Committing patch #25676 Anisotropic filtering in viewport and BGE by me.

This patch adds anisotropic filtering of textures in the viewport and the BGE. The quality of the filtering is adjustable in the user preferences under System. For more information on anisotropic filtering:
http://en.wikipedia.org/wiki/Anisotropic_filtering

One current limitation of this setup (having the option a user preference) is it makes runtimes more troublesome. Runtimes don't have user preferences set, so for now the blender player defaults to 2x AF. Options will be added later to change this value (probably a command line option).

1 files changed, 24 insertions, 1 deletions

diff --git a/source/blender/gpu/intern/gpu_draw.c b/source/blender/gpu/intern/gpu_draw.c
index 7dfbc52819e..87d25ac850a 100644
--- a/source/blender/gpu/intern/gpu_draw.c
+++ b/source/blender/gpu/intern/gpu_draw.c
@@ -246,8 +246,9 @@ static struct GPUTextureState {
 	int domipmap, linearmipmap;
 
 	int alphamode;
+	float anisotropic;
 	MTFace *lasttface;
-} GTS = {0, 0, 0, 0, 0, 0, 0, 0, NULL, NULL, 1, 0, -1, NULL};
+} GTS = {0, 0, 0, 0, 0, 0, 0, 0, NULL, NULL, 1, 0, -1, 1.f, NULL};
 
 /* Mipmap settings */
 
@@ -292,6 +293,26 @@ static GLenum gpu_get_mipmap_filter(int mag)
 	}
 }
 
+/* Anisotropic filtering settings */
+void GPU_set_anisotropic(float value)
+{
+	if (GTS.anisotropic != value)
+	{
+		GPU_free_images();
+
+		/* Clamp value to the maximum value the graphics card supports */
+		if (value > GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT)
+			value = GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT;
+
+		GTS.anisotropic = value;
+	}
+}
+
+float GPU_get_anisotropic()
+{
+	return GTS.anisotropic;
+}
+
 /* Set OpenGL state for an MTFace */
 
 static void gpu_make_repbind(Image *ima)
@@ -559,6 +580,8 @@ int GPU_verify_image(Image *ima, ImageUser *iuser, int tftile, int compare, int
 		ima->tpageflag |= IMA_MIPMAP_COMPLETE;
 	}
 
+	if (GLEW_EXT_texture_filter_anisotropic)
+		glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, GPU_get_anisotropic());
 	/* set to modulate with vertex color */
 	glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);