BGE: Setting up the RAS_ICanvas interface as the primary way to alter the OpenGL

viewport. This helps to eliminate OpenGL calls in weird places like the physics
code and to reduce glGet calls, which are expensive.

There should be no functional changes (except maybe a very slight speed improvement).

2 files changed, 8 insertions, 2 deletions

diff --git a/source/gameengine/Rasterizer/RAS_2DFilterManager.cpp b/source/gameengine/Rasterizer/RAS_2DFilterManager.cpp
index 7312b521788..0ae8908e946 100644
--- a/source/gameengine/Rasterizer/RAS_2DFilterManager.cpp
+++ b/source/gameengine/Rasterizer/RAS_2DFilterManager.cpp
@@ -398,8 +398,7 @@ void RAS_2DFilterManager::RenderFilters(RAS_ICanvas* canvas)
 	if (num_filters <= 0)
 		return;
 
-	GLuint	viewport[4]={0};
-	glGetIntegerv(GL_VIEWPORT,(GLint *)viewport);
+	const GLint *viewport = canvas->GetViewPort();
 	RAS_Rect rect = canvas->GetWindowArea();
 	int rect_width = rect.GetWidth()+1, rect_height = rect.GetHeight()+1;
 
diff --git a/source/gameengine/Rasterizer/RAS_ICanvas.h b/source/gameengine/Rasterizer/RAS_ICanvas.h
index 713a06845ac..f045eb7e423 100644
--- a/source/gameengine/Rasterizer/RAS_ICanvas.h
+++ b/source/gameengine/Rasterizer/RAS_ICanvas.h
@@ -180,6 +180,13 @@ public:
 		int x2, int y2
 	) = 0; 
 
+	/**
+	 * Get the visible viewport
+	 */
+	virtual
+		const int*
+	GetViewPort() = 0;
+
 	virtual 
 		void 
 	SetMouseState(