1 /******************************************************************************* 2 * Copyright 2011 See AUTHORS file. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 ******************************************************************************/ 16 17 package com.google.gwt.webgl.client; 18 19 import static com.google.gwt.webgl.client.WebGLRenderingContext.*; 20 21 public class WebGLUtil { 22 23 public static float[] createPerspectiveMatrix (int fieldOfViewVertical, float aspectRatio, float minimumClearance, 24 float maximumClearance) { 25 double fieldOfViewInRad = fieldOfViewVertical * Math.PI / 180.0; 26 return new float[] {(float)(Math.tan(fieldOfViewInRad) / aspectRatio), 0, 0, 0, 0, 27 (float)(1 / Math.tan(fieldOfViewVertical * Math.PI / 180.0)), 0, 0, 0, 0, 28 (minimumClearance + maximumClearance) / (minimumClearance - maximumClearance), -1, 0, 0, 29 2 * minimumClearance * maximumClearance / (minimumClearance - maximumClearance), 0}; 30 } 31 32 public static WebGLProgram createShaderProgram (WebGLRenderingContext gl, String vertexSource, String fragmentSource) { 33 WebGLShader vertexShader = getShader(gl, VERTEX_SHADER, vertexSource); 34 WebGLShader fragmentShader = getShader(gl, FRAGMENT_SHADER, fragmentSource); 35 36 WebGLProgram shaderProgram = gl.createProgram(); 37 gl.attachShader(shaderProgram, fragmentShader); 38 gl.attachShader(shaderProgram, vertexShader); 39 gl.linkProgram(shaderProgram); 40 41 if (!gl.getProgramParameterb(shaderProgram, LINK_STATUS)) { 42 throw new RuntimeException("Could not initialize shaders"); 43 } 44 45 return shaderProgram; 46 } 47 48 private static WebGLShader getShader (WebGLRenderingContext gl, int shaderType, String source) { 49 WebGLShader shader = gl.createShader(shaderType); 50 gl.shaderSource(shader, source); 51 gl.compileShader(shader); 52 if (!gl.getShaderParameterb(shader, COMPILE_STATUS)) { 53 throw new RuntimeException(gl.getShaderInfoLog(shader)); 54 } 55 return shader; 56 } 57 } 58
