From 1bc84de412775abcef84c1f604160121f245b131 Mon Sep 17 00:00:00 2001
From: Thorbjørn Lindeijer <thorbjorn@lindeijer.nl>
Date: Sun, 22 Jul 2012 21:24:31 +0200
Subject: Added support for ARB_texture_non_power_of_two extension

If the graphics driver supports this, there is no need to create
textures with power-of-two dimensions. It is then also preferred to use
regular textures than relying on the older GL_ARB_texture_rectangle
extension.

Reviewed-by: Erik Schilling
---
 src/openglgraphics.cpp  | 5 ++++-
 src/resources/image.cpp | 3 ++-
 src/resources/image.h   | 1 +
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/openglgraphics.cpp b/src/openglgraphics.cpp
index 66d0d0fc..50fee075 100644
--- a/src/openglgraphics.cpp
+++ b/src/openglgraphics.cpp
@@ -113,14 +113,17 @@ bool OpenGLGraphics::setVideoMode(int w, int h, int bpp, bool fs, bool hwaccel)
     char const *glExtensions = (char const *)glGetString(GL_EXTENSIONS);
     GLint texSize;
     bool rectTex = strstr(glExtensions, "GL_ARB_texture_rectangle");
-    if (rectTex)
+    bool npotTex = strstr(glExtensions, "GL_ARB_texture_non_power_of_two");
+    if (rectTex && !npotTex)
     {
         Image::mTextureType = GL_TEXTURE_RECTANGLE_ARB;
+        Image::mPowerOfTwoTextures = false;
         glGetIntegerv(GL_MAX_RECTANGLE_TEXTURE_SIZE_ARB, &texSize);
     }
     else
     {
         Image::mTextureType = GL_TEXTURE_2D;
+        Image::mPowerOfTwoTextures = !npotTex;
         glGetIntegerv(GL_MAX_TEXTURE_SIZE, &texSize);
     }
     Image::mTextureSize = texSize;
diff --git a/src/resources/image.cpp b/src/resources/image.cpp
index 9a3e2ba2..3afa479f 100644
--- a/src/resources/image.cpp
+++ b/src/resources/image.cpp
@@ -36,6 +36,7 @@
 
 #ifdef USE_OPENGL
 bool Image::mUseOpenGL = false;
+bool Image::mPowerOfTwoTextures = true;
 int Image::mTextureType = 0;
 int Image::mTextureSize = 0;
 #endif
@@ -544,7 +545,7 @@ void Image::setLoadAsOpenGL(bool useOpenGL)
 int Image::powerOfTwo(int input)
 {
     int value;
-    if (mTextureType == GL_TEXTURE_2D)
+    if (mPowerOfTwoTextures)
     {
         value = 1;
         while (value < input && value < mTextureSize)
diff --git a/src/resources/image.h b/src/resources/image.h
index 7df74c3f..33db7848 100644
--- a/src/resources/image.h
+++ b/src/resources/image.h
@@ -249,6 +249,7 @@ class Image : public Resource
         int mTexWidth, mTexHeight;
 
         static bool mUseOpenGL;
+        static bool mPowerOfTwoTextures;
         static int mTextureType;
         static int mTextureSize;
 #endif
-- 
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