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1 // Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file | |
2 // for details. All rights reserved. Use of this source code is governed by a | |
3 // BSD-style license that can be found in the LICENSE file. | |
4 // | |
5 // This sample is based upon the Ray Tracer sample by Jonas Sicking at: | |
6 // http://www.khronos.org/webgl/wiki/Demo_Repository | |
7 | |
8 /** | |
9 * A sample GL application. | |
10 */ | |
11 library raytrace; | |
12 | |
13 import 'gl.dart'; | |
14 import 'dart:math' as Math; | |
15 | |
16 // Note: The first line of the fragment shader ("precision mediump float") | |
17 // is not portable. It is required for WebGL and OpenGL ES. Desktop OpenGL | |
18 // does not use precision specifiers. Some desktop systems treat this as a | |
19 // no-op and some treat it as a syntax error. In particular, this line needs | |
20 // to be removed to this this shader on a MAc. | |
21 const FRAGMENT_PROGRAM = """ | |
22 precision mediump float; | |
23 | |
24 const vec3 lightDir = vec3(0.577350269, 0.577350269, -0.577350269); | |
25 varying vec3 vPosition; | |
26 uniform vec3 cameraPos; | |
27 uniform vec3 sphere1Center; | |
28 uniform vec3 sphere2Center; | |
29 uniform vec3 sphere3Center; | |
30 | |
31 bool intersectSphere(vec3 center, vec3 lStart, vec3 lDir, | |
32 out float dist) { | |
33 vec3 c = center - lStart; | |
34 float b = dot(lDir, c); | |
35 float d = b*b - dot(c, c) + 1.0; | |
36 if (d < 0.0) { | |
37 dist = 10000.0; | |
38 return false; | |
39 } | |
40 | |
41 dist = b - sqrt(d); | |
42 if (dist < 0.0) { | |
43 dist = 10000.0; | |
44 return false; | |
45 } | |
46 | |
47 return true; | |
48 } | |
49 | |
50 vec3 lightAt(vec3 N, vec3 V, vec3 color) { | |
51 vec3 L = lightDir; | |
52 vec3 R = reflect(-L, N); | |
53 | |
54 float c = 0.3 + 0.4 * pow(max(dot(R, V), 0.0), 30.0) + 0.7 * dot(L, N); | |
55 | |
56 if (c > 1.0) { | |
57 return mix(color, vec3(1.6, 1.6, 1.6), c - 1.0); | |
58 } | |
59 | |
60 return c * color; | |
61 } | |
62 | |
63 bool intersectWorld(vec3 lStart, vec3 lDir, out vec3 pos, | |
64 out vec3 normal, out vec3 color) { | |
65 float d1, d2, d3; | |
66 bool h1, h2, h3; | |
67 | |
68 h1 = intersectSphere(sphere1Center, lStart, lDir, d1); | |
69 h2 = intersectSphere(sphere2Center, lStart, lDir, d2); | |
70 h3 = intersectSphere(sphere3Center, lStart, lDir, d3); | |
71 | |
72 if (h1 && d1 < d2 && d1 < d3) { | |
73 pos = lStart + d1 * lDir; | |
74 normal = pos - sphere1Center; | |
75 color = vec3(0.0, 0.0, 0.9); | |
76 if (fract(pos.x / 1.5) > 0.5 ^^ | |
77 fract(pos.y / 1.5) > 0.5 ^^ | |
78 fract(pos.z / 1.5) > 0.5) { | |
79 color = vec3(1.0, 0.0, 1.0); | |
80 } | |
81 else { | |
82 color = vec3(1.0, 1.0, 0.0); | |
83 } | |
84 } | |
85 else if (h2 && d2 < d3) { | |
86 pos = lStart + d2 * lDir; | |
87 normal = pos - sphere2Center; | |
88 color = vec3(0.9, mod(normal.y * 2.5, 1.0), 0.0); | |
89 } | |
90 else if (h3) { | |
91 pos = lStart + d3 * lDir; | |
92 normal = pos - sphere3Center; | |
93 color = vec3(0.0, clamp(sphere3Center.y/1.5, 0.0, 0.9), | |
94 clamp(0.9 - sphere3Center.y/1.5, 0.0, 0.9)); | |
95 } | |
96 else if (lDir.y < -0.01) { | |
97 pos = lStart + ((lStart.y + 2.7) / -lDir.y) * lDir; | |
98 if (pos.x*pos.x + pos.z*pos.z > 30.0) { | |
99 return false; | |
100 } | |
101 normal = vec3(0.0, 1.0, 0.0); | |
102 if (fract(pos.x / 5.0) > 0.5 == fract(pos.z / 5.0) > 0.5) { | |
103 color = vec3(1.0); | |
104 } | |
105 else { | |
106 color = vec3(0.0); | |
107 } | |
108 } | |
109 else { | |
110 return false; | |
111 } | |
112 | |
113 return true; | |
114 } | |
115 | |
116 void main(void) | |
117 { | |
118 vec3 cameraDir = normalize(vPosition - cameraPos); | |
119 | |
120 vec3 p1, norm, p2; | |
121 vec3 col, colT, colM, col3; | |
122 if (intersectWorld(cameraPos, cameraDir, p1, | |
123 norm, colT)) { | |
124 col = lightAt(norm, -cameraDir, colT); | |
125 colM = (colT + vec3(0.2)) / 1.2; | |
126 cameraDir = reflect(cameraDir, norm); | |
127 if (intersectWorld(p1, cameraDir, p2, norm, colT)) { | |
128 col += lightAt(norm, -cameraDir, colT) * colM; | |
129 colM *= (colT + vec3(0.2)) / 1.2; | |
130 cameraDir = reflect(cameraDir, norm); | |
131 if (intersectWorld(p2, cameraDir, p1, norm, colT)) { | |
132 col += lightAt(norm, -cameraDir, colT) * colM; | |
133 } | |
134 } | |
135 | |
136 gl_FragColor = vec4(col, 1.0); | |
137 } | |
138 else { | |
139 gl_FragColor = vec4(0.0, 0.0, 0.0, 1.0); | |
140 } | |
141 } | |
142 """; | |
143 | |
144 const VERTEX_PROGRAM = """ | |
145 attribute vec2 aVertexPosition; | |
146 attribute vec3 aPlotPosition; | |
147 | |
148 varying vec3 vPosition; | |
149 | |
150 void main(void) | |
151 { | |
152 gl_Position = vec4(aVertexPosition, 1.0, 1.0); | |
153 vPosition = aPlotPosition; | |
154 } | |
155 """; | |
156 | |
157 loadShader(final type, final program) { | |
158 final shader = gl.createShader(type); | |
159 gl.shaderSource(shader, program); | |
160 gl.compileShader(shader); | |
161 if (gl.getShaderParameter(shader, WebGLRenderingContext.COMPILE_STATUS) != tru
e) { | |
162 final error = gl.getShaderInfoLog(shader); | |
163 log(error); | |
164 throw new Exception("Shader compilation error: $error"); | |
165 } | |
166 | |
167 return shader; | |
168 } | |
169 | |
170 var shaderProgram; | |
171 var aVertexPosition; | |
172 var aPlotPosition; | |
173 var cameraPos; | |
174 var sphere1Center; | |
175 var sphere2Center; | |
176 var sphere3Center; | |
177 var ratio; | |
178 | |
179 void initShaders() { | |
180 var vertexShader = loadShader(WebGLRenderingContext.VERTEX_SHADER, | |
181 VERTEX_PROGRAM); | |
182 var fragmentShader = loadShader(WebGLRenderingContext.FRAGMENT_SHADER, | |
183 FRAGMENT_PROGRAM); | |
184 | |
185 shaderProgram = gl.createProgram(); | |
186 if (shaderProgram == 0) { | |
187 throw new Exception("Could not create program."); | |
188 } | |
189 | |
190 gl.attachShader(shaderProgram, vertexShader); | |
191 gl.attachShader(shaderProgram, fragmentShader); | |
192 gl.linkProgram(shaderProgram); | |
193 | |
194 if (gl.getProgramParameter(shaderProgram, WebGLRenderingContext.LINK_STATUS) !
= true) { | |
195 final error = gl.getProgramInfoLog(shaderProgram); | |
196 throw new Exception("Program compilation error: $error"); | |
197 } | |
198 | |
199 gl.useProgram(shaderProgram); | |
200 | |
201 aVertexPosition = gl.getAttribLocation(shaderProgram, "aVertexPosition"); | |
202 gl.enableVertexAttribArray(aVertexPosition); | |
203 | |
204 aPlotPosition = gl.getAttribLocation(shaderProgram, "aPlotPosition"); | |
205 gl.enableVertexAttribArray(aPlotPosition); | |
206 | |
207 cameraPos = gl.getUniformLocation(shaderProgram, "cameraPos"); | |
208 sphere1Center = gl.getUniformLocation(shaderProgram, "sphere1Center"); | |
209 sphere2Center = gl.getUniformLocation(shaderProgram, "sphere2Center"); | |
210 sphere3Center = gl.getUniformLocation(shaderProgram, "sphere3Center"); | |
211 } | |
212 | |
213 // TODO(gram): This should go away at some point. For now it is a kludge | |
214 // to allow us to run same .dart file with WebGL and natively; the WebGL | |
215 // version will set this to true. | |
216 var wrapVertexArray = false; | |
217 | |
218 wrapVertices(a) => wrapVertexArray ? (new Float32Array.fromList(a)) : a; | |
219 | |
220 void initBuffers() { | |
221 var vertexPositionBuffer = gl.createBuffer(); | |
222 gl.bindBuffer(WebGLRenderingContext.ARRAY_BUFFER, vertexPositionBuffer); | |
223 var vertices = [ | |
224 1.0, 1.0, | |
225 -1.0, 1.0, | |
226 1.0, -1.0, | |
227 -1.0, -1.0, | |
228 ]; | |
229 | |
230 gl.bufferData(WebGLRenderingContext.ARRAY_BUFFER, wrapVertices(vertices), | |
231 WebGLRenderingContext.STATIC_DRAW); | |
232 gl.bindBuffer(WebGLRenderingContext.ARRAY_BUFFER, vertexPositionBuffer); | |
233 gl.vertexAttribPointer(aVertexPosition, 2, WebGLRenderingContext.FLOAT, | |
234 false,0, 0); | |
235 | |
236 var plotPositionBuffer = gl.createBuffer(); | |
237 gl.bindBuffer(WebGLRenderingContext.ARRAY_BUFFER, plotPositionBuffer); | |
238 gl.vertexAttribPointer(aPlotPosition, 3, WebGLRenderingContext.FLOAT, | |
239 false, 0, 0); | |
240 } | |
241 | |
242 class Vector { | |
243 var x; | |
244 var y; | |
245 var z; | |
246 Vector(this.x, this.y, this.z); | |
247 } | |
248 | |
249 // TODO(gram): This should be using vector_math. | |
250 crossProd(v1, v2) => | |
251 new Vector(v1.y*v2.z - v2.y*v1.z, | |
252 v1.z*v2.x - v2.z*v1.x, | |
253 v1.x*v2.y - v2.x*v1.y); | |
254 | |
255 Vector normalize(v) { | |
256 var l = 1 / Math.sqrt(v.x*v.x + v.y*v.y + v.z*v.z); | |
257 return new Vector( v.x*l, v.y*l, v.z*l ); | |
258 } | |
259 | |
260 vectAdd(v1, v2) => new Vector( v1.x + v2.x, v1.y + v2.y, v1.z + v2.z ); | |
261 | |
262 vectSub(v1, v2) => new Vector( v1.x - v2.x, v1.y - v2.y, v1.z - v2.z ); | |
263 | |
264 vectMul(v, l) => new Vector( v.x*l, v.y*l, v.z*l ); | |
265 | |
266 void pushVec(v, arr) { | |
267 arr.addAll([v.x, v.y, v.z]); | |
268 } | |
269 | |
270 var t = 0; | |
271 | |
272 void drawScene() { | |
273 var x1 = Math.sin(t * 1.1) * 1.5; | |
274 var y1 = Math.cos(t * 1.3) * 1.5; | |
275 var z1 = Math.sin(t + Math.PI/3) * 1.5; | |
276 var x2 = Math.cos(t * 1.2) * 1.5; | |
277 var y2 = Math.sin(t * 1.4) * 1.5; | |
278 var z2 = Math.sin(t*1.25 - Math.PI/3) * 1.5; | |
279 var x3 = Math.cos(t * 1.15) * 1.5; | |
280 var y3 = Math.sin(t * 1.37) * 1.5; | |
281 var z3 = Math.sin(t*1.27) * 1.5; | |
282 | |
283 var cameraFrom = new Vector( | |
284 Math.sin(t * 0.4) * 18, | |
285 Math.sin(t * 0.13) * 5 + 5, | |
286 Math.cos(t * 0.4) * 18 ); | |
287 var cameraTo = new Vector(0.0, 0.0, 0.0); | |
288 var cameraPersp = 6.0; | |
289 var up = new Vector(0.0, 1.0, 0.0); | |
290 var cameraDir = normalize(vectSub(cameraTo, cameraFrom)); | |
291 | |
292 var cameraLeft = normalize(crossProd(cameraDir, up)); | |
293 var cameraUp = normalize(crossProd(cameraLeft, cameraDir)); | |
294 // cameraFrom + cameraDir * cameraPersp | |
295 var cameraCenter = vectAdd(cameraFrom, vectMul(cameraDir, cameraPersp)); | |
296 | |
297 // cameraCenter + cameraUp + cameraLeft * ratio | |
298 var cameraTopLeft = vectAdd(vectAdd(cameraCenter, cameraUp), | |
299 vectMul(cameraLeft, ratio)); | |
300 var cameraBotLeft = vectAdd(vectSub(cameraCenter, cameraUp), | |
301 vectMul(cameraLeft, ratio)); | |
302 var cameraTopRight = vectSub(vectAdd(cameraCenter, cameraUp), | |
303 vectMul(cameraLeft, ratio)); | |
304 var cameraBotRight = vectSub(vectSub(cameraCenter, cameraUp), | |
305 vectMul(cameraLeft, ratio)); | |
306 | |
307 var corners = []; | |
308 pushVec(cameraTopRight, corners); | |
309 pushVec(cameraTopLeft, corners); | |
310 pushVec(cameraBotRight, corners); | |
311 pushVec(cameraBotLeft, corners); | |
312 | |
313 gl.bufferData(WebGLRenderingContext.ARRAY_BUFFER, wrapVertices(corners), | |
314 WebGLRenderingContext.STATIC_DRAW); | |
315 | |
316 gl.uniform3f(cameraPos, cameraFrom.x, cameraFrom.y, cameraFrom.z); | |
317 gl.uniform3f(sphere1Center, x1, y1, z1); | |
318 gl.uniform3f(sphere2Center, x2, y2, z2); | |
319 gl.uniform3f(sphere3Center, x3, y3, z3); | |
320 | |
321 gl.drawArrays(WebGLRenderingContext.TRIANGLE_STRIP, 0, 4); | |
322 | |
323 t += 0.03; | |
324 if (t > Math.PI * 200) { | |
325 t -= Math.PI * 200; | |
326 } | |
327 } | |
328 | |
329 void setup(int width, int height) { | |
330 initShaders(); | |
331 gl.clearColor(0.0, 0.0, 0.0, 1.0); | |
332 gl.clearDepth(1.0); | |
333 initBuffers(); | |
334 resize(width, height); | |
335 } | |
336 | |
337 void resize(int width, int height) { | |
338 ratio = width / height; | |
339 gl.viewport(0, 0, width, height); | |
340 t -= 0.03; | |
341 drawScene(); | |
342 } | |
343 | |
344 void update() { | |
345 drawScene(); | |
346 } | |
347 | |
348 /* | |
349 TODO(gram): below are the current entry points for input events for the | |
350 native code version. We need to integrate these somehow with the WebGL | |
351 version: | |
352 | |
353 onMotionDown(num when, num x, num y) {} | |
354 onMotionUp(num when, num x, num y) {} | |
355 onMotionMove(num when, num x, num y) {} | |
356 onMotionCancel(num when, num x, num y) {} | |
357 onMotionOutside(num when, num x, num y) {} | |
358 onMotionPointerDown(num when, num x, num y) {} | |
359 onMotionPointerUp(num when, num x, num y) {} | |
360 onKeyDown(num when, int flags, int keycode, int metastate, int repeat) {} | |
361 onKeyUp(num when, int flags, int keycode, int metastate, int repeat) {} | |
362 onKeyMultiple(num when, int flags, int keycode, int metastate, int repeat) { | |
363 } | |
364 */ | |
365 | |
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