/**
-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
{
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
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; }
- /** Sets the wrapping mode for all coordinates. */
- void set_wrap(TextureWrap);
+ float get_max_anisotropy() const { return max_anisotropy; }
void set_wrap_s(TextureWrap);
void set_wrap_t(TextureWrap);
void set_wrap_r(TextureWrap);
+ /** Sets the wrapping mode for all coordinates. */
+ void set_wrap(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. */
/** 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);