE_BEST:
+        SDL_Unsupported();
+        texture->scaleMode = SDL_TEXTURESCALEMODE_SLOW;
+        return -1;
+    default:
+        SDL_Unsupported();
+        texture->scaleMode = SDL_TEXTURESCALEMODE_NONE;
+        return -1;
+    }
+}
+
+static int
+GL_UpdateTexture(SDL_Renderer * renderer, SDL_Texture * texture,
+                 const SDL_Rect * rect, const void *pixels, int pitch)
+{
+    GL_RenderData *renderdata = (GL_RenderData *) renderer->driverdata;
+    GL_TextureData *data = (GL_TextureData *) texture->driverdata;
+    GLenum result;
+
+    renderdata->glGetError();
+    SetupTextureUpdate(renderdata, texture, pitch);
+    renderdata->glBindTexture(data->type, data->texture);
+    renderdata->glTexSubImage2D(data->type, 0, rect->x, rect->y, rect->w,
+                                rect->h, data->format, data->formattype,
+                                pixels);
+    result = renderdata->glGetError();
+    if (result != GL_NO_ERROR) {
+        GL_SetError("glTexSubImage2D()", result);
+        return -1;
+    }
+    return 0;
+}
+
+static int
+GL_LockTexture(SDL_Renderer * renderer, SDL_Texture * texture,
+               const SDL_Rect * rect, int markDirty, void **pixels,
+               int *pitch)
+{
+    GL_TextureData *data = (GL_TextureData *) texture->driverdata;
+
+    if (markDirty) {
+        SDL_AddDirtyRect(&data->dirty, rect);
+    }
+
+    *pixels =
+        (void *) ((Uint8 *) data->pixels + rect->y * data->pitch +
+                  rect->x * SDL_BYTESPERPIXEL(texture->format));
+    *pitch = data->pitch;
+    return 0;
+}
+
+static void
+GL_UnlockTexture(SDL_Renderer * renderer, SDL_Texture * texture)
+{
+}
+
+static void
+GL_DirtyTexture(SDL_Renderer * renderer, SDL_Texture * texture, int numrects,
+                const SDL_Rect * rects)
+{
+    GL_TextureData *data = (GL_TextureData *) texture->driverdata;
+    int i;
+
+    for (i = 0; i < numrects; ++i) {
+        SDL_AddDirtyRect(&data->dirty, &rects[i]);
+    }
+}
+
+static int
+GL_RenderFill(SDL_Renderer * renderer, Uint8 r, Uint8 g, Uint8 b, Uint8 a,
+              const SDL_Rect * rect)
+{
+    GL_RenderData *data = (GL_RenderData *) renderer->driverdata;
+    SDL_Window *window = SDL_GetWindowFromID(renderer->window);
+
+    data->glClearColor((GLclampf) r * inv255f, (GLclampf) g * inv255f,
+                       (GLclampf) b * inv255f, (GLclampf) a * inv255f);
+    data->glViewport(rect->x, window->h - rect->y, rect->w, rect->h);
+    data->glClear(GL_COLOR_BUFFER_BIT);
+    data->glViewport(0, 0, window->w, window->h);
+    return 0;
+}
+
+static int
+GL_RenderCopy(SDL_Renderer * renderer, SDL_Texture * texture,
+              const SDL_Rect * srcrect, const SDL_Rect * dstrect)
+{
+    GL_RenderData *data = (GL_RenderData *) renderer->driverdata;
+    GL_TextureData *texturedata = (GL_TextureData *) texture->driverdata;
+    int minx, miny, maxx, maxy;
+    GLfloat minu, maxu, minv, maxv;
+
+    if (texturedata->dirty.list) {
+        SDL_DirtyRect *dirty;
+        void *pixels;
+        int bpp = SDL_BYTESPERPIXEL(texture->format);
+        int pitch = texturedata->pitch;
+
+        SetupTextureUpdate(data, texture, pitch);
+        data->glBindTexture(texturedata->type, texturedata->texture);
+        for (dirty = texturedata->dirty.list; dirty; dirty = dirty->next) {
+            SDL_Rect *rect = &dirty->rect;
+            pixels =
+                (void *) ((Uint8 *) texturedata->pixels + rect->y * pitch +
+                          rect->x * bpp);
+            data->glTexSubImage2D(texturedata->type, 0, rect->x, rect->y,
+                                  rect->w, rect->h, texturedata->format,
+                                  texturedata->formattype, pixels);
+        }
+        SDL_ClearDirtyRects(&texturedata->dirty);
+    }
+
+    minx = dstrect->x;
+    miny = dstrect->y;
+    maxx = dstrect->x + dstrect->w;
+    maxy = dstrect->y + dstrect->h;
+
+    minu = (GLfloat) srcrect->x / texture->w;
+    minu *= texturedata->texw;
+    maxu = (GLfloat) (srcrect->x + srcrect->w) / texture->w;
+    maxu *= texturedata->texw;
+    minv = (GLfloat) srcrect->y / texture->h;
+    minv *= texturedata->texh;
+    maxv = (GLfloat) (srcrect->y + srcrect->h) / texture->h;
+    maxv *= texturedata->texh;
+
+    data->glBindTexture(texturedata->type, texturedata->texture);
+
+    if (texture->modMode) {
+        data->glColor4f((GLfloat) texture->r * inv255f,
+                        (GLfloat) texture->g * inv255f,
+                        (GLfloat) texture->b * inv255f,
+                        (GLfloat) texture->a * inv255f);
+    } else {
+        data->glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
+    }
+
+    if (texture->blendMode != data->blendMode) {
+        switch (texture->blendMode) {
+        case SDL_TEXTUREBLENDMODE_NONE:
+            data->glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
+            data->glDisable(GL_BLEND);
+            break;
+        case SDL_TEXTUREBLENDMODE_MASK:
+        case SDL_TEXTUREBLENDMODE_BLEND:
+            data->glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+            data->glEnable(GL_BLEND);
+            data->glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+            break;
+        case SDL_TEXTUREBLENDMODE_ADD:
+            data->glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+            data->glEnable(GL_BLEND);
+            data->glBlendFunc(GL_SRC_ALPHA, GL_ONE);
+            break;
+        case SDL_TEXTUREBLENDMODE_MOD:
+            data->glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+            data->glEnable(GL_BLEND);
+            data->glBlendFunc(GL_ZERO, GL_SRC_COLOR);
+            break;
+        }
+        data->blendMode = texture->blendMode;
+    }
+
+    if (texture->scaleMode != data->scaleMode) {
+        switch (texture->scaleMode) {
+        case SDL_TEXTURESCALEMODE_NONE:
+        case SDL_TEXTURESCALEMODE_FAST:
+            data->glTexParameteri(texturedata->type, GL_TEXTURE_MIN_FILTER,
+                                  GL_NEAREST);
+            data->glTexParameteri(texturedata->type, GL_TEXTURE_MAG_FILTER,
+                                  GL_NEAREST);
+            break;
+        case SDL_TEXTURESCALEMODE_SLOW:
+        case SDL_TEXTURESCALEMODE_BEST:
+            data->glTexParameteri(texturedata->type, GL_TEXTURE_MIN_FILTER,
+                                  GL_LINEAR);
+            data->glTexParameteri(texturedata->type, GL_TEXTURE_MAG_FILTER,
+                                  GL_LINEAR);
+            break;
+        }
+        data->scaleMode = texture->scaleMode;
+    }
+
+    data->glBegin(GL_TRIANGLE_STRIP);
+    data->glTexCoord2f(minu, minv);
+    data->glVertex2i(minx, miny);
+    data->glTexCoord2f(maxu, minv);
+    data->glVertex2i(maxx, miny);
+    data->glTexCoord2f(minu, maxv);
+    data->glVertex2i(minx, maxy);
+    data->glTexCoord2f(maxu, maxv);
+    data->glVertex2i(maxx, maxy);
+    data->glEnd();
+
+    return 0;
+}
+
+static void
+GL_RenderPresent(SDL_Renderer * renderer)
+{
+    SDL_GL_SwapWindow(renderer->window);
+}
+
+static void
+GL_DestroyTexture(SDL_Renderer * renderer, SDL_Texture * texture)
+{
+    GL_RenderData *renderdata = (GL_RenderData *) renderer->driverdata;
+    GL_TextureData *data = (GL_TextureData *) texture->driverdata;
+
+    if (!data) {
+        return;
+    }
+    if (data->texture) {
+        renderdata->glDeleteTextures(1, &data->texture);
+    }
+    if (data->palette) {
+        SDL_free(data->palette);
+    }
+    if (data->pixels) {
+        SDL_free(data->pixels);
+    }
+    SDL_FreeDirtyRects(&data->dirty);
+    SDL_free(data);
+    texture->driverdata = NULL;
+}
+
+static void
+GL_DestroyRenderer(SDL_Renderer * renderer)
+{
+    GL_RenderData *data = (GL_RenderData *) renderer->driverdata;
+
+    if (data) {
+        if (data->context) {
+            /* SDL_GL_MakeCurrent(0, NULL); *//* doesn't do anything */
+            SDL_GL_DeleteContext(data->context);
+        }
+        SDL_free(data);
+    }
+    SDL_free(renderer);
+}
+
+#endif /* SDL_VIDEO_RENDER_OGL */
+
+/* vi: set ts=4 sw=4 expandtab: */