texture 3 LIBG3D Library texture Texture loading and manipulation #include <g3d/texture.h> #define G3D_FLAG_IMG_GREYSCALE enum G3DTexEnv; G3DImage; G3DImage* g3d_texture_load_cached (G3DContext *context, G3DModel *model, const gchar *filename); G3DImage* g3d_texture_load_from_stream (G3DContext *context, G3DModel *model, G3DStream *stream); G3DImage* g3d_texture_load (G3DContext *context, const gchar *filename); void g3d_texture_free (G3DImage *texture); gboolean g3d_texture_prepare (G3DImage *texture); gboolean g3d_texture_flip_y (G3DImage *texture); G3DImage* g3d_texture_merge_alpha (G3DImage *image, G3DImage *aimage); A texture is an image used in materials. Here are some helper functions, mostly for cached loading of a G3DImage. G3D_FLAG_IMG_GREYSCALE#define G3D_FLAG_IMG_GREYSCALE (1L << 1) The image just uses the red channel for grey value G3DTexEnvtypedef enum { G3D_TEXENV_UNSPECIFIED = 0, G3D_TEXENV_BLEND, G3D_TEXENV_DECAL, G3D_TEXENV_MODULATE, G3D_TEXENV_REPLACE } G3DTexEnv; Specify how the texture should interact with other material properties. G3D_TEXENV_UNSPECIFIED unspecified, application decides G3D_TEXENV_BLEND use blending G3D_TEXENV_DECAL use as decal G3D_TEXENV_MODULATE use modulate G3D_TEXENV_REPLACE replace color G3DImagetypedef struct { gchar *name; guint32 width; guint32 height; guint8 depth; guint32 flags; guint8 *pixeldata; guint32 tex_id; G3DTexEnv tex_env; G3DFloat tex_scale_u; G3DFloat tex_scale_v; } G3DImage; Object containing a two-dimensional pixel image. gchar *name; name of image guint32 width; width of image in pixels guint32 height; height of image in pixels guint8 depth; depth of image in bits guint32 flags; flags guint8 *pixeldata; the binary image data guint32 tex_id; the OpenGL texture id, should be unique model-wide G3DTexEnv tex_env; texture environment flags G3DFloat tex_scale_u; factor scaling texture width, should be 1.0 for most cases G3DFloat tex_scale_v; factor scaling texture height, should be 1.0 for most cases g3d_texture_load_cachedG3DImage* g3d_texture_load_cached (G3DContext *context, G3DModel *model, const gchar *filename); Loads a texture image from file and attaches it to a hash table in the model. On a second try to load this texture it is returned from cache. context : a valid context model : a valid model filename : the file name of the texture to load Returns : the texture image g3d_texture_load_from_streamG3DImage* g3d_texture_load_from_stream (G3DContext *context, G3DModel *model, G3DStream *stream); Load a texture image from a stream. The file type is determined by the extension of the stream URI, so it should be valid. If model is not NULL the texture image is cached (or retrieved from cache if available). context : a valid context model : a valid model or NULL stream : an open stream Returns : the texture image or NULL in case of an error. g3d_texture_loadG3DImage* g3d_texture_load (G3DContext *context, const gchar *filename); Load a texture from a file. The type of file is determined by the file extension. context : a valid context filename : the file name of the texture Returns : the texture image or NULL in case of an error. g3d_texture_freevoid g3d_texture_free (G3DImage *texture); Frees all memory used by this texture image. texture : a texture image g3d_texture_preparegboolean g3d_texture_prepare (G3DImage *texture); Resizes the image to dimensions which are a power of 2 to be usable as an OpenGL texture. (FIXME: unimplemented) texture : a texture image Returns : TRUE on success, FALSE else g3d_texture_flip_ygboolean g3d_texture_flip_y (G3DImage *texture); Mirror the image along the x axis - all y coordinates are inverted. texture : a texture image Returns : TRUE on success, FALSE on error. g3d_texture_merge_alphaG3DImage* g3d_texture_merge_alpha (G3DImage *image, G3DImage *aimage); Merges alpha information from aimage into output image. If image is NULL a new image is created, else image is returned with alpha from aimage. image : a texture image or NULL aimage : an image with alpha information Returns : a texture image or NULL in case of an error.