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1 | /* globals window document mat4 */ | |
2 | ||
3 | const internals = { | |
4 | ||
5 | // Constants | |
6 | ||
7 | kEntrypointElementId: 'entrypoint', // The id of the canvas element where we will render | |
8 | kWidthRatio: 2.76, | |
9 | kHeightRatio: 1, | |
10 | kTargetVerticalResolution: 32 + Math.round(Math.random() * 1024), | |
11 | kFieldOfView: 45, | |
12 | kNearLimit: 0.1, | |
13 | kFarLimit: 100, | |
14 | kBackgroundColor: [0.811, 0.73, 0.48, 1.0], | |
15 | kRotationValues: [Math.random(), Math.random(), Math.random()], | |
16 | kFPS: 30, | |
17 | ||
18 | // Constants: Shaders | |
19 | ||
20 | kVertexShader: ` | |
21 | ||
22 | attribute vec4 aVertexPosition; | |
23 | attribute vec4 aColor; | |
24 | ||
25 | varying vec4 vColor; | |
26 | ||
27 | uniform mat4 uModelViewMatrix; | |
28 | uniform mat4 uProjectionMatrix; | |
29 | ||
30 | void main() { | |
31 | ||
32 | gl_Position = uProjectionMatrix * uModelViewMatrix * aVertexPosition; | |
33 | vColor = aColor; | |
34 | } | |
35 | `, | |
36 | ||
37 | kFragmentShader: ` | |
38 | ||
39 | precision mediump float; | |
40 | varying vec4 vColor; | |
41 | ||
42 | void main() { | |
43 | ||
44 | gl_FragColor = vColor; | |
45 | } | |
46 | `, | |
47 | ||
48 | // Properties: Animation | |
49 | ||
50 | currentTime: 0, | |
51 | ||
52 | // Runs on load, Initializes WebGL and starts the animation loop. | |
53 | ||
54 | onLoad() { | |
55 | ||
56 | ||
57 | const canvas = internals.initializeCanvas(); | |
58 | const { gl, programInfo, buffers } = internals.initializeWebGL(canvas); | |
59 | ||
60 | window.requestAnimationFrame(internals.animate.bind(this, gl, programInfo, buffers)); | |
61 | }, | |
62 | ||
63 | // Gets a canvas element and sets up resizing events. | |
64 | ||
65 | initializeCanvas() { | |
66 | ||
67 | const canvas = document.getElementById(internals.kEntrypointElementId); | |
68 | internals.resizeCanvas(canvas); | |
69 | window.addEventListener('resize', () => internals.resizeCanvas(canvas)); | |
70 | ||
71 | return canvas; | |
72 | }, | |
73 | ||
74 | // Given a canvas, it will initialize the webgl context and set up the shaders. | |
75 | ||
76 | initializeWebGL(canvas) { | |
77 | ||
78 | const gl = canvas.getContext('webgl', { | |
79 | preserveDrawingBuffer: true | |
80 | }); | |
81 | const shaderProgram = internals.initializeShaderProgram(gl, internals.kVertexShader, internals.kFragmentShader); | |
82 | ||
83 | const programInfo = { | |
84 | program: shaderProgram, | |
85 | attribLocations: { | |
86 | vertexPosition: gl.getAttribLocation(shaderProgram, 'aVertexPosition'), | |
87 | vertexColor: gl.getAttribLocation(shaderProgram, 'aColor') | |
88 | }, | |
89 | uniformLocations: { | |
90 | projectionMatrix: gl.getUniformLocation(shaderProgram, 'uProjectionMatrix'), | |
91 | modelViewMatrix: gl.getUniformLocation(shaderProgram, 'uModelViewMatrix') | |
92 | } | |
93 | }; | |
94 | ||
95 | const buffers = internals.initializeBuffers(gl); | |
96 | ||
97 | return { gl, programInfo, buffers }; | |
98 | }, | |
99 | ||
100 | // Methods: Canvas | |
101 | ||
102 | resizeCanvas(canvas) { | |
103 | ||
104 | let width = window.innerWidth; | |
105 | let height = Math.round(width * internals.kHeightRatio / internals.kWidthRatio); | |
106 | ||
107 | if (window.innerHeight < height) { | |
108 | height = window.innerHeight; | |
109 | width = Math.round(height * internals.kWidthRatio / internals.kHeightRatio); | |
110 | console.log(width, height); | |
111 | } | |
112 | ||
113 | canvas.style.width = `${width}px`; | |
114 | canvas.style.height = `${height}px`; | |
115 | ||
116 | canvas.width = internals.kTargetVerticalResolution * internals.kWidthRatio; | |
117 | canvas.height = internals.kTargetVerticalResolution; | |
118 | }, | |
119 | ||
120 | // Methods: Shader / GL Related | |
121 | ||
122 | initializeShaderProgram(gl, vertexShaderSource, fragmentShaderSource) { | |
123 | ||
124 | const vertexShader = internals.loadShader(gl, gl.VERTEX_SHADER, vertexShaderSource); | |
125 | const fragmentShader = internals.loadShader(gl, gl.FRAGMENT_SHADER, fragmentShaderSource); | |
126 | ||
127 | const shaderProgram = gl.createProgram(); | |
128 | gl.attachShader(shaderProgram, vertexShader); | |
129 | gl.attachShader(shaderProgram, fragmentShader); | |
130 | ||
131 | gl.linkProgram(shaderProgram); | |
132 | ||
133 | if (!gl.getProgramParameter(shaderProgram, gl.LINK_STATUS)) { | |
134 | console.error(`Unable to initialize shader program: ${gl.getProgramInfoLog(shaderProgram)}`); | |
135 | return null; | |
136 | } | |
137 | ||
138 | return shaderProgram; | |
139 | }, | |
140 | ||
141 | loadShader(gl, type, source) { | |
142 | ||
143 | const shader = gl.createShader(type); | |
144 | gl.shaderSource(shader, source); | |
145 | gl.compileShader(shader); | |
146 | ||
147 | if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) { | |
148 | console.error(`Unable to compile shader: ${gl.getShaderInfoLog(shader)}`); | |
149 | gl.deleteShader(shader); | |
150 | return null; | |
151 | } | |
152 | ||
153 | return shader; | |
154 | }, | |
155 | ||
156 | initializeBuffers(gl) { | |
157 | ||
158 | const positionBuffer = gl.createBuffer(); | |
159 | ||
160 | gl.bindBuffer(gl.ARRAY_BUFFER, positionBuffer); | |
161 | ||
162 | const positions = [ | |
163 | -1.0, 1.0, 1.0, // Front-top-left | |
164 | 1.0, 1.0, 1.0, // Front-top-right | |
165 | -1.0, -1.0, 1.0, // Front-bottom-left | |
166 | 1.0, -1.0, 1.0, // Front-bottom-right | |
167 | 1.0, -1.0, -1.0, // Back-bottom-right | |
168 | 1.0, 1.0, 1.0, // Front-top-right | |
169 | 1.0, 1.0, -1.0, // Back-top-right | |
170 | -1.0, 1.0, 1.0, // Front-top-left | |
171 | -1.0, 1.0, -1.0, // Back-top-left | |
172 | -1.0, -1.0, 1.0, // Front-bottom-left | |
173 | -1.0, -1.0, -1.0, // Back-bottom-left | |
174 | 1.0, -1.0, -1.0, // Back-bottom-right | |
175 | -1.0, 1.0, -1.0, // Back-top-left | |
176 | 1.0, 1.0, -1.0 // Back-top-right | |
177 | ]; | |
178 | ||
179 | gl.bufferData(gl.ARRAY_BUFFER, | |
180 | new Float32Array(positions), | |
181 | gl.STATIC_DRAW); | |
182 | ||
183 | return { | |
184 | position: positionBuffer | |
185 | }; | |
186 | }, | |
187 | ||
188 | // Methods: Utility | |
189 | ||
190 | createMatrix() { | |
191 | ||
192 | const matrix = mat4.create(); | |
193 | ||
194 | mat4.translate( | |
195 | matrix, | |
196 | matrix, | |
197 | [-0.0, 0.0, -6.0] | |
198 | ); | |
199 | ||
200 | return matrix; | |
201 | }, | |
202 | ||
203 | // Methods: Animation | |
204 | ||
205 | rotate(matrix) { | |
206 | ||
207 | mat4.rotate(internals.modelViewMatrix, internals.modelViewMatrix, internals.kRotationValues[0], [1, 0, 0]); | |
208 | mat4.rotate(internals.modelViewMatrix, internals.modelViewMatrix, internals.kRotationValues[1], [0, 1, 0]); | |
209 | mat4.rotate(internals.modelViewMatrix, internals.modelViewMatrix, internals.kRotationValues[2], [0, 0, 1]); | |
210 | }, | |
211 | ||
212 | drawScene(gl, programInfo, buffers) { | |
213 | ||
214 | gl.clearColor(...internals.kBackgroundColor); | |
215 | gl.clearDepth(1.0); | |
216 | gl.enable(gl.DEPTH_TEST); | |
217 | gl.depthFunc(gl.LEQUAL); | |
218 | ||
219 | const fieldOfView = internals.kFieldOfView * Math.PI / 180; | |
220 | const aspectRatio = internals.kWidthRatio / internals.kHeightRatio; | |
221 | const projectionMatrix = mat4.create(); | |
222 | ||
223 | mat4.perspective( | |
224 | projectionMatrix, | |
225 | fieldOfView, | |
226 | aspectRatio, | |
227 | internals.kNearLimit, | |
228 | internals.kFarLimit | |
229 | ); | |
230 | ||
231 | internals.modelViewMatrix = internals.modelViewMatrix || internals.createMatrix(); | |
232 | ||
233 | internals.rotate(internals.modelViewMatrix); | |
234 | ||
235 | { | |
236 | const numberOfComponents = 3; | |
237 | const type = gl.FLOAT; | |
238 | const normalize = false; | |
239 | const stride = 0; | |
240 | const offset = 0; | |
241 | ||
242 | gl.bindBuffer(gl.ARRAY_BUFFER, buffers.position); | |
243 | gl.vertexAttribPointer( | |
244 | programInfo.attribLocations.vertexPosition, | |
245 | numberOfComponents, | |
246 | type, | |
247 | normalize, | |
248 | stride, | |
249 | offset | |
250 | ); | |
251 | gl.enableVertexAttribArray(programInfo.attribLocations.vertexPosition); | |
252 | } | |
253 | ||
254 | { | |
255 | // ATTEMPT TO SEND COLOR DATA | |
256 | ||
257 | const colorBuffer = gl.createBuffer(); | |
258 | ||
259 | gl.bindBuffer(gl.ARRAY_BUFFER, colorBuffer); | |
260 | ||
261 | const colors = [ | |
262 | 1.0, 0.0, 0.5, 1.0, // Front-top-left | |
263 | 1.0, 0.3, 0.8, 1.0, // Front-top-right | |
264 | 1.0, 1.0, 0.7, 1.0, // Front-bottom-left | |
265 | 0.0, 0.3, 0.5, 1.0, // Front-bottom-right | |
266 | 0.0, 0.3, 0.5, 1.0, // Back-bottom-right | |
267 | 1.0, 0.3, 0.8, 1.0, // Front-top-right | |
268 | 1.0, 0.3, 0.8, 1.0, // Back-top-right | |
269 | 1.0, 0.0, 0.5, 1.0, // Front-top-left | |
270 | 1.0, 0.0, 0.5, 1.0, // Back-top-left | |
271 | 1.0, 1.0, 0.7, 1.0, // Front-bottom-left | |
272 | 1.0, 1.0, 0.7, 1.0, // Back-bottom-left | |
273 | 0.0, 0.3, 0.5, 1.0, // Back-bottom-right | |
274 | 1.0, 0.0, 0.5, 1.0, // Back-top-left | |
275 | 1.0, 0.3, 0.8, 1.0 // Back-top-right | |
276 | ]; | |
277 | ||
278 | gl.bufferData(gl.ARRAY_BUFFER, | |
279 | new Float32Array(colors), | |
280 | gl.STATIC_DRAW); | |
281 | ||
282 | const numberOfComponents = 4; | |
283 | const type = gl.FLOAT; | |
284 | const normalize = false; | |
285 | const stride = 0; | |
286 | const offset = 0; | |
287 | ||
288 | gl.bindBuffer(gl.ARRAY_BUFFER, colorBuffer); | |
289 | gl.vertexAttribPointer( | |
290 | programInfo.attribLocations.vertexColor, | |
291 | numberOfComponents, | |
292 | type, | |
293 | normalize, | |
294 | stride, | |
295 | offset | |
296 | ); | |
297 | gl.enableVertexAttribArray(programInfo.attribLocations.vertexColor); | |
298 | ||
299 | // END ATTEMPT | |
300 | } | |
301 | ||
302 | gl.useProgram(programInfo.program); | |
303 | ||
304 | gl.uniformMatrix4fv( | |
305 | programInfo.uniformLocations.projectionMatrix, | |
306 | false, | |
307 | projectionMatrix | |
308 | ); | |
309 | gl.uniformMatrix4fv( | |
310 | programInfo.uniformLocations.modelViewMatrix, | |
311 | false, | |
312 | internals.modelViewMatrix | |
313 | ); | |
314 | ||
315 | { | |
316 | const offset = 0; | |
317 | const vertexCount = 14; | |
318 | gl.drawArrays(gl.TRIANGLE_STRIP, offset, vertexCount); | |
319 | } | |
320 | }, | |
321 | ||
322 | animate(gl, programInfo, buffers, time) { | |
323 | ||
324 | const delta = time - internals.currentTime; | |
325 | const interval = 1000 / internals.kFPS; | |
326 | ||
327 | if (delta >= interval) { | |
328 | internals.drawScene(gl, programInfo, buffers, delta); | |
329 | internals.currentTime = time; | |
330 | } | |
331 | ||
332 | window.requestAnimationFrame(internals.animate.bind(this, gl, programInfo, buffers)); | |
333 | } | |
334 | }; | |
335 | ||
336 | window.addEventListener('load', internals.onLoad); |