HP Workstation zx2000 OpenGL 1.1 Reference for HP-UX 11.x - Page 119

D glDrawElements glDrawElements glDrawElements: render primitives from array data. C Specification void glDrawElements( GLenum mode, GLsizei count, GLenum type, const GLvoid *indices) Parameters mode count type indices Specifies what kind of primitives to render. Symbolic constants GL_POINTS, GL_LINE_STRIP, GL_LINE_LOOP, GL_LINES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_TRIANGLES, GL_QUAD_STRIP, GL_QUADS, and GL_POLYGON are accepted. Specifies the number of elements to be rendered. Specifies the type of the values in indices. Must be one of GL_UNSIGNED_BYTE, GL_UNSIGNED_SHORT, or GL_UNSIGNED_INT. Specifies a pointer to the location where the indices are stored. Description glDrawElements specifies multiple geometric primitives with very few subroutine calls. Instead of calling a GL function to pass each individual vertex, normal, texture coordinate, edge flag, or color, you can pre-specify separate arrays of vertexes, normals, and so on and use them to construct a sequence of primitives with a single call to glDrawElements. When glDrawElements is called, it uses count sequential elements from an enabled array, starting at indices to construct a sequence of geometric primitives. mode specifies what kind of primitives are constructed, and how the array elements construct these primitives. If more than one array is enabled, each is used. If GL_VERTEX_ARRAY is not enabled, no geometric primitives are constructed. Vertex attributes that are modified by glDrawElements have an unspecified value after glDrawElements returns. For example, if GL_COLOR_ARRAY is enabled, the value of the current color is undefined after glDrawElements executes. Attributes that aren't modified remain well defined. Notes glDrawElements is available only if the GL version is 1.1 or greater. Chapter 4 119