X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Fcore%2Fsampler.h;fp=source%2Fcore%2Fsampler.h;h=7cf3d83a7b0915481eef1417e2fe48c0a1e8bcee;hb=190a7e11237351f6b730c28f7b16f183e8adc69c;hp=c79068775b144499943196b316dc0f8f0406f75b;hpb=be6ffe96ecb4707599fe1a6f620c348760213d46;p=libs%2Fgl.git

diff --git a/source/core/sampler.h b/source/core/sampler.h
index c7906877..7cf3d83a 100644
--- a/source/core/sampler.h
+++ b/source/core/sampler.h
@@ -48,18 +48,12 @@ enum TextureWrap
 
 
 /**
-Samplers are used to access texture data in shaders.  To use a sampler with a
-texture, bind it to the same texture unit.  Each texture has a default sampler
-which is used if no external sampler is bound.
-
-A texture is generally rendered at a size that's either smaller or larger than
-its native size, so that the texture coordinates do not exactly correspond to
-the texels of the texture.  The kind of filtering used, if any, is determined
-by the minification and magnification filter parameters.  The default is LINEAR
-for magnification and NEAREST_MIPMAP_LINEAR for minification.
-
-If texture coordinates fall outside of the principal range of the texture,
-wrapping is applied.  The default for all directions is REPEAT.
+Stores settings affecting how values are obtained from textures in a shader.
+Samplers are always used together with textures.
+
+Texture coordinates are first transformed according to the wrap mode for each
+axis.  One or more texel values are then read and combined according to the
+filtering mode.
 */
 class Sampler: public SamplerBackend
 {
@@ -112,7 +106,12 @@ private:
 	void update() const;
 
 public:
+	/** Sets filter to use when the texture is drawn at a size smaller than
+	original. */
 	void set_min_filter(TextureFilter);
+
+	/** Sets filter to use when the texture is drawn at a size larger than
+	original.  Mipmapped filters can't be used. */
 	void set_mag_filter(TextureFilter);
 
 	/** Sets filter for both minification and magnification.  If a mipmapping
@@ -122,6 +121,9 @@ public:
 	TextureFilter get_min_filter() const { return min_filter; }
 	TextureFilter get_mag_filter() const { return mag_filter; }
 
+	/** Sets the maximum aspect ratio for anisotropic filtering.  If greater
+	than 1, filtering will consider more than than four samples when the texture
+	is drawn at an oblique angle. */
 	void set_max_anisotropy(float);
 	float get_max_anisotropy() const { return max_anisotropy; }
 
@@ -132,7 +134,9 @@ public:
 	void set_wrap_t(TextureWrap);
 	void set_wrap_r(TextureWrap);
 
+	/** Sets the border color for CLAMP_TO_BORDER wrap mode. */
 	void set_border_color(const Color &);
+
 	const Color &get_border_color() const { return border_color; }
 
 	/** Disables depth comparison. */
@@ -140,7 +144,7 @@ public:
 
 	/** Enables depth comparison and sets the compare function.  Only has an
 	effect when used with a depth texture.  When depth comparison is enabled,
-	the third component of the texture coordinate is compared against the texel
+	the last component of the texture coordinate is compared against the texel
 	value, and the result is returned as the texture sample.*/
 	void set_compare(Predicate);