Merge pull request #2713 from secondlife/v-2638

Don't clear big render target if all pixels will be replaced

1 files changed, 8 insertions, 1 deletions

diff --git a/indra/llrender/llrendertarget.h b/indra/llrender/llrendertarget.h
index cd3290cf66..f066534cf4 100644
--- a/indra/llrender/llrendertarget.h
+++ b/indra/llrender/llrendertarget.h
@@ -63,6 +63,7 @@ class LLRenderTarget
 public:
     // Whether or not to use FBO implementation
     static bool sUseFBO;
+    static bool sClearOnInvalidate;
     static U32 sBytesAllocated;
     static U32 sCurFBO;
     static U32 sCurResX;
@@ -128,11 +129,17 @@ public:
     //  Asserts that this target is not currently bound in the stack
     void bindTarget();
 
-    //clear render targer, clears depth buffer if present,
+    //clear render target, clears depth buffer if present,
     //uses scissor rect if in copy-to-texture mode
     // asserts that this target is currently bound
     void clear(U32 mask = 0xFFFFFFFF);
 
+    //same as clear, except may be a no-op depending on configuration
+    //useful to indicate the buffer is about to be overwritten and we
+    //don't care about its previous contents
+    //depending on the GPU, one may be more expensive than the other
+    void invalidate(U32 mask = 0xFFFFFFFF);
+
     //get applied viewport
     void getViewport(S32* viewport);