glDrawElements — render primitives from array data
void glDrawElements(
|
GLenum mode, |
GLsizei count, | |
GLenum type, | |
const void * indices) ; |
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 byte offset (cast to a pointer type) into the buffer bound to GL_ELEMENT_ARRAY_BUFFER
to start reading indices from. If no buffer is bound, specifies a pointer to the location where the indices are stored.
glDrawElements
specifies multiple geometric primitives
with very few subroutine calls. It is possible to prespecify
separate arrays of attributes 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.
To enable and disable a generic vertex attribute array, call glEnableVertexAttribArray and glDisableVertexAttribArray.
If an array corresponding to a generic attribute required by a vertex shader is not enabled, then the corresponding element is taken from the current generic attribute state.
GL_INVALID_ENUM
is generated if mode
is not an accepted value.
GL_INVALID_VALUE
is generated if count
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_FRAMEBUFFER_OPERATION
is generated if the currently bound framebuffer is not
framebuffer complete (i.e. the return value from
glCheckFramebufferStatus is not GL_FRAMEBUFFER_COMPLETE
).
GL_INVALID_OPERATION
is generated if transform feedback is active and not paused.
OpenGL ES API Version | ||
---|---|---|
Function Name | 2.0 | 3.0 |
glDrawElements | ✔ | ✔ |
glCheckFramebufferStatus, glDisableVertexAttribArray, glDrawArrays, glDrawArraysInstanced, glDrawElementsInstanced, glDrawRangeElements, glEnableVertexAttribArray
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