Attempted fix for #27482: game engine running slow due to revision 36698 which

fixed frame colors for letterbox drawing (happens when in camera view).

Cause is unclear, seems some sort of strange graphics driver thing on 32 bit.
Changes are a fix for the incorrect usage of glViewport, and avoiding the extra
clear if it's not needed.

1 files changed, 11 insertions, 6 deletions

diff --git a/source/gameengine/BlenderRoutines/BL_KetsjiEmbedStart.cpp b/source/gameengine/BlenderRoutines/BL_KetsjiEmbedStart.cpp
index 59c5888ff35..d9017c6a4ca 100644
--- a/source/gameengine/BlenderRoutines/BL_KetsjiEmbedStart.cpp
+++ b/source/gameengine/BlenderRoutines/BL_KetsjiEmbedStart.cpp
@@ -250,10 +250,12 @@ extern "C" void StartKetsjiShell(struct bContext *C, struct ARegion *ar, rcti *c
 
 		// some blender stuff
 		float camzoom;
+		int draw_letterbox = 0;
 		
 		if(rv3d->persp==RV3D_CAMOB) {
 			if(startscene->gm.framing.type == SCE_GAMEFRAMING_BARS) { /* Letterbox */
 				camzoom = 1.0f;
+				draw_letterbox = 1;
 			}
 			else {
 				camzoom = BKE_screen_view3d_zoom_to_fac(rv3d->camzoom);
@@ -428,12 +430,15 @@ extern "C" void StartKetsjiShell(struct bContext *C, struct ARegion *ar, rcti *c
 					// first check if we want to exit
 					exitrequested = ketsjiengine->GetExitCode();
 
-					// Clear screen to border color
-					// We do this here since we set the canvas to be within the frames. This means the engine
-					// itself is unaware of the extra space, so we clear the whole region for it.
-					glClearColor(scene->gm.framing.col[0], scene->gm.framing.col[1], scene->gm.framing.col[2], 1.0f);
-					glViewport(ar->winrct.xmin, ar->winrct.ymin, ar->winrct.xmax, ar->winrct.ymax);
-					glClear(GL_COLOR_BUFFER_BIT);
+					if(draw_letterbox) {
+						// Clear screen to border color
+						// We do this here since we set the canvas to be within the frames. This means the engine
+						// itself is unaware of the extra space, so we clear the whole region for it.
+						glClearColor(scene->gm.framing.col[0], scene->gm.framing.col[1], scene->gm.framing.col[2], 1.0f);
+						glViewport(ar->winrct.xmin, ar->winrct.ymin,
+							ar->winrct.xmax - ar->winrct.xmin, ar->winrct.ymax - ar->winrct.ymin);
+						glClear(GL_COLOR_BUFFER_BIT);
+					}
 					
 					// kick the engine
 					bool render = ketsjiengine->NextFrame();