Manpages OpenGL - glmultidrawelements

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Name

glMultiDrawElements — render multiple sets of primitives by specifying indices of array data elements

C Specification

`void glMultiDrawElements(`	GLenum	`mode`,
	const GLsizei *	`count`,
	GLenum	`type`,
	const GLvoid **	`indices`,
	GLsizei	`primcount)`;

Parameters

mode: 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.
count: Points to an array of the elements counts.
type: Specifies the type of the values in indices. Must be one of GL_UNSIGNED_BYTE, GL_UNSIGNED_SHORT, or GL_UNSIGNED_INT.
indices: Specifies a pointer to the location where the indices are stored.
primcount: Specifies the size of the count array.

Description

glMultiDrawElements specifies multiple sets of 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 prespecify separate arrays of vertices, normals, and so on, and use them to construct a sequence of primitives with a single call to glMultiDrawElements.

glMultiDrawElements is identical in operation to glDrawElements except that primcount separate lists of elements are specified.

Vertex attributes that are modified by glMultiDrawElements have an unspecified value after glMultiDrawElements returns. For example, if GL_COLOR_ARRAY is enabled, the value of the current color is undefined after glMultiDrawElements executes. Attributes that aren't modified maintain their previous values.

Notes

glMultiDrawElements is available only if the GL version is 1.4 or greater.

glMultiDrawElements is included in display lists. If glMultiDrawElements is entered into a display list, the necessary array data (determined by the array pointers and enables) is also entered into the display list. Because the array pointers and enables are client-side state, their values affect display lists when the lists are created, not when the lists are executed.

Errors

GL_INVALID_ENUM is generated if mode is not an accepted value.

GL_INVALID_VALUE is generated if primcount is negative.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to an enabled array or the element array and the buffer object's data store is currently mapped.

GL_INVALID_OPERATION is generated if glMultiDrawElements is executed between the execution of glBegin and the corresponding glEnd.