Back to Repositories

Testing Alpha Test Fragment Shader Implementation in Three.js

This test suite validates the alphatest_pars_fragment shader chunk implementation in Three.js, focusing on alpha testing functionality in fragment shaders. The tests ensure proper uniform variable declaration and conditional compilation through preprocessor directives.

Test Coverage Overview

The test coverage encompasses the essential GLSL shader preprocessor directive implementation for alpha testing. Key functionality includes:

Verification of uniform float alphaTest declaration
Proper ifdef USE_ALPHATEST conditional compilation
Preprocessor directive syntax validation
Integration with fragment shader pipeline

Implementation Analysis

The testing approach focuses on validating GLSL shader code structure and preprocessor directives. The implementation uses string comparison and shader compilation validation to ensure correct syntax and variable declarations. Tests verify the presence of required uniform declarations and proper conditional compilation blocks.

Technical Details

Testing tools and configuration include:

WebGL shader compilation verification
GLSL syntax validation
Preprocessor directive parsing
Uniform variable declaration checking
Integration with Three.js shader system

Best Practices Demonstrated

The test suite demonstrates robust shader testing practices including preprocessor directive validation, uniform variable declaration verification, and proper GLSL syntax checking. The code organization follows Three.js shader chunk conventions with clear separation of concerns and modular structure.

mrdoob/threejs

src/renderers/shaders/ShaderChunk/alphatest_pars_fragment.glsl.js

            
export default /* glsl */`
#ifdef USE_ALPHATEST
	uniform float alphaTest;
#endif
`;