- void storage(PixelFormat, sizei, sizei, sizei, int);
- void image(int, PixelFormat, GLenum, const void *);
- void sub_image(int, int, int, sizei, sizei, sizei, PixelFormat, GLenum, const void *);
- void load_image(const std::string &fn, int dp=-1);
- sizei get_width() const { return width; }
- sizei get_height() const { return height; }
- sizei get_depth() const { return depth; }
+
+ /** Defines storage structure for the texture. Must be called before an
+ image can be uploaded. Once storage is defined, it can't be changed. */
+ void storage(PixelFormat fmt, unsigned wd, unsigned ht, unsigned dp);
+
+ /** Allocates storage for the texture. The contents are initially
+ undefined. If storage has already been allocated, does nothing. */
+ void allocate(unsigned level);
+
+ /** Uploads an image to the texture. Storage must be defined beforehand.
+ The image data must have dimensions and format compatible with the defined
+ storage. */
+ void image(unsigned level, PixelFormat fmt, DataType type, const void *data);
+
+ /** Updates a cuboid-shaped region of the texture. Storage must be defined
+ and allocated beforehand. The update region must be fully inside the
+ texture. */
+ void sub_image(unsigned level,
+ int x, int y, int z, unsigned wd, unsigned ht, unsigned dp,
+ PixelFormat fmt, DataType type, const void *data);
+
+ /** Loads an image from a file and uploads it to the texture. If storage
+ has not been defined, it will be set to match the loaded image. To
+ construct a three-dimensional texture from a two-dimensional image, the
+ image is interpreted as an array of consecutive images. If dp is -1, the
+ texture's width and height are equal. If dp is -2, the texture's height and
+ depth are equal. Otherwise, dp must be positive and determines the
+ texture's depth. In all cases, the image's height must equal the texture's
+ height times its depth. */
+ void load_image(const std::string &fn, int dp = -1);
+
+ unsigned get_width() const { return width; }
+ unsigned get_height() const { return height; }
+ unsigned get_depth() const { return depth; }
+private:
+ void get_level_size(unsigned, unsigned &, unsigned &, unsigned &);