From cbab0e0682db2bcf5655f64d5b7ef83daed07f6e Mon Sep 17 00:00:00 2001
From: Oleg Romashin <romaxa@gmail.com>
Date: Sat, 28 Apr 2012 09:05:41 -0400
Subject: [PATCH] Bug 743314 - Force CanUploadSubtextures on Maemo6 harmattan.
 r=chrislord.net

---
 gfx/gl/GLContext.cpp            | 5 +++++
 gfx/gl/GLContext.h              | 1 +
 gfx/gl/GLContextProviderEGL.cpp | 4 ++++
 3 files changed, 10 insertions(+)

diff --git a/gfx/gl/GLContext.cpp b/gfx/gl/GLContext.cpp
index d23c9eb65045..79b6d756964c 100644
--- a/gfx/gl/GLContext.cpp
+++ b/gfx/gl/GLContext.cpp
@@ -641,6 +641,11 @@ GLContext::CanUploadSubTextures()
     if (!mWorkAroundDriverBugs)
         return true;
 
+    // Lock surface feature allows to mmap texture memory and modify it directly
+    // this feature allow us modify texture partially without full upload
+    if (HasLockSurface())
+        return true;
+
     // There are certain GPUs that we don't want to use glTexSubImage2D on
     // because that function can be very slow and/or buggy
     if (Renderer() == RendererAdreno200 || Renderer() == RendererAdreno205)
diff --git a/gfx/gl/GLContext.h b/gfx/gl/GLContext.h
index 497e2e4852b2..c93888963c9c 100644
--- a/gfx/gl/GLContext.h
+++ b/gfx/gl/GLContext.h
@@ -731,6 +731,7 @@ public:
     bool CanUploadSubTextures();
     bool CanUploadNonPowerOfTwo();
     bool WantsSmallTiles();
+    virtual bool HasLockSurface() { return false; }
 
     /**
      * If this context wraps a double-buffered target, swap the back
diff --git a/gfx/gl/GLContextProviderEGL.cpp b/gfx/gl/GLContextProviderEGL.cpp
index 72301873692e..dc567dfb5da2 100644
--- a/gfx/gl/GLContextProviderEGL.cpp
+++ b/gfx/gl/GLContextProviderEGL.cpp
@@ -597,6 +597,10 @@ public:
         return h;
     }
 
+    virtual bool HasLockSurface() {
+        return sEGLLibrary.HasKHRLockSurface();
+    }
+
 protected:
     friend class GLContextProviderEGL;