From 172c60a9000533cb9f310e28f1d602b66878ad4d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20Vondru=C5=A1?= <mosra@centrum.cz>
Date: Tue, 8 May 2012 01:20:02 +0200
Subject: [PATCH] Support for anisotropic filtering.

---
 src/AbstractTexture.cpp |  6 ++++++
 src/AbstractTexture.h   | 23 ++++++++++++++++++++++-
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/AbstractTexture.cpp b/src/AbstractTexture.cpp
index 95f9c087f..3135dd4ac 100644
--- a/src/AbstractTexture.cpp
+++ b/src/AbstractTexture.cpp
@@ -46,6 +46,12 @@ static_assert((filter_or(NearestNeighbor, BaseLevel) == GL_NEAREST) &&
 #undef filter_or
 #endif
 
+GLfloat AbstractTexture::maxSupportedAnisotropy() {
+    GLfloat value;
+    glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &value);
+    return value;
+}
+
 void AbstractTexture::setMinificationFilter(Filter filter, Mipmap mipmap) {
     CORRADE_ASSERT(_target != GL_TEXTURE_RECTANGLE || mipmap == Mipmap::BaseLevel, "AbstractTexture: rectangle textures cannot have mipmaps", )
 
diff --git a/src/AbstractTexture.h b/src/AbstractTexture.h
index d0ae91bad..9569b8388 100644
--- a/src/AbstractTexture.h
+++ b/src/AbstractTexture.h
@@ -29,7 +29,6 @@ namespace Magnum {
 See Texture, CubeMapTexture and CubeMapTextureArray documentation for more
 information.
 @todo Add glPixelStore encapsulation
-@todo Anisotropic filtering
 */
 class MAGNUM_EXPORT AbstractTexture {
     AbstractTexture(const AbstractTexture& other) = delete;
@@ -419,6 +418,14 @@ class MAGNUM_EXPORT AbstractTexture {
 
         /*@}*/
 
+        /**
+         * @brief Max supported anisotropy
+         *
+         * @see setMaxAnisotropy()
+         * @requires_extension <tt>EXT_texture_filter_anisotropic</tt>
+         */
+        static GLfloat maxSupportedAnisotropy();
+
         /**
          * @brief Constructor
          * @param layer     %Texture layer (number between 0 and 31)
@@ -498,6 +505,20 @@ class MAGNUM_EXPORT AbstractTexture {
             glTexParameterfv(_target, GL_TEXTURE_BORDER_COLOR, color.data());
         }
 
+        /**
+         * @brief Set max anisotropy
+         *
+         * Default value is `1.0`, which means no anisotropy. Set to value
+         * greater than `1.0` for anisotropic filtering.
+         *
+         * @see maxSupportedAnisotropy()
+         * @requires_extension <tt>EXT_texture_filter_anisotropic</tt>
+         */
+        inline void setMaxAnisotropy(GLfloat anisotropy) {
+            bind();
+            glTexParameterf(_target, GL_TEXTURE_MAX_ANISOTROPY_EXT, anisotropy);
+        }
+
         /**
          * @brief Generate mipmap
          *