i trying play around webgl , can render triangle in this plunker. try make full square changing...
//this... this.trianglevertexpositionbuffer.numitems = 3; // ... this.gl.drawarrays(this.gl.triangle_strip, 0, this.trianglevertexpositionbuffer.numitems); // this.. this.trianglevertexpositionbuffer.numitems = 4; this me should make square, however, triangle disappears. following warning...
gl error :gl_invalid_operation : gldrawarrays: attempt access out of range vertices in attribute 1 what missing here?
you need add color attribute fourth vertex aswell.
