WebGLRenderingContext: drawArrays() method
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
The WebGLRenderingContext.drawArrays()
method of the WebGL API renders primitives from array data.
Syntax
js
drawArrays(mode, first, count)
Parameters
mode
-
A
GLenum
specifying the type primitive to render. Possible values are:gl.POINTS
: Draws a single dot.gl.LINE_STRIP
: Draws a straight line to the next vertex.-
gl.LINE_LOOP
: Draws a straight line to the next vertex, and connects the last vertex back to the first. gl.LINES
: Draws a line between a pair of vertices.gl.TRIANGLE_STRIP
gl.TRIANGLE_FAN
gl.TRIANGLES
: Draws a triangle for a group of three vertices.
Note: If
mode
isPOINTS
,gl_PointSize
may need to be set fordrawArrays
to render, as its value is unknown if not explicitly written. Only some GPUs set its default as1.0
. first
-
A
GLint
specifying the starting index in the array of vector points. count
-
A
GLsizei
specifying the number of indices to be rendered.
Return value
None (undefined
).
Exceptions
-
If
mode
is not one of the accepted values, agl.INVALID_ENUM
error is thrown. -
If
first
orcount
are negative, agl.INVALID_VALUE
error is thrown. -
if
gl.CURRENT_PROGRAM
isnull
, agl.INVALID_OPERATION
error is thrown.
Examples
js
gl.drawArrays(gl.POINTS, 0, 8);
Specifications
Specification |
---|
WebGL Specification # 5.14.11 |
Browser compatibility
BCD tables only load in the browser
See also
WebGLRenderingContext.drawElements()
ext.drawArraysInstancedANGLE()
ext.drawElementsInstancedANGLE()
ext.vertexAttribDivisorANGLE()
WebGL2RenderingContext.drawArraysInstanced()
WebGL2RenderingContext.drawElementsInstanced()
WebGL2RenderingContext.vertexAttribDivisor()
WEBGL_multi_draw.multiDrawArraysWEBGL()