Merge lp:~vanvugt/nux/fix-1064834-3.0 into lp:nux/3.0

[Daniel van Vugt]

Remove a massive bottleneck, where almost all the CPU time was spent
loading a black image on texture creation. (LP: #1064834)

CPU time spent in glTexImage2D:
  Before: 93.54%
  After: 0.10%

Backported to Nux 3.x. Already committed to lp:nux.

[Timo Jyrinki (timo-jyrinki)]

Tested and works fine. As discussed in the bug report, it does not fix the root cause for Dash / blur slowness (drawing the Dash content), so at least I'm not still seeing a really smooth dash fade in on sandy bridge yet. On llvmpipe the benefit would be seen very clearly, but we have low graphics mode without active blur there already.

Anyway, a very welcome fix that might help a lot on some combinations of hardware for nux 3.0 users as well.

review: Approve

[Jay Taoko (jaytaoko)]

+1

review: Approve

=== modified file 'NuxGraphics/IOpenGLSurface.cpp'
--- NuxGraphics/IOpenGLSurface.cpp	2012-01-17 03:57:31 +0000
+++ NuxGraphics/IOpenGLSurface.cpp	2012-10-11 03:24:34 +0000
@@ -525,8 +525,6 @@
     nuxAssert( texheight > 0 ); // Should never happen
     nuxAssert( size > 0 ); // Should never happen
 
-    BYTE *DummyBuffer = (BYTE *) calloc(size, sizeof(BYTE));
-
     CHECKGL(glPixelStorei(GL_UNPACK_ALIGNMENT, MemAlignment));
 
 #ifndef NUX_OPENGLES_20
@@ -546,7 +544,7 @@
           texheight,
           0,                          // border
           size,                       // image Size
-          DummyBuffer                           // data
+          NULL                        // data
         );
         CHECKGL_MSG(glCompressedTexImage2DARB);
       }
@@ -580,7 +578,7 @@
           0,                          // border
           GPixelFormats[_BaseTexture->_PixelFormat].Format,
           GPixelFormats[_BaseTexture->_PixelFormat].type,
-          DummyBuffer);
+          NULL);
         CHECKGL_MSG(glTexImage2D);
 #ifndef NUX_OPENGLES_20
       }
@@ -602,9 +600,6 @@
     }
 #endif
 
-    free(DummyBuffer);
-
-
     //    { //[DEBUGGING - Red Texture]
     //        // This is going to put some red in the texture.
     //        // The texture is not compressed.