From 1ee51f2d88b8b000e80c2be6f5fda01ade62a570 Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Wed, 6 May 2026 12:30:46 -0400
Subject: [PATCH] opengles2: Rework render targets.
Now this keeps one FBO for each SDL_TEXTUREACCESS_TARGET texture, and doesn't
reuse it. We check if the FBO is "complete" once, at creation time, and
setting a render target merely has to bind the right FBO and never look back.
This simplifies the code and removes a guaranteed pipeline stall when setting
a new render target.
Fixes #15524.
(cherry picked from commit 56e0d052f18938e8d9c6cfe11d87d118afc1990d)
---
src/render/opengles2/SDL_render_gles2.c | 81 ++++++++-----------------
1 file changed, 24 insertions(+), 57 deletions(-)
diff --git a/src/render/opengles2/SDL_render_gles2.c b/src/render/opengles2/SDL_render_gles2.c
index 8f4dc4eb564b8..a37f2b1b74174 100644
--- a/src/render/opengles2/SDL_render_gles2.c
+++ b/src/render/opengles2/SDL_render_gles2.c
@@ -54,15 +54,6 @@
* Context structures *
*************************************************************************************************/
-typedef struct GLES2_FBOList GLES2_FBOList;
-
-struct GLES2_FBOList
-{
- Uint32 w, h;
- GLuint FBO;
- GLES2_FBOList *next;
-};
-
typedef struct
{
GLuint texture;
@@ -71,6 +62,7 @@ typedef struct
typedef struct
{
GLuint texture;
+ GLuint fbo; // framebuffer object; this is zero unless this texture is a render target.
bool texture_external;
GLenum texture_type;
GLenum pixel_format;
@@ -90,7 +82,6 @@ typedef struct
SDL_ScaleMode texture_scale_mode;
SDL_TextureAddressMode texture_address_mode_u;
SDL_TextureAddressMode texture_address_mode_v;
- GLES2_FBOList *fbo;
} GLES2_TextureData;
typedef enum
@@ -193,7 +184,6 @@ typedef struct GLES2_RenderData
#define SDL_PROC(ret, func, params) ret (APIENTRY *func) params;
#include "SDL_gles2funcs.h"
#undef SDL_PROC
- GLES2_FBOList *framebuffers;
GLuint window_framebuffer;
GLuint shader_id_cache[GLES2_SHADER_COUNT];
@@ -301,23 +291,6 @@ static bool GLES2_LoadFunctions(GLES2_RenderData *data)
return true;
}
-static GLES2_FBOList *GLES2_GetFBO(GLES2_RenderData *data, Uint32 w, Uint32 h)
-{
- GLES2_FBOList *result = data->framebuffers;
- while ((result) && ((result->w != w) || (result->h != h))) {
- result = result->next;
- }
- if (!result) {
- result = (GLES2_FBOList *)SDL_malloc(sizeof(GLES2_FBOList));
- result->w = w;
- result->h = h;
- data->glGenFramebuffers(1, &result->FBO);
- result->next = data->framebuffers;
- data->framebuffers = result;
- }
- return result;
-}
-
static bool GLES2_ActivateRenderer(SDL_Renderer *renderer)
{
GLES2_RenderData *data = (GLES2_RenderData *)renderer->internal;
@@ -1685,14 +1658,6 @@ static void GLES2_DestroyRenderer(SDL_Renderer *renderer)
}
if (data->context) {
- while (data->framebuffers) {
- GLES2_FBOList *nextnode = data->framebuffers->next;
- data->glDeleteFramebuffers(1, &data->framebuffers->FBO);
- GL_CheckError("", renderer);
- SDL_free(data->framebuffers);
- data->framebuffers = nextnode;
- }
-
#if USE_VERTEX_BUFFER_OBJECTS
data->glDeleteBuffers(SDL_arraysize(data->vertex_buffers), data->vertex_buffers);
GL_CheckError("", renderer);
@@ -1956,6 +1921,11 @@ static bool GLES2_CreateTexture(SDL_Renderer *renderer, SDL_Texture *texture, SD
if (texture->format != SDL_PIXELFORMAT_EXTERNAL_OES) {
renderdata->glTexImage2D(data->texture_type, 0, format, texture->w, texture->h, 0, format, type, NULL);
if (!GL_CheckError("glTexImage2D()", renderer)) {
+ if (!data->texture_external) {
+ renderdata->glDeleteTextures(1, &data->texture);
+ }
+ SDL_free(data->pixel_data);
+ SDL_free(data);
return false;
}
}
@@ -1965,9 +1935,20 @@ static bool GLES2_CreateTexture(SDL_Renderer *renderer, SDL_Texture *texture, SD
SDL_SetNumberProperty(SDL_GetTextureProperties(texture), SDL_PROP_TEXTURE_OPENGLES2_TEXTURE_TARGET_NUMBER, data->texture_type);
if (texture->access == SDL_TEXTUREACCESS_TARGET) {
- data->fbo = GLES2_GetFBO((GLES2_RenderData *)renderer->internal, texture->w, texture->h);
- } else {
- data->fbo = NULL;
+ renderdata->glGenFramebuffers(1, &data->fbo);
+ renderdata->glBindFramebuffer(GL_FRAMEBUFFER, data->fbo);
+ renderdata->glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, data->texture_type, data->texture, 0);
+ const GLenum status = renderdata->glCheckFramebufferStatus(GL_FRAMEBUFFER);
+ renderdata->glBindFramebuffer(GL_FRAMEBUFFER, renderer->target ? ((GLES2_TextureData *)renderer->target->internal)->fbo : renderdata->window_framebuffer); // rebind previous fbo.
+ if (status != GL_FRAMEBUFFER_COMPLETE) {
+ renderdata->glDeleteFramebuffers(1, &data->fbo);
+ if (!data->texture_external) {
+ renderdata->glDeleteTextures(1, &data->texture);
+ }
+ SDL_free(data->pixel_data);
+ SDL_free(data);
+ return SDL_SetError("Texture framebuffer was incomplete");
+ }
}
return GL_CheckError("", renderer);
@@ -2206,24 +2187,8 @@ static void GLES2_UnlockTexture(SDL_Renderer *renderer, SDL_Texture *texture)
static bool GLES2_SetRenderTarget(SDL_Renderer *renderer, SDL_Texture *texture)
{
GLES2_RenderData *data = (GLES2_RenderData *)renderer->internal;
- GLES2_TextureData *texturedata = NULL;
- GLenum status;
-
data->drawstate.viewport_dirty = true;
-
- if (!texture) {
- data->glBindFramebuffer(GL_FRAMEBUFFER, data->window_framebuffer);
- } else {
- texturedata = (GLES2_TextureData *)texture->internal;
- data->glBindFramebuffer(GL_FRAMEBUFFER, texturedata->fbo->FBO);
- // TODO: check if texture pixel format allows this operation
- data->glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, texturedata->texture_type, texturedata->texture, 0);
- // Check FBO status
- status = data->glCheckFramebufferStatus(GL_FRAMEBUFFER);
- if (status != GL_FRAMEBUFFER_COMPLETE) {
- return SDL_SetError("glFramebufferTexture2D() failed");
- }
- }
+ data->glBindFramebuffer(GL_FRAMEBUFFER, texture ? ((GLES2_TextureData *)texture->internal)->fbo : data->window_framebuffer);
return true;
}
@@ -2244,6 +2209,9 @@ static void GLES2_DestroyTexture(SDL_Renderer *renderer, SDL_Texture *texture)
// Destroy the texture
if (tdata) {
+ if (tdata->fbo) {
+ data->glDeleteFramebuffers(1, &tdata->fbo);
+ }
if (tdata->texture && !tdata->texture_external) {
data->glDeleteTextures(1, &tdata->texture);
}
@@ -2433,7 +2401,6 @@ static bool GLES2_CreateRenderer(SDL_Renderer *renderer, SDL_Window *window, SDL
data->glGenBuffers(SDL_arraysize(data->vertex_buffers), data->vertex_buffers);
#endif
- data->framebuffers = NULL;
data->glGetIntegerv(GL_FRAMEBUFFER_BINDING, &window_framebuffer);
data->window_framebuffer = (GLuint)window_framebuffer;