#ifndef MSP_GL_TEXTURE_H_
#define MSP_GL_TEXTURE_H_
-#include <GL/gl.h>
-#include "types.h"
+#include <msp/datafile/objectloader.h>
+#include "gl.h"
+#include "predicate.h"
namespace Msp {
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
+
+ /// 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 TextureFormat
+
+enum TextureWrap
{
- LUMINANCE8,
- LUMINANCE8_ALPHA8,
- RGB8,
- RGBA8,
- BGR8,
- BGRA8
+ /// 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
};
+
+/**
+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
{
-public:
- ~Texture();
+protected:
+ class Loader: public DataFile::ObjectLoader<Texture>
+ {
+ public:
+ Loader(Texture &);
+ private:
+ void filter(TextureFilter);
+ void generate_mipmap(bool);
+ void mag_filter(TextureFilter);
+ void max_anisotropy(float);
+ void min_filter(TextureFilter);
+ void wrap(TextureWrap);
+ void wrap_r(TextureWrap);
+ void wrap_s(TextureWrap);
+ void wrap_t(TextureWrap);
+ };
- void bind() const;
- void parameter(GLenum, int);
- void parameter(GLenum, float);
- void set_min_filter(TextureFilter f) { parameter(GL_TEXTURE_MIN_FILTER, f); }
- void set_mag_filter(TextureFilter f) { parameter(GL_TEXTURE_MAG_FILTER, f); }
- GLenum get_target() const { return target; }
- uint get_id() const { return id; }
+ enum ParameterMask
+ {
+ MIN_FILTER = 1,
+ MAG_FILTER = 2,
+ WRAP_S = 4,
+ WRAP_T = 8,
+ WRAP_R = 16,
+ GENERATE_MIPMAP = 32,
+ COMPARE = 64,
+ COMPARE_FUNC = 128,
+ MAX_ANISOTROPY = 256
+ };
- static void unbind();
-protected:
- uint id;
+ unsigned id;
GLenum target;
+ TextureFilter min_filter;
+ TextureFilter mag_filter;
+ float max_anisotropy;
+ TextureWrap wrap_s;
+ TextureWrap wrap_t;
+ TextureWrap wrap_r;
+ bool gen_mipmap;
+ bool compare;
+ Predicate cmp_func;
+ mutable int dirty_params;
- Texture();
+ Texture(GLenum);
Texture(const Texture &);
Texture &operator=(const Texture &);
- void maybe_bind() const;
+public:
+ ~Texture();
+
+protected:
+ void update_parameter(int) const;
+public:
+ void set_min_filter(TextureFilter);
+ void set_mag_filter(TextureFilter);
+
+ /** Sets filter for both minification and magnification. Since mipmapping
+ is not applicable to magnification, LINEAR is used instead. */
+ void set_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; }
+
+ void bind() const { bind_to(0); }
+ void bind_to(unsigned) const;
+
+ static const Texture *current(unsigned = 0);
+ static void unbind() { unbind_from(0); }
+ static void unbind_from(unsigned);
};
} // namespace GL