Allow uniform bindings by name for FragmentShader #176417
Description
Description of problem
When using the FragmentShader API today one has to carefully count uniform offsets by hand in order to set uniforms. There should be a way to instead to set uniforms by name to make changing uniforms easier and for easier debugging.
Example
shader
uniform float uScale;
uniform sampler2D uTexture;
uniform vec2 uMagnitude;
uniform vec4 uColor;today
Generate dart code for shaders that has the uniform indices as constants.
shader.setFloat(0, 23); // uScale
shader.setFloat(1, 114); // uMagnitude x
shader.setFloat(2, 83); // uMagnitude y
shader.setFloat(3, color.red / 255 * color.opacity); // uColor r
shader.setFloat(4, color.green / 255 * color.opacity); // uColor g
shader.setFloat(5, color.blue / 255 * color.opacity); // uColor b
shader.setFloat(6, color.opacity); // uColor a
shader.setImageSampler(0, image);proposal
shader.setFloat(SHADER_USCALE, 23);
shader.setFloat(SHADER_UMAGNITUDE_X, 114);
shader.setFloat(SHADER_UMAGNITUDE_Y, 83);
shader.setFloat(SHADER_UCOLOR_RED, color.red / 255 * color.opacity);
shader.setFloat(SHADER_UCOLOR_GREEN, color.green / 255 * color.opacity);
shader.setFloat(SHADER_UCOLOR_BLUE, color.blue / 255 * color.opacity);
shader.setFloat(SHADER_UCOLOR_ALPHA, color.opacity);
shader.setImageSampler(SHADER_UTEXTURE, image);Alternatives considered
runtime access
shader.setFloat('uScale', 23);
shader.setFloat('uMagnitude', 114, 0);
shader.setFloat('uMagnitude', 83, 1);Having compile time checks for the validity of uniform names is a better user experience and better performance.