gl.DrawArrays(mode, first, count)
gl.DrawArrays()
specifies multiple geometric primitives with very few subroutine calls. Instead of calling a GL
procedure to pass each individual vertex, normal, texture coordinate, edge flag, or color, you can prespecify
separate arrays of vertices, normals, and colors and use them to construct a sequence of primitives with a
single call to gl.DrawArrays()
.
When gl.DrawArrays()
is called, it uses count
sequential elements 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. mode
can be set to the 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
, or #GL_POLYGON
.
Vertex attributes that are modified by gl.DrawArrays()
have an unspecified value after gl.DrawArrays()
returns.
For example, if #GL_COLOR_ARRAY
is enabled, the value of the current color is undefined after gl.DrawArrays()
executes. Attributes that aren't modified remain well defined.
gl.DrawArrays()
is included in display lists. If gl.DrawArrays()
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.
Please consult an OpenGL reference manual for more information.
#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 and the buffer object's data store is currently mapped.
#GL_INVALID_OPERATION
is generated if glDrawArrays is executed between the execution of glBegin and the corresponding glEnd.