drawBuffers method

dynamic drawBuffers(dynamic renderTarget, dynamic framebuffer)

Implementation

drawBuffers(renderTarget, framebuffer) {
  dynamic drawBuffers = defaultDrawbuffers;

  var needsUpdate = false;

  if (renderTarget != null) {
    drawBuffers = currentDrawbuffers.get(framebuffer);

    if (drawBuffers == null) {
      drawBuffers = [];
      currentDrawbuffers.set(framebuffer, drawBuffers);
    }

    if (renderTarget.isWebGLMultipleRenderTargets) {
      var textures = renderTarget.texture;

      if (drawBuffers.length != textures.length || drawBuffers[0] != gl.COLOR_ATTACHMENT0) {
        for (var i = 0, il = textures.length; i < il; i++) {
          drawBuffers[i] = gl.COLOR_ATTACHMENT0 + i;
        }

        drawBuffers.length = textures.length;

        needsUpdate = true;
      }
    } else {
      if (drawBuffers.length == 0 || drawBuffers[0] != gl.COLOR_ATTACHMENT0) {
        if (drawBuffers.length == 0) {
          drawBuffers.add(gl.COLOR_ATTACHMENT0);
        } else {
          drawBuffers[0] = gl.COLOR_ATTACHMENT0;
        }

        drawBuffers.length = 1;

        needsUpdate = true;
      }
    }
  } else {
    if (drawBuffers.length == 0 || drawBuffers[0] != gl.BACK) {
      if (drawBuffers.length == 0) {
        drawBuffers.add(gl.BACK);
      } else {
        drawBuffers[0] = gl.BACK;
      }

      drawBuffers.length = 1;

      needsUpdate = true;
    }
  }

  if (needsUpdate) {
    if (capabilities.isWebGL2) {
      gl.drawBuffers(List<int>.from(drawBuffers));
    } else {
      extensions.get('WEBGL_draw_buffers').drawBuffersWEBGL(List<int>.from(drawBuffers));
    }
  }
}