glTexCoordPointer(3G)
glTexCoordPointer - define an array of texture coordinates
As shipped in IRIX 6.5. First release of IRIX 6.5.
NAME glTexCoordPointer - define an array of texture coordinates C SPECIFICATION void glTexCoordPointer( GLint size, GLenum type, GLsizei stride, const GLvoid *pointer ) PARAMETERS size Specifies the number of coordinates per array element. Must be 1, 2, 3 or 4. The initial value is 4. type Specifies the data type of each texture coordinate. Symbolic constants GL_SHORT, GL_INT, GL_FLOAT, or GL_DOUBLE are accepted. The initial value is GL_FLOAT. stride Specifies the byte offset between consecutive array elements. If stride is 0, the array elements are understood to be tightly packed. The initial value is 0. pointer Specifies a pointer to the first coordinate of the first element in the array. DESCRIPTION glTexCoordPointer specifies the location and data format of an array of texture coordinates to use when rendering. size specifies the number of coordinates per element, and must be 1, 2, 3, or 4. type specifies the data type of each texture coordinate and stride specifies the byte stride from one array element to the next allowing vertexes and attributes to be packed into a single array or stored in separate arrays. (Single-array storage may be more efficient on some implementations; see glInterleavedArrays.) When a texture coordinate array is specified, size, type, stride, and pointer are saved client-side state. To enable and disable the texture coordinate array, call glEnableClientState and glDisableClientState with the argument GL_TEXTURE_COORD_ARRAY. If enabled, the texture coordinate array is used when glDrawArrays, glDrawElements or glArrayElement is called. Use glDrawArrays to construct a sequence of primitives (all of the same type) from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives by indexing vertexes and vertex attributes and glDrawElements to construct a sequence of primitives by indexing vertexes and vertex attributes. NOTES glTexCoordPointer is available only if the GL version is 1.1 or greater. The texture coordinate array is initially disabled and it won't be accessed when glArrayElement, glDrawElements or glDrawArrays is called. Execution of glTexCoordPointer is not allowed between the execution of glBegin and the corresponding execution of glEnd, but an error may or may not be generated. If no error is generated, the operation is undefined. glTexCoordPointer is typically implemented on the client side with no protocol. The texture coordinate array parameters are client-side state and are therefore not saved or restored by glPushAttrib and glPopAttrib. Use glPushClientAttrib and glPopClientAttrib instead. ERRORS GL_INVALID_VALUE is generated if size is not 1, 2, 3, or 4. GL_INVALID_ENUM is generated if type is not an accepted value. GL_INVALID_VALUE is generated if stride is negative. ASSOCIATED GETS glIsEnabled with argument GL_TEXTURE_COORD_ARRAY glGet with argument GL_TEXTURE_COORD_ARRAY_SIZE glGet with argument GL_TEXTURE_COORD_ARRAY_TYPE glGetPointerv with argument GL_TEXTURE_COORD_ARRAY_POINTER MACHINE DEPENDENCIES On RealityEngine, RealityEngine2, and VTX systems, do not enable or disable GL_VERTEX_ARRAY, GL_VERTEX_ARRAY_EXT, GL_NORMAL_ARRAY, GL_NORMAL_ARRAY_EXT, GL_COLOR_ARRAY, GL_COLOR_ARRAY_EXT, GL_INDEX_ARRAY,GL_INDEX_ARRAY_EXT, GL_TEXTURE_COORD_ARRAY, GL_TEXTURE_COORD_ARRAY_EXT, GL_EDGE_FLAG_ARRAY or GL_EDGE_FLAG_ARRAY_EXT between a call to glNewList and the corresponding call to glEndList. Instead, enable or disable before the call to glNewList. On InfiniteReality systems it is particularly important to minimize the amount of data transferred from the application to the graphics pipe, since the host-to-pipe bandwidth limit can cause a performance bottleneck. One way to reduce the amount of data transferred per vertex is to use properly-aligned byte and short data types whenever possible. Accordingly, the EXT_vertex_array extension on InfiniteReality systems has been optimized for vertex information packed into the following data structures. (Note: v represents vertex coordinates, c represents color components, n represents normal coordinates, and t represents texture coordinates. Normals must have unit length.) struct {GLfloat v[3];} struct {GLubyte c[4]; GLfloat v[3];} struct {GLshort n[3]; GLfloat v[3];} struct {GLubyte c[4]; GLshort n[3]; GLfloat v[3];} struct {GLshort t[2]; GLfloat v[3];} struct {GLshort t[2]; GLubyte c[4]; GLfloat v[3];} struct {GLshort t[2]; GLshort n[3]; GLfloat v[3];} struct {GLshort t[2]; GLubyte c[4]; GLshort n[3]; GLfloat v[3];} struct {GLfloat t[2]; GLfloat v[3];} struct {GLfloat t[2]; GLubyte c[4]; GLfloat v[3];} struct {GLfloat t[2]; GLshort n[3]; GLfloat v[3];} struct {GLfloat t[2]; GLubyte c[4]; GLshort n[3]; GLfloat v[3];} Application-specific fields may be added to these structures, provided that all the fields described above retain their relative order and word alignment. An additional constraint applies when glTexGen is being used. The implementation normally generates all four texture coordinates in parallel, and must take special action to generate just a subset of the four coordinates. Therefore performance is best when none of the texture coordinates are being generated, or when all of them are being generated. For example, when using 2D texturing (generating s and t coordinates) it will be faster to enable texture coordinate generation for the r and q coordinates as well as s and t. Choose a texture generation mode of GL_OBJECT_LINEAR and use the plane equations (0,0,0,0) and (0,0,0,1) for r and q, respectively. Using these structures on InfiniteReality systems can improve performance considerably, compared to structures in which all values are single- precision floating point. SEE ALSO glArrayElement, glColorPointer, glDrawArrays, glDrawElements, glEdgeFlagPointer, glEnable, glGetPointerv, glIndexPointer, glNormalPointer, glPopClientAttrib, glPushClientAttrib, glTexCoord, glVertexPointer