// Light direction (normalized)
gl.glUniform3f(_lightDirectionLoc, 0.0f, 0.0f, -1.0f);
// Ambient light color
gl.glUniform3f(_lightAmbientLoc, 0.2f, 0.2f, 0.2f);
// Diffuse light color
gl.glUniform3f(_lightDiffuseLoc, 1.0f, 1.0f, 1.0f);
// Load texture