commit f98e63a54b8a230c0bdfd5c958f949764f3fdb73
author Geoff Lang <geofflang@chromium.org> Mon May 12 16:45:12 2014 -0400
committer Geoff Lang <geofflang@chromium.org> Thu May 15 13:40:00 2014 +0000
tree fe372815266c757f091fbfc0896403f87b02c873
parent 946b948d8e5faa2ce63af6a7850889be0eaba45f

Minimize the API calls done by InputLayoutCache::applyVertexBuffers.

Reduce the number of IASetInputLayout calls to 1 in all cases and set the
fewest number of buffers at once.

BUG=260069

Change-Id: I059337fc6601ecefd801ef37546935becaa0d355
Reviewed-on: https://chromium-review.googlesource.com/199345
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>

src/libGLESv2/renderer/d3d11/InputLayoutCache.cpp

diff --git a/src/libGLESv2/renderer/d3d11/InputLayoutCache.cpp b/src/libGLESv2/renderer/d3d11/InputLayoutCache.cpp
index 00cc0ed..6f53fd4 100644
--- a/src/libGLESv2/renderer/d3d11/InputLayoutCache.cpp
+++ b/src/libGLESv2/renderer/d3d11/InputLayoutCache.cpp
@@ -184,6 +184,9 @@
         mCurrentIL = inputLayout;
     }
 
+    bool dirtyBuffers = false;
+    size_t minDiff = gl::MAX_VERTEX_ATTRIBS;
+    size_t maxDiff = 0;
     for (unsigned int i = 0; i < gl::MAX_VERTEX_ATTRIBS; i++)
     {
         ID3D11Buffer *buffer = NULL;
@@ -203,13 +206,23 @@
         if (buffer != mCurrentBuffers[i] || vertexStride != mCurrentVertexStrides[i] ||
             vertexOffset != mCurrentVertexOffsets[i])
         {
-            mDeviceContext->IASetVertexBuffers(i, 1, &buffer, &vertexStride, &vertexOffset);
+            dirtyBuffers = true;
+            minDiff = std::min(minDiff, i);
+            maxDiff = std::max(maxDiff, i);
+
             mCurrentBuffers[i] = buffer;
             mCurrentVertexStrides[i] = vertexStride;
             mCurrentVertexOffsets[i] = vertexOffset;
         }
     }
 
+    if (dirtyBuffers)
+    {
+        ASSERT(minDiff <= maxDiff && maxDiff < gl::MAX_VERTEX_ATTRIBS);
+        mDeviceContext->IASetVertexBuffers(minDiff, maxDiff - minDiff + 1, mCurrentBuffers + minDiff,
+                                           mCurrentVertexStrides + minDiff, mCurrentVertexOffsets + minDiff);
+    }
+
     return GL_NO_ERROR;
 }