glDrawArraysEXT(3G) OpenGL Reference glDrawArraysEXT(3G)NAME
glDrawArraysEXT - render primitives from array data
C SPECIFICATION
void glDrawArraysEXT( GLenum mode,
GLint first,
GLsizei count )
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.
first Specifies the starting index in the enabled arrays.
count Specifies the number of indices which should be rendered.
DESCRIPTION
glDrawArraysEXT makes it possible to specify multiple geometric
primitives with very few subroutine calls. Instead of calling an OpenGL
procedure to pass each individual vertex, normal, or color, separate
arrays of vertices, normals, and colors can be prespecified, and used to
define a sequence of primitives (all of the same type) with a single call
to glDrawArraysEXT.
When glDrawArraysEXT is called, count sequential elements from each
enabled array are used to construct a sequence of geometric primitives,
beginning with element first. mode specifies what kind of primitives are
constructed, and how the array elements are used to construct these
primitives. If GL_VERTEX_ARRAY_EXT is not enabled, no geometric
primitives are generated.
Vertex attributes that are modified by glDrawArraysEXT have an
unspecified value after glDrawArraysEXT returns. For example, if
GL_COLOR_ARRAY_EXT is enabled, the value of the current color is
undefined after glDrawArraysEXT executes. Attributes that aren't
modified remain well defined.
Operation of glDrawArraysEXT is atomic with respect to error generation.
If an error is generated, no other operations take place.
NOTES
glDrawArraysEXT may be included in display lists. If glDrawArraysEXT 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.
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glDrawArraysEXT(3G) OpenGL Reference glDrawArraysEXT(3G)
Static array data may be read and cached by the implementation at any
time. If static array elements are modified and the arrays are not
respecified, the results of any subsequent calls to glDrawArraysEXT are
undefined.
Although it is not an error to respecify an array between the execution
of glBegin and the corresponding execution of glEnd, the result of such
respecification is undefined.
glDrawArraysEXT is part of the EXT_vertex_array extension, not part of
the core GL command set. If GL_EXT_vertex_array is included in the string
returned by glGetString, when called with argument GL_EXTENSIONS,
extension EXT_vertex_array is supported.
ERRORS
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 glDrawArraysEXT is called between
the execution of glBegin and the corresponding execution of glEnd.
SEE ALSO
glArrayElementEXT, glColorPointerEXT, glEdgeFlagPointerEXT,
glGetPointervEXT, glIndexPointerEXT, glNormalPointerEXT,
glTexCoordPointerEXT, glVertexPointerEXT
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