GPUState: Move Scissor and Viewport state to framebuffer

This way it is way clearer what each viewport state is. There is
no more save and reset. The scissor test is also saved per
framebuffer.

The only rule to remember is that the viewport state (size and
origin) is reset for both the viewport and scissor when a texture
is attached or detached from an attachment slot.

1 files changed, 19 insertions, 14 deletions

diff --git a/source/blender/gpu/intern/gpu_framebuffer.cc b/source/blender/gpu/intern/gpu_framebuffer.cc
index 600dd129aef..f4b8a4040d4 100644
--- a/source/blender/gpu/intern/gpu_framebuffer.cc
+++ b/source/blender/gpu/intern/gpu_framebuffer.cc
@@ -55,6 +55,7 @@ FrameBuffer::FrameBuffer(const char *name)
   }
   /* Force config on first use. */
   dirty_attachments_ = true;
+  dirty_state_ = true;
 
   for (int i = 0; i < ARRAY_SIZE(attachments_); i++) {
     attachments_[i].tex = NULL;
@@ -341,21 +342,30 @@ void GPU_framebuffer_config_array(GPUFrameBuffer *gpu_fb,
   }
 }
 
-/* ---------- Framebuffer Operations ----------- */
+/* ---------- Viewport & Scissor Region ----------- */
 
-#define CHECK_FRAMEBUFFER_IS_BOUND(_fb) \
-  BLI_assert(GPU_framebuffer_bound(_fb)); \
-  UNUSED_VARS_NDEBUG(_fb); \
-  ((void)0)
+/* Viewport and scissor size is stored per framebuffer.
+ * It is only reset to its original dimensions explicitely OR when binding the framebuffer after
+ * modifiying its attachments. */
+void GPU_framebuffer_viewport_set(GPUFrameBuffer *gpu_fb, int x, int y, int width, int height)
+{
+  int viewport_rect[4] = {x, y, width, height};
+  reinterpret_cast<FrameBuffer *>(gpu_fb)->viewport_set(viewport_rect);
+}
 
-/* Needs to be done after binding. */
-void GPU_framebuffer_viewport_set(GPUFrameBuffer *gpu_fb, int x, int y, int w, int h)
+void GPU_framebuffer_viewport_get(GPUFrameBuffer *gpu_fb, int r_viewport[4])
 {
-  CHECK_FRAMEBUFFER_IS_BOUND(gpu_fb);
+  reinterpret_cast<FrameBuffer *>(gpu_fb)->viewport_get(r_viewport);
+}
 
-  GPU_viewport(x, y, w, h);
+/* Reset to its attachement(s) size. */
+void GPU_framebuffer_viewport_reset(GPUFrameBuffer *gpu_fb)
+{
+  reinterpret_cast<FrameBuffer *>(gpu_fb)->viewport_reset();
 }
 
+/* ---------- Framebuffer Operations ----------- */
+
 void GPU_framebuffer_clear(GPUFrameBuffer *gpu_fb,
                            eGPUFrameBufferBits buffers,
                            const float clear_col[4],
@@ -582,19 +592,14 @@ GPUOffScreen *GPU_offscreen_create(
     return NULL;
   }
 
-  int viewport[4];
-  GPU_viewport_size_get_i(viewport);
-
   GPUFrameBuffer *fb = gpu_offscreen_fb_get(ofs);
 
   /* check validity at the very end! */
   if (!GPU_framebuffer_check_valid(fb, err_out)) {
     GPU_offscreen_free(ofs);
-    GPU_viewport(UNPACK4(viewport));
     return NULL;
   }
   GPU_framebuffer_restore();
-  GPU_viewport(UNPACK4(viewport));
   return ofs;
 }