Fix framebuffer completeness being broken after last framebuffer cleanup

commits.

Basically, we don't set a draw buffer until draw time comes. Also add
explicit validation function to validate after all textures have been
attached (could be done automatically at bind time too probably, but
left out for now)

3 files changed, 51 insertions, 9 deletions

diff --git a/source/blender/gpu/GPU_extensions.h b/source/blender/gpu/GPU_extensions.h
index b2378f0dae6..bb0cf2dd2b9 100644
--- a/source/blender/gpu/GPU_extensions.h
+++ b/source/blender/gpu/GPU_extensions.h
@@ -148,6 +148,7 @@ void GPU_framebuffer_texture_detach(GPUTexture *tex);
 void GPU_framebuffer_slot_bind(GPUFrameBuffer *fb, int slot);
 void GPU_framebuffer_texture_unbind(GPUFrameBuffer *fb, GPUTexture *tex);
 void GPU_framebuffer_free(GPUFrameBuffer *fb);
+bool GPU_framebuffer_check_valid(GPUFrameBuffer *fb, char err_out[256]);
 
 void GPU_framebuffer_restore(void);
 void GPU_framebuffer_blur(GPUFrameBuffer *fb, GPUTexture *tex, GPUFrameBuffer *blurfb, GPUTexture *blurtex);
diff --git a/source/blender/gpu/intern/gpu_extensions.c b/source/blender/gpu/intern/gpu_extensions.c
index 37a787be20e..faec3cc3481 100644
--- a/source/blender/gpu/intern/gpu_extensions.c
+++ b/source/blender/gpu/intern/gpu_extensions.c
@@ -866,12 +866,17 @@ GPUFrameBuffer *GPU_framebuffer_create(void)
 		return NULL;
 	}
 
+	/* make sure no read buffer is enabled, so completeness check will not fail. We set those at binding time */
+	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fb->object);
+	glReadBuffer(GL_NONE);
+	glDrawBuffer(GL_NONE);
+	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+	
 	return fb;
 }
 
 int GPU_framebuffer_texture_attach(GPUFrameBuffer *fb, GPUTexture *tex, int slot, char err_out[256])
 {
-	GLenum status;
 	GLenum attachment;
 	GLenum error;
 
@@ -906,14 +911,6 @@ int GPU_framebuffer_texture_attach(GPUFrameBuffer *fb, GPUTexture *tex, int slot
 		return 0;
 	}
 
-	status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
-
-	if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
-		GPU_framebuffer_restore();
-		GPU_print_framebuffer_error(status, err_out);
-		return 0;
-	}
-
 	if (tex->depth)
 		fb->depthtex = tex;
 	else
@@ -1026,6 +1023,29 @@ void GPU_framebuffer_texture_unbind(GPUFrameBuffer *UNUSED(fb), GPUTexture *UNUS
 	glPopAttrib();
 }
 
+
+bool GPU_framebuffer_check_valid(GPUFrameBuffer *fb, char err_out[256])
+{
+	GLenum status;
+	
+	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fb->object);
+	GG.currentfb = fb->object;
+	
+	/* Clean glError buffer. */
+	while (glGetError() != GL_NO_ERROR) {}
+	
+	status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
+	
+	if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
+		GPU_framebuffer_restore();
+		GPU_print_framebuffer_error(status, err_out);
+		return false;
+	}
+	
+	return true;
+}
+
+
 void GPU_framebuffer_free(GPUFrameBuffer *fb)
 {
 	int i;
@@ -1162,6 +1182,12 @@ GPUOffScreen *GPU_offscreen_create(int width, int height, char err_out[256])
 		GPU_offscreen_free(ofs);
 		return NULL;
 	}
+	
+	/* check validity at the very end! */
+	if (!GPU_framebuffer_check_valid(ofs->fb, err_out)) {
+		GPU_offscreen_free(ofs);
+		return NULL;		
+	}
 
 	GPU_framebuffer_restore();
 
diff --git a/source/blender/gpu/intern/gpu_material.c b/source/blender/gpu/intern/gpu_material.c
index d6244b4255b..e4228bedf9d 100644
--- a/source/blender/gpu/intern/gpu_material.c
+++ b/source/blender/gpu/intern/gpu_material.c
@@ -1868,6 +1868,11 @@ GPULamp *GPU_lamp_from_blender(Scene *scene, Object *ob, Object *par)
 				return lamp;
 			}
 
+			if (!GPU_framebuffer_check_valid(lamp->fb, NULL)) {
+				gpu_lamp_shadow_free(lamp);
+				return lamp;				
+			}
+			
 			/* FBO and texture for blurring */
 			lamp->blurfb = GPU_framebuffer_create();
 			if (!lamp->blurfb) {
@@ -1885,6 +1890,11 @@ GPULamp *GPU_lamp_from_blender(Scene *scene, Object *ob, Object *par)
 				gpu_lamp_shadow_free(lamp);
 				return lamp;
 			}
+			
+			if (!GPU_framebuffer_check_valid(lamp->blurfb, NULL)) {
+				gpu_lamp_shadow_free(lamp);
+				return lamp;				
+			}			
 		}
 		else {
 			lamp->tex = GPU_texture_create_depth(lamp->size, lamp->size, NULL);
@@ -1897,6 +1907,11 @@ GPULamp *GPU_lamp_from_blender(Scene *scene, Object *ob, Object *par)
 				gpu_lamp_shadow_free(lamp);
 				return lamp;
 			}
+			
+			if (!GPU_framebuffer_check_valid(lamp->fb, NULL)) {
+				gpu_lamp_shadow_free(lamp);
+				return lamp;				
+			}						
 		}
 
 		GPU_framebuffer_restore();