GPU: support default framebuffer with ID not equal to 0

4 files changed, 15 insertions, 13 deletions

diff --git a/source/blender/gpu/intern/gpu_context.cpp b/source/blender/gpu/intern/gpu_context.cpp
index 4bfc44327c2..a0e03e61d5d 100644
--- a/source/blender/gpu/intern/gpu_context.cpp
+++ b/source/blender/gpu/intern/gpu_context.cpp
@@ -64,6 +64,7 @@ static std::mutex orphans_mutex;
 
 struct GPUContext {
   GLuint default_vao;
+  GLuint default_framebuffer;
   GPUFrameBuffer *current_fbo;
   std::unordered_set<GPUBatch *> batches; /* Batches that have VAOs from this context */
 #ifdef DEBUG
@@ -137,11 +138,12 @@ static void orphans_clear(GPUContext *ctx)
   orphans_mutex.unlock();
 }
 
-GPUContext *GPU_context_create(void)
+GPUContext *GPU_context_create(GLuint default_framebuffer)
 {
   /* BLI_assert(thread_is_main()); */
   GPUContext *ctx = new GPUContext;
   glGenVertexArrays(1, &ctx->default_vao);
+  ctx->default_framebuffer = default_framebuffer;
   GPU_context_active_set(ctx);
   return ctx;
 }
@@ -201,6 +203,14 @@ GLuint GPU_vao_default(void)
   return active_ctx->default_vao;
 }
 
+GLuint GPU_framebuffer_default(void)
+{
+  BLI_assert(active_ctx); /* need at least an active context */
+  BLI_assert(pthread_equal(
+      pthread_self(), active_ctx->thread)); /* context has been activated by another thread! */
+  return active_ctx->default_framebuffer;
+}
+
 GLuint GPU_vao_alloc(void)
 {
   GLuint new_vao_id = 0;
diff --git a/source/blender/gpu/intern/gpu_context_private.h b/source/blender/gpu/intern/gpu_context_private.h
index 9c4cb30e40f..6825b67d2c8 100644
--- a/source/blender/gpu/intern/gpu_context_private.h
+++ b/source/blender/gpu/intern/gpu_context_private.h
@@ -35,6 +35,7 @@ extern "C" {
 struct GPUFrameBuffer;
 
 GLuint GPU_vao_default(void);
+GLuint GPU_framebuffer_default(void);
 
 /* These require a gl ctx bound. */
 GLuint GPU_buf_alloc(void);
diff --git a/source/blender/gpu/intern/gpu_extensions.c b/source/blender/gpu/intern/gpu_extensions.c
index 57734686b23..8cd554cc9d5 100644
--- a/source/blender/gpu/intern/gpu_extensions.c
+++ b/source/blender/gpu/intern/gpu_extensions.c
@@ -244,15 +244,6 @@ void gpu_extensions_init(void)
 
   glGetFloatv(GL_ALIASED_LINE_WIDTH_RANGE, GG.line_width_range);
 
-#ifndef NDEBUG
-  GLint ret;
-  glBindFramebuffer(GL_FRAMEBUFFER, 0);
-  glGetFramebufferAttachmentParameteriv(
-      GL_FRAMEBUFFER, GL_FRONT_LEFT, GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE, &ret);
-  /* We expect FRONT_LEFT to be the default buffer. */
-  BLI_assert(ret == GL_FRAMEBUFFER_DEFAULT);
-#endif
-
   glGetIntegerv(GL_MAX_COLOR_TEXTURE_SAMPLES, &GG.samples_color_texture_max);
 
   const char *vendor = (const char *)glGetString(GL_VENDOR);
diff --git a/source/blender/gpu/intern/gpu_framebuffer.c b/source/blender/gpu/intern/gpu_framebuffer.c
index 62fb02931ab..98ab6d96c0a 100644
--- a/source/blender/gpu/intern/gpu_framebuffer.c
+++ b/source/blender/gpu/intern/gpu_framebuffer.c
@@ -539,7 +539,7 @@ void GPU_framebuffer_bind(GPUFrameBuffer *fb)
 void GPU_framebuffer_restore(void)
 {
   if (GPU_framebuffer_active_get() != NULL) {
-    glBindFramebuffer(GL_FRAMEBUFFER, 0);
+    glBindFramebuffer(GL_FRAMEBUFFER, GPU_framebuffer_default());
     gpu_framebuffer_current_set(NULL);
   }
 }
@@ -718,7 +718,7 @@ void GPU_framebuffer_blit(GPUFrameBuffer *fb_read,
     gpu_framebuffer_current_set(prev_fb);
   }
   else {
-    glBindFramebuffer(GL_FRAMEBUFFER, 0);
+    glBindFramebuffer(GL_FRAMEBUFFER, GPU_framebuffer_default());
     gpu_framebuffer_current_set(NULL);
   }
 }
@@ -909,7 +909,7 @@ void GPU_offscreen_draw_to_screen(GPUOffScreen *ofs, int x, int y)
     gpu_print_framebuffer_error(status, NULL);
   }
 
-  glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
+  glBindFramebuffer(GL_READ_FRAMEBUFFER, GPU_framebuffer_default());
 }
 
 void GPU_offscreen_read_pixels(GPUOffScreen *ofs, int type, void *pixels)