Source: Palette/Shader.js

  1. /* global WebGLShader */
  2. /**
  3. * @classdesc Abstraction of shader references to allow easy manipulation.
  4. * @class Palette.Shader
  5. * @description Initialise and compile a valid Source Object into a Shader.
  6. * @param {WebGLRenderingContext} gl - The context the shader will belong to and be compiled by.
  7. * @param {string} name - The name the shader object will be referred to by.
  8. * @param {number} type - The class of the shader contained, either Palette.Shader.VS or Palette.Shader.FS.
  9. * @param {string} source - The source code to compile the shader from.
  10. * @param {WebGLRenderingContext} gl - The context the shaders of this program will belong to and be compiled by.
  11. * @param {object} [attrs] - The array which contains attribute names and default values, as an array of 3-tuples.
  12. * @author FelixMcFelix (Kyle S.)
  13. */
  14. Palette.Shader = function(gl, name, type, source, attrs){
  15. 	/**
  16. 	* The shader's name.
  17. 	* @name Palette.Shader#name
  18. 	* @type String
  19. 	* @protected
  20. 	* @readonly
  21. 	*/
  22. 	this.name = name;
  24. 	/**
  25. 	* The type of shader, either Palette.Shader.VS or Palette.Shader.FS for objects.
  26. 	* @name Palette.Shader#type
  27. 	* @type int
  28. 	* @protected
  29. 	* @readonly
  30. 	*/
  31. 	this.type = type;
  33. 	/**
  34. 	* The shader's attached context.
  35. 	* @name Palette.Shader#context
  36. 	* @type WebGLRenderingContext
  37. 	* @protected
  38. 	* @readonly
  39. 	*/
  40. 	this.context = gl;
  42. 	/**
  43. 	* The shader's attribute array.
  44. 	* @name Palette.Shader#attrs
  45. 	* @type Array[]
  46. 	* @protected
  47. 	* @readonly
  48. 	*/
  49. 	this.attrs = attrs;
  51. 	/**
  52. 	* The reference to the compiled shader in the WebGLRenderingContext.
  53. 	* @name Palette.Shader#shader
  54. 	* @type WebGLShader
  55. 	* @protected
  56. 	* @readonly
  57. 	*/
  58. 	this.shader = null;
  60. 	/**
  61. 	* Has the shader attempted compilation yet?
  62. 	* @name Palette.Shader#compiled
  63. 	* @type Boolean
  64. 	* @private
  65. 	* @readonly
  66. 	*/
  67. 	this.compiled = false;
  69. 	this.bakeShader(source);
  70. };
  72. Palette.Shader.prototype = {
  73. 	/**
  74. 	* Compile shader code from a source string. Once compiled, you cannot recompile.
  75. 	* @method Palette.Shader#bakeShader
  76. 	* @protected
  77. 	* @param {string} source - The source code to compile and attach to this shader object.
  78. 	* @return {boolean} True if successful, false if unsuccessful.
  79. 	*/
  80. 	bakeShader: function(source){
  81. 		if (this.compiled){return null;}
  83. 		this.compiled = true;
  85. 		switch(this.type){
  86. 			case Palette.Shader.VS:
  87. 				this.shader = this.context.createShader(this.context.VERTEX_SHADER);
  88. 				break;
  89. 			case Palette.Shader.FS:
  90. 				this.shader = this.context.createShader(this.context.FRAGMENT_SHADER);
  91. 				break;
  92. 			default:
  93. 				return false;
  94. 		}
  96. 		this.context.shaderSource(this.shader, source);
  97. 		this.context.compileShader(this.shader);
  98. 		if (!this.context.getShaderParameter(this.shader, this.context.COMPILE_STATUS)) {
  99. 			alert("An error occurred compiling the shaders: " + this.context.getShaderInfoLog(this.shader));
  100. 			return false;
  101. 		}
  103. 		return true;
  104. 	}
  105. };
  107. Palette.Shader.VS		= 0;
  108. Palette.Shader.FS		= 1;
  109. Palette.Shader.LIST		= 2;
  111. Palette.Shader.prototype.constructor = Palette.Shader;