Manpages OpenGL - gldrawelementsinstancedbasevertex

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Name

glDrawElementsInstancedBaseVertex — render multiple instances of a set of primitives from array data with a per-element offset

C Specification

`void glDrawElementsInstancedBaseVertex(`	GLenum	`mode`,
	GLsizei	`count`,
	GLenum	`type`,
	GLvoid *	`indices`,
	GLsizei	`primcount`,
	GLint	`basevertex)`;

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, and GL_TRIANGLES are accepted.
count: Specifies the number of elements to be rendered.
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 number of instances of the indexed geometry that should be drawn.
basevertex: Specifies a constant that should be added to each element of indices when chosing elements from the enabled vertex arrays.

Description

glDrawElementsInstancedBaseVertex behaves identically to glDrawElementsInstanced except that the ith element transferred by the corresponding draw call will be taken from element indices[i] + basevertex of each enabled array. If the resulting value is larger than the maximum value representable by type, it is as if the calculation were upconverted to 32-bit unsigned integers (with wrapping on overflow conditions). The operation is undefined if the sum would be negative.

Notes

glDrawElementsInstancedBaseVertex is only supported if the GL version is 3.2 or greater.

Errors

GL_INVALID_ENUM is generated if mode is not an accepted value.

GL_INVALID_VALUE is generated if count or primcount is negative.

GL_INVALID_OPERATION is generated if a geometry shader is active and mode is incompatible with the input primitive type of the geometry shader in the currently installed program object.

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.