Minor fixes, courtesy of Apple's compiler

[libs/gl.git] / source / texture.h

diff --git a/source/texture.h b/source/texture.h
index 6d26f23684200405018cfd1f56c3286c32d75227..af0844c55e26938f00b2201e2f10abd576ece537 100644 (file)
--- a/source/texture.h
+++ b/source/texture.h
@@ -1,14 +1,6 @@
-/* $Id$
-
-This file is part of libmspgl
-Copyright © 2007  Mikko Rasa, Mikkosoft Productions
-Distributed under the LGPL
-*/
-
 #ifndef MSP_GL_TEXTURE_H_
 #define MSP_GL_TEXTURE_H_
 
-#include <istream>
 #include <msp/datafile/objectloader.h>
 #include "gl.h"
 #include "predicate.h"
@@ -18,21 +10,35 @@ namespace GL {
 
 enum TextureFilter
 {
-       NEAREST                = GL_NEAREST,
-       LINEAR                 = GL_LINEAR,
+       /// No filtering
+       NEAREST = GL_NEAREST,
+
+       /// Bilinear filtering
+       LINEAR = GL_LINEAR,
+
+       /// Mipmapping without filtering
        NEAREST_MIPMAP_NEAREST = GL_NEAREST_MIPMAP_NEAREST,
-       NEAREST_MIPMAP_LINEAR  = GL_NEAREST_MIPMAP_LINEAR,
-       LINEAR_MIPMAP_NEAREST  = GL_LINEAR_MIPMAP_NEAREST,
-       LINEAR_MIPMAP_LINEAR   = GL_LINEAR_MIPMAP_LINEAR
-};
 
-std::istream &operator>>(std::istream &, TextureFilter &);
+       /// Linear filtering between two mipmap levels
+       NEAREST_MIPMAP_LINEAR = GL_NEAREST_MIPMAP_LINEAR,
+
+       /// Bilinear filtering on the closest mipmap level
+       LINEAR_MIPMAP_NEAREST = GL_LINEAR_MIPMAP_NEAREST,
+
+       /// Trilinear filtering between two mipmap levels
+       LINEAR_MIPMAP_LINEAR = GL_LINEAR_MIPMAP_LINEAR
+};
 
 
 enum TextureWrap
 {
-       REPEAT          = GL_REPEAT,
-       CLAMP_TO_EDGE   = GL_CLAMP_TO_EDGE,
+       /// Tile the texture infinitely
+       REPEAT = GL_REPEAT,
+
+       /// Extend the texels at the edge of the texture to infinity
+       CLAMP_TO_EDGE = GL_CLAMP_TO_EDGE,
+
+       /// Tile the texture, with every other repetition mirrored
        MIRRORED_REPEAT = GL_MIRRORED_REPEAT
 };
 
@@ -41,6 +47,21 @@ enum TextureWrap
 Base class for textures.  This class only defines operations common for all
 texture types and is not instantiable.  For specifying images for textures, see
 one of the dimensioned texture classes.
+
+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.
+
+When a mipmapped filter is in use, the texture consists of a stack of mipmap
+images.  Level 0 is the base image.  Each level above 0 has half the size of
+the previous level, rounded down and clamped to 1.  The level with size 1 in
+all dimensions is the last mipmap level.  All levels must be allocated for the
+texture to be usable.
+
+If texture coordinates fall outside of the principal range of the texture,
+wrapping is applied.  The default for all directions is REPEAT.
 */
 class Texture
 {
@@ -49,8 +70,10 @@ protected:
        {
        public:
                Loader(Texture &);
+       private:
                void generate_mipmap(bool);
                void mag_filter(TextureFilter);
+               void max_anisotropy(float);
                void min_filter(TextureFilter);
                void wrap(TextureWrap);
                void wrap_r(TextureWrap);
@@ -67,13 +90,15 @@ protected:
                WRAP_R = 16,
                GENERATE_MIPMAP = 32,
                COMPARE = 64,
-               COMPARE_FUNC = 128
+               COMPARE_FUNC = 128,
+               MAX_ANISOTROPY = 256
        };
 
        unsigned id;
        GLenum target;
        TextureFilter min_filter;
        TextureFilter mag_filter;
+       float max_anisotropy;
        TextureWrap wrap_s;
        TextureWrap wrap_t;
        TextureWrap wrap_r;
@@ -93,13 +118,28 @@ protected:
 public:
        void set_min_filter(TextureFilter);
        void set_mag_filter(TextureFilter);
+       void set_max_anisotropy(float);
+
+       /** Sets the wrapping mode for all coordinates. */
        void set_wrap(TextureWrap);
+
        void set_wrap_s(TextureWrap);
        void set_wrap_t(TextureWrap);
        void set_wrap_r(TextureWrap);
+
+       /** Sets automatic mipmap generation.  If enabled, mipmaps are generated
+       when a texture image is uploaded. */
        void set_generate_mipmap(bool);
+
+       /** Sets depth texture comparison.  Has no effect on other formats.  When
+       comparison is enabled, the third component of the texture coordinate is
+       compared against the texel value, and the result is returned as the texture
+       sample. */
        void set_compare_enabled(bool);
+
+       /** Sets the function to use for depth comparison. */
        void set_compare_func(Predicate);
+
        GLenum get_target() const { return target; }
        unsigned get_id() const { return id; }