Fixed bug 3373 - OpenGL implementation differences of glDrawTexfOES
Simon Hug
It seems not everyone implemented glDrawTexfOES the same. Intel and Mesa ignore the viewport entirely, whereas the Raspberry Pi implementation offsets the coordinates and does viewport clipping.
The glDrawTexfOES extension text [1] for the function says "Xs and Ys are given directly in window (viewport) coordinates." I guess this wasn't clear enough.
Alex Szpakowski
Honestly I'd probably remove that codepath from SDL_Render entirely. It's an OpenGL ES 1-specific extension that isn't likely to give huge performance gains and adds additional maintenance overhead to SDL_Render while also having bugs in some drivers (as seen here).
diff --git a/src/render/opengles/SDL_render_gles.c b/src/render/opengles/SDL_render_gles.c
index 0d59da3..9f79691 100644
--- a/src/render/opengles/SDL_render_gles.c
+++ b/src/render/opengles/SDL_render_gles.c
@@ -129,8 +129,6 @@
GLES_FBOList *framebuffers;
GLuint window_framebuffer;
- SDL_bool useDrawTexture;
- SDL_bool GL_OES_draw_texture_supported;
SDL_bool GL_OES_blend_func_separate_supported;
} GLES_RenderData;
@@ -369,19 +367,6 @@
renderer->info.flags |= SDL_RENDERER_PRESENTVSYNC;
}
-#if SDL_VIDEO_DRIVER_PANDORA
- data->GL_OES_draw_texture_supported = SDL_FALSE;
- data->useDrawTexture = SDL_FALSE;
-#else
- if (SDL_GL_ExtensionSupported("GL_OES_draw_texture")) {
- data->GL_OES_draw_texture_supported = SDL_TRUE;
- data->useDrawTexture = SDL_TRUE;
- } else {
- data->GL_OES_draw_texture_supported = SDL_FALSE;
- data->useDrawTexture = SDL_FALSE;
- }
-#endif
-
value = 0;
data->glGetIntegerv(GL_MAX_TEXTURE_SIZE, &value);
renderer->info.max_texture_width = value;
@@ -952,71 +937,42 @@
GLES_SetTexCoords(data, SDL_TRUE);
- if (data->GL_OES_draw_texture_supported && data->useDrawTexture) {
- /* this code is a little funny because the viewport is upside down vs SDL's coordinate system */
- GLint cropRect[4];
- int w, h;
- SDL_Window *window = renderer->window;
+ minx = dstrect->x;
+ miny = dstrect->y;
+ maxx = dstrect->x + dstrect->w;
+ maxy = dstrect->y + dstrect->h;
- SDL_GetWindowSize(window, &w, &h);
- if (renderer->target) {
- cropRect[0] = srcrect->x;
- cropRect[1] = srcrect->y;
- cropRect[2] = srcrect->w;
- cropRect[3] = srcrect->h;
- data->glTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_CROP_RECT_OES,
- cropRect);
- data->glDrawTexfOES(renderer->viewport.x + dstrect->x, renderer->viewport.y + dstrect->y, 0,
- dstrect->w, dstrect->h);
- } else {
- cropRect[0] = srcrect->x;
- cropRect[1] = srcrect->y + srcrect->h;
- cropRect[2] = srcrect->w;
- cropRect[3] = -srcrect->h;
- data->glTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_CROP_RECT_OES,
- cropRect);
- data->glDrawTexfOES(renderer->viewport.x + dstrect->x,
- h - (renderer->viewport.y + dstrect->y) - dstrect->h, 0,
- dstrect->w, dstrect->h);
- }
- } else {
+ 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;
- minx = dstrect->x;
- miny = dstrect->y;
- maxx = dstrect->x + dstrect->w;
- maxy = dstrect->y + dstrect->h;
+ vertices[0] = minx;
+ vertices[1] = miny;
+ vertices[2] = maxx;
+ vertices[3] = miny;
+ vertices[4] = minx;
+ vertices[5] = maxy;
+ vertices[6] = maxx;
+ vertices[7] = maxy;
- 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;
+ texCoords[0] = minu;
+ texCoords[1] = minv;
+ texCoords[2] = maxu;
+ texCoords[3] = minv;
+ texCoords[4] = minu;
+ texCoords[5] = maxv;
+ texCoords[6] = maxu;
+ texCoords[7] = maxv;
- vertices[0] = minx;
- vertices[1] = miny;
- vertices[2] = maxx;
- vertices[3] = miny;
- vertices[4] = minx;
- vertices[5] = maxy;
- vertices[6] = maxx;
- vertices[7] = maxy;
+ data->glVertexPointer(2, GL_FLOAT, 0, vertices);
+ data->glTexCoordPointer(2, GL_FLOAT, 0, texCoords);
+ data->glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
- texCoords[0] = minu;
- texCoords[1] = minv;
- texCoords[2] = maxu;
- texCoords[3] = minv;
- texCoords[4] = minu;
- texCoords[5] = maxv;
- texCoords[6] = maxu;
- texCoords[7] = maxv;
-
- data->glVertexPointer(2, GL_FLOAT, 0, vertices);
- data->glTexCoordPointer(2, GL_FLOAT, 0, texCoords);
- data->glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
- }
data->glDisable(GL_TEXTURE_2D);
return 0;
