mediump float;

out vec4 my_FragColor;
uniform sampler2D u_sampler;
uniform vec2 u_texCoord;
uniform vec2 u_dPdx;
uniform vec2 u_dPdy;

void main() {
    ivec2 offset = ivec2(0);
    my_FragColor = textureGradOffset(u_sampler, u_texCoord, u_dPdx, u_dPdy, offset);
}
</script>
<script id="fshaderTextureProjGradOffset" type="x-shader/x-fragment">#version 300 es
precision mediump float;

out vec4 my_FragColor;
uniform sampler2D u_sampler;
uniform vec4 u_texCoord;
uniform vec2 u_dPdx;
uniform vec2 u_dPdy;

void 