Question

check out the following test:

http://binks.knobbits.org/webgl/texture3.html

It’s a simple test of cube textures. It also has a 2D texture in there for good measure.

I discovered that in some browsers (so far, chrome) The image is not displayed properly if I re-use the same texture unit for drawing the cube texture as for the 2D texture.

There is a checkbox at the bottom marked “Use separate texture units for the cube texture on the sphere and the 2D texture on the floor” that shows this.

Is this a bug in chrome or in my code?

Answer 1

I have ordered a bit the code of the drawing functions and now are working.

Square:

TexturedSquare.prototype.draw = function() {
    gl.bindBuffer(gl.ARRAY_BUFFER,this.v);
    gl.enableVertexAttribArray(gl.va_vertex);
    gl.enableVertexAttribArray(gl.va_normal);
    gl.enableVertexAttribArray(gl.va_tex1pos);
    gl.vertexAttribPointer(gl.va_vertex,4,gl.FLOAT,false,10*4,0);
    gl.vertexAttribPointer(gl.va_normal,4,gl.FLOAT,false,10*4,4*4);
    gl.vertexAttribPointer(gl.va_tex1pos,2,gl.FLOAT,false,10*4,4*8);

    gl.activeTexture(gl.TEXTURE0);
    gl.bindTexture(gl.TEXTURE_2D,this.texture);
    gl.bindTexture(gl.TEXTURE_CUBE_MAP,null);

    gl.uniform1i(shader.textures,1);
    gl.uniform1i(shader.texture1,0);
    gl.uniform1i(shader.cube_textures,0);
    gl.uniform1i(shader.cubeTexture0,1);

    gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER,this.e);
    gl.drawElements(gl.TRIANGLES,this.l,gl.UNSIGNED_SHORT,0);

    gl.disableVertexAttribArray(gl.va_tex1pos);
}

Sphere:

GLHTexturedSphere.prototype.draw = function() {
    gl.bindBuffer(gl.ARRAY_BUFFER,this.vbuf);
    gl.enableVertexAttribArray(gl.va_vertex);
    gl.enableVertexAttribArray(gl.va_normal);
    gl.enableVertexAttribArray(this.va_cubetex0pos);
    gl.vertexAttribPointer(gl.va_vertex,4,gl.FLOAT,false,8*4,0);
    gl.vertexAttribPointer(gl.va_normal,4,gl.FLOAT,false,8*4,4*4);
    gl.vertexAttribPointer(this.va_cubetex0pos,4,gl.FLOAT,false,8*4,4*4);

    gl.activeTexture(gl.TEXTURE0);
    gl.bindTexture(gl.TEXTURE_2D,null);
    gl.bindTexture(gl.TEXTURE_CUBE_MAP,this.texture);

    gl.uniform1i(shader.textures,0);
    gl.uniform1i(shader.texture1,1);
    gl.uniform1i(shader.cube_textures,1);
    gl.uniform1i(shader.cubeTexture0,0);

    gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER,this.ebuf);
    gl.drawElements(gl.TRIANGLES,this.l,gl.UNSIGNED_SHORT,0);

    gl.disableVertexAttribArray(gl.va_cubetex0pos);
}

Both of them are using now TEXTURE0. Please check WebGL states and uniform values.

Original code is a bit hard for me, sorry. But I think the problem is that texture1 and cubeTexture0 uniforms are been setted with the same value.