#include "datatype.h"
#include "pixelformat.h"
#include "texture.h"
+#include "vector.h"
namespace Msp {
namespace GL {
/**
Cube map texture, consisting of six square faces. All of the faces must be of
the same size. A cube map texture is addressed by three-dimensional texture
-coordinates. The face is first selected according to the largest coordinate,
-and the remaining two coordinates are used to sample the face image.
+coordinates, with a principal range of [-1, 1]. The face is first selected
+according to the largest coordinate, and the remaining two coordinates are used
+to sample the face image. The images are oriented so that the cross product of
+the s and t axes will point into the cube.
All faces of a cube map texture must be allocated for it to be usable.
unsigned size;
unsigned allocated;
+ static Vector3 directions[6];
+
public:
TextureCube();
unsigned get_size() const { return size; }
private:
unsigned get_level_size(unsigned);
+
+public:
+ /** Translates indices into face constants. Valid indices are between 0
+ and 5, inclusive. */
+ static TextureCubeFace enumerate_faces(unsigned);
+
+ /** Returns a vector pointing out of the face. */
+ static const Vector3 &get_face_direction(TextureCubeFace);
+
+ /** Returns a vector in the direction of the s axis of the face. */
+ static const Vector3 &get_s_direction(TextureCubeFace);
+
+ /** Returns a vector in the direction of the t axis of the face. */
+ static const Vector3 &get_t_direction(TextureCubeFace);
+
+ /** Returns a vector pointing to the center a texel. */
+ Vector3 get_texel_direction(TextureCubeFace, unsigned, unsigned);
};
} // namespace GL