@node Textures
@section Textures

Textures are images loaded in graphics memory. Sly supports many
texture formats via the FreeImage library. A texture object can
describe a full image or a rectangular section of an image.

@anchor{2d texture make-texture}@defun make-texture id parent width height s1 t1 s2 t2
Create a new texture object.  ID is the OpenGL texture id.  PARENT is a
texture object (if this texture only represents a region of another
texture) or #f.  WIDTH and HEIGHT are the texture dimensions in pixels.
S1, T1, S2, and T2 are the OpenGL texture coordinates representing the
area of the texture that will be rendered.

@end defun

@anchor{2d texture make-texture-region}@defun make-texture-region texture x y width height
Creates new texture region object.  TEXTURE is the region's parent
texture.  X, Y, WIDTH, and HEIGHT represent the region of the texture
that will be rendered, in pixels.

@end defun

@anchor{2d texture load-texture}@defun load-texture filename
Load a texture from an image file at FILENAME.

@end defun

@anchor{2d texture texture?}@defspec texture?
@end defspec

@anchor{2d texture texture-region?}@defun texture-region? texture
Return #t if TEXTURE has a parent texture.

@end defun

@anchor{2d texture texture-id}@defspec texture-id
@end defspec

@anchor{2d texture texture-width}@defspec texture-width
@end defspec

@anchor{2d texture texture-height}@defspec texture-height
@end defspec

@anchor{2d texture texture-s1}@defspec texture-s1
@end defspec

@anchor{2d texture texture-t1}@defspec texture-t1
@end defspec

@anchor{2d texture texture-s2}@defspec texture-s2
@end defspec

@anchor{2d texture texture-t2}@defspec texture-t2
@end defspec

@anchor{2d texture surface->texture}@defvar surface->texture
[unbound!]
@end defvar

@anchor{2d texture draw-texture}@defun draw-texture texture x y [color]
Render a textured quad in GL immediate mode.

@end defun