GLDRAWARRAYS() MachTen Programmer’s Manual GLDRAWARRAYS()

NAME
glDrawArrays - render primitives from array data

C SPECIFICATION
void glDrawArrays( GLenum mode,
GLint first,
GLsizei count )

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PARAMETERS
mode Specifies what kind of primitives to render. Sym-
bolic 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 to be rendered.

DESCRIPTION
glDrawArrays specifies multiple geometric primitives with
very few subroutine calls. Instead of calling a GL proce-
dure to pass each individual vertex, normal, texture coor-
dinate, edge flag, or color, you can prespecify separate
arrays of vertexes, normals, and colors and use them to
construct a sequence of primitives with a single call to
glDrawArrays.

When glDrawArrays is called, it uses count sequential ele-
ments from each enabled array to construct a sequence of
geometric primitives, beginning with element first. mode
specifies what kind of primitives are constructed, and how
the array elements construct those primitives. If
GL_VERTEX_ARRAY is not enabled, no geometric primitives
are generated.

Vertex attributes that are modified by glDrawArrays have
an unspecified value after glDrawArrays returns. For exam-
ple, if GL_COLOR_ARRAY is enabled, the value of the cur-
rent color is undefined after glDrawArrays executes.
Attributes that aren’t modified remain well defined.

NOTES
glDrawArrays is available only if the GL version is 1.1 or
greater.

glDrawArrays is included in display lists. If glDrawArrays
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 count is negative.

GL_INVALID_OPERATION is generated if glDrawArrays is exe-
cuted between the execution of glBegin and the correspond-
ing glEnd.

SEE ALSO
glArrayElement, glColorPointer, glDrawElements, glEdge-
FlagPointer,
glGetPointerv, glIndexPointer, glInterleavedArrays, glNor-
malPointer,
glTexCoordPointer, glVertexPointer

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