WEBGL_multi_draw: multiDrawArraysWEBGL() method

The WEBGL_multi_draw.multiDrawArraysWEBGL() method of the WebGL API renders multiple primitives from array data. It is identical to multiple calls to the gl.drawArrays() method.

Syntax

multiDrawArraysWEBGL(mode,
    firstsList, firstsOffset,
    countsList, countsOffset,
    drawCount)

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.

• firstsList

  • : An Int32Array or Array (of GLint) specifying a list of starting indices for the arrays of vector points.

• firstsOffset

  • : A GLuint defining the starting point into the firstsLists array.

• countsList

  • : An Int32Array or Array (of GLsizei) specifying a list of numbers of indices to be rendered.

• countsOffset

  • : A GLuint defining the starting point into the countsList array.

• drawCount

  • : A GLsizei specifying the number of instances of the range of elements to execute.

Return value

None.

Exceptions

• If mode is not one of the accepted values, a gl.INVALID_ENUM error is thrown.
• If drawCount or items in firstsList and countsList are negative, a gl.INVALID_VALUE error is thrown.
• if gl.CURRENT_PROGRAM is null, a gl.INVALID_OPERATION error is thrown.

Examples

const firsts = new Int32Array(/* … */);
const counts = new Int32Array(/* … */);
ext.multiDrawArraysWEBGL(gl.TRIANGLES, firsts, 0, counts, 0, firsts.length);

Specifications

Browser compatibility

See also

• WebGLRenderingContext.drawArrays()
• WebGL2RenderingContext.drawArraysInstanced()