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webgl_materials_texture_canvas.html 3.8 KB

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  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <title>three.js webgl - materials - canvas texture</title>
  5. <meta charset="utf-8">
  6. <meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
  7. <style>
  8. body {
  9. margin: 0px;
  10. background-color: #050505;
  11. color: #fff;
  12. overflow: hidden;
  13. }
  14. a { color: #e00 }
  15. #info {
  16. position: absolute;
  17. top: 0px; width: 100%;
  18. color: #ffffff;
  19. padding: 5px;
  20. font-family: Monospace;
  21. font-size: 13px;
  22. text-align: center;
  23. z-index: 1000;
  24. }
  25. #drawing-canvas {
  26. position: absolute;
  27. background-color: #000000;
  28. top: 0px;
  29. right: 0px;
  30. z-index: 3000;
  31. cursor: crosshair;
  32. }
  33. </style>
  34. </head>
  35. <body>
  36. <div id="info">
  37. <a href="http://threejs.org" target="_blank" rel="noopener">three.js</a> - webgl - canvas as a texture
  38. <div>click and draw in the white box</div>
  39. </div>
  40. <canvas id="drawing-canvas" height="128" width="128"></canvas>
  41. <script src="../build/three.js"></script>
  42. <script src="js/Detector.js"></script>
  43. <script>
  44. if ( ! Detector.webgl ) Detector.addGetWebGLMessage();
  45. var camera, scene, renderer, mesh, material;
  46. var drawStartPos = new THREE.Vector2();
  47. init();
  48. setupCanvasDrawing();
  49. animate();
  50. function init() {
  51. camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 2000 );
  52. camera.position.z = 500;
  53. scene = new THREE.Scene();
  54. material = new THREE.MeshBasicMaterial();
  55. mesh = new THREE.Mesh( new THREE.BoxBufferGeometry( 200, 200, 200 ), material );
  56. scene.add( mesh );
  57. renderer = new THREE.WebGLRenderer( { antialias: true } );
  58. renderer.setPixelRatio( window.devicePixelRatio );
  59. renderer.setSize( window.innerWidth, window.innerHeight );
  60. document.body.appendChild( renderer.domElement );
  61. window.addEventListener( 'resize', onWindowResize, false );
  62. }
  63. // Sets up the drawing canvas and adds it as the material map
  64. function setupCanvasDrawing() {
  65. // get canvas and context
  66. var drawingCanvas = document.getElementById( 'drawing-canvas' );
  67. var drawingContext = drawingCanvas.getContext( '2d' );
  68. // draw white background
  69. drawingContext.fillStyle = '#FFFFFF';
  70. drawingContext.fillRect( 0, 0, 128, 128 );
  71. // set canvas as material.map (this could be done to any map, bump, displacement etc.)
  72. material.map = new THREE.Texture( drawingCanvas );
  73. material.map.needsUpdate = true;
  74. // set the variable to keep track of when to draw
  75. var paint = false;
  76. // add canvas event listeners
  77. drawingCanvas.addEventListener( 'mousedown', function( e ) {
  78. paint = true;
  79. drawStartPos.set( e.offsetX, e.offsetY );
  80. } );
  81. drawingCanvas.addEventListener( 'mousemove', function( e ) {
  82. if( paint ) draw( drawingContext, e.offsetX, e.offsetY );
  83. } );
  84. drawingCanvas.addEventListener( 'mouseup', function( e ) {
  85. paint = false;
  86. } );
  87. drawingCanvas.addEventListener( 'mouseleave', function( e ) {
  88. paint = false;
  89. } );
  90. }
  91. function draw( drawContext, x, y ) {
  92. drawContext.moveTo( drawStartPos.x, drawStartPos.y );
  93. drawContext.strokeStyle = '#000000';
  94. drawContext.lineTo( x, y );
  95. drawContext.stroke();
  96. // reset drawing start position to current position.
  97. drawStartPos.set( x, y );
  98. // need to flag the map as needing updating.
  99. material.map.needsUpdate = true;
  100. }
  101. function onWindowResize() {
  102. camera.aspect = window.innerWidth / window.innerHeight;
  103. camera.updateProjectionMatrix();
  104. renderer.setSize( window.innerWidth, window.innerHeight );
  105. }
  106. function animate() {
  107. requestAnimationFrame( animate );
  108. mesh.rotation.x += 0.01;
  109. mesh.rotation.y += 0.01;
  110. renderer.render( scene, camera );
  111. }
  112. </script>
  113. </body>
  114. </html>