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| 1 // Copyright 2013 The Chromium Authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 // This example program is based on Simple_VertexShader.c from: | |
| 6 | |
| 7 // | |
| 8 // Book: OpenGL(R) ES 2.0 Programming Guide | |
| 9 // Authors: Aaftab Munshi, Dan Ginsburg, Dave Shreiner | |
| 10 // ISBN-10: 0321502795 | |
| 11 // ISBN-13: 9780321502797 | |
| 12 // Publisher: Addison-Wesley Professional | |
| 13 // URLs: http://safari.informit.com/9780321563835 | |
| 14 // http://www.opengles-book.com | |
| 15 // | |
| 16 | |
| 17 #include "mojo/examples/sample_app/spinning_cube.h" | |
| 18 | |
| 19 #include <math.h> | |
| 20 #include <stdlib.h> | |
| 21 #include <string.h> | |
| 22 #include <GLES2/gl2.h> | |
| 23 #include <GLES2/gl2ext.h> | |
| 24 | |
| 25 namespace examples { | |
| 26 | |
| 27 namespace { | |
| 28 | |
| 29 const float kPi = 3.14159265359f; | |
| 30 | |
| 31 int GenerateCube(GLuint *vbo_vertices, | |
| 32 GLuint *vbo_indices) { | |
| 33 const int num_indices = 36; | |
| 34 | |
| 35 const GLfloat cube_vertices[] = { | |
| 36 -0.5f, -0.5f, -0.5f, | |
| 37 -0.5f, -0.5f, 0.5f, | |
| 38 0.5f, -0.5f, 0.5f, | |
| 39 0.5f, -0.5f, -0.5f, | |
| 40 -0.5f, 0.5f, -0.5f, | |
| 41 -0.5f, 0.5f, 0.5f, | |
| 42 0.5f, 0.5f, 0.5f, | |
| 43 0.5f, 0.5f, -0.5f, | |
| 44 -0.5f, -0.5f, -0.5f, | |
| 45 -0.5f, 0.5f, -0.5f, | |
| 46 0.5f, 0.5f, -0.5f, | |
| 47 0.5f, -0.5f, -0.5f, | |
| 48 -0.5f, -0.5f, 0.5f, | |
| 49 -0.5f, 0.5f, 0.5f, | |
| 50 0.5f, 0.5f, 0.5f, | |
| 51 0.5f, -0.5f, 0.5f, | |
| 52 -0.5f, -0.5f, -0.5f, | |
| 53 -0.5f, -0.5f, 0.5f, | |
| 54 -0.5f, 0.5f, 0.5f, | |
| 55 -0.5f, 0.5f, -0.5f, | |
| 56 0.5f, -0.5f, -0.5f, | |
| 57 0.5f, -0.5f, 0.5f, | |
| 58 0.5f, 0.5f, 0.5f, | |
| 59 0.5f, 0.5f, -0.5f, | |
| 60 }; | |
| 61 | |
| 62 const GLushort cube_indices[] = { | |
| 63 0, 2, 1, | |
| 64 0, 3, 2, | |
| 65 4, 5, 6, | |
| 66 4, 6, 7, | |
| 67 8, 9, 10, | |
| 68 8, 10, 11, | |
| 69 12, 15, 14, | |
| 70 12, 14, 13, | |
| 71 16, 17, 18, | |
| 72 16, 18, 19, | |
| 73 20, 23, 22, | |
| 74 20, 22, 21 | |
| 75 }; | |
| 76 | |
| 77 if (vbo_vertices) { | |
| 78 glGenBuffers(1, vbo_vertices); | |
| 79 glBindBuffer(GL_ARRAY_BUFFER, *vbo_vertices); | |
| 80 glBufferData(GL_ARRAY_BUFFER, | |
| 81 sizeof(cube_vertices), | |
| 82 cube_vertices, | |
| 83 GL_STATIC_DRAW); | |
| 84 glBindBuffer(GL_ARRAY_BUFFER, 0); | |
| 85 } | |
| 86 | |
| 87 if (vbo_indices) { | |
| 88 glGenBuffers(1, vbo_indices); | |
| 89 glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, *vbo_indices); | |
| 90 glBufferData(GL_ELEMENT_ARRAY_BUFFER, | |
| 91 sizeof(cube_indices), | |
| 92 cube_indices, | |
| 93 GL_STATIC_DRAW); | |
| 94 glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0); | |
| 95 } | |
| 96 | |
| 97 return num_indices; | |
| 98 } | |
| 99 | |
| 100 GLuint LoadShader(GLenum type, | |
| 101 const char* shader_source) { | |
| 102 GLuint shader = glCreateShader(type); | |
| 103 glShaderSource(shader, 1, &shader_source, NULL); | |
| 104 glCompileShader(shader); | |
| 105 | |
| 106 GLint compiled = 0; | |
| 107 glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled); | |
| 108 | |
| 109 if (!compiled) { | |
| 110 glDeleteShader(shader); | |
| 111 return 0; | |
| 112 } | |
| 113 | |
| 114 return shader; | |
| 115 } | |
| 116 | |
| 117 GLuint LoadProgram(const char* vertext_shader_source, | |
| 118 const char* fragment_shader_source) { | |
| 119 GLuint vertex_shader = LoadShader(GL_VERTEX_SHADER, | |
| 120 vertext_shader_source); | |
| 121 if (!vertex_shader) | |
| 122 return 0; | |
| 123 | |
| 124 GLuint fragment_shader = LoadShader(GL_FRAGMENT_SHADER, | |
| 125 fragment_shader_source); | |
| 126 if (!fragment_shader) { | |
| 127 glDeleteShader(vertex_shader); | |
| 128 return 0; | |
| 129 } | |
| 130 | |
| 131 GLuint program_object = glCreateProgram(); | |
| 132 glAttachShader(program_object, vertex_shader); | |
| 133 glAttachShader(program_object, fragment_shader); | |
| 134 | |
| 135 glLinkProgram(program_object); | |
| 136 | |
| 137 glDeleteShader(vertex_shader); | |
| 138 glDeleteShader(fragment_shader); | |
| 139 | |
| 140 GLint linked = 0; | |
| 141 glGetProgramiv(program_object, GL_LINK_STATUS, &linked); | |
| 142 | |
| 143 if (!linked) { | |
| 144 glDeleteProgram(program_object); | |
| 145 return 0; | |
| 146 } | |
| 147 | |
| 148 return program_object; | |
| 149 } | |
| 150 | |
| 151 class ESMatrix { | |
| 152 public: | |
| 153 GLfloat m[4][4]; | |
| 154 | |
| 155 ESMatrix() { | |
| 156 LoadZero(); | |
| 157 } | |
| 158 | |
| 159 void LoadZero() { | |
| 160 memset(this, 0x0, sizeof(ESMatrix)); | |
| 161 } | |
| 162 | |
| 163 void LoadIdentity() { | |
| 164 LoadZero(); | |
| 165 m[0][0] = 1.0f; | |
| 166 m[1][1] = 1.0f; | |
| 167 m[2][2] = 1.0f; | |
| 168 m[3][3] = 1.0f; | |
| 169 } | |
| 170 | |
| 171 void Multiply(ESMatrix* a, ESMatrix* b) { | |
| 172 ESMatrix result; | |
| 173 for (int i = 0; i < 4; ++i) { | |
| 174 result.m[i][0] = (a->m[i][0] * b->m[0][0]) + | |
| 175 (a->m[i][1] * b->m[1][0]) + | |
| 176 (a->m[i][2] * b->m[2][0]) + | |
| 177 (a->m[i][3] * b->m[3][0]); | |
| 178 | |
| 179 result.m[i][1] = (a->m[i][0] * b->m[0][1]) + | |
| 180 (a->m[i][1] * b->m[1][1]) + | |
| 181 (a->m[i][2] * b->m[2][1]) + | |
| 182 (a->m[i][3] * b->m[3][1]); | |
| 183 | |
| 184 result.m[i][2] = (a->m[i][0] * b->m[0][2]) + | |
| 185 (a->m[i][1] * b->m[1][2]) + | |
| 186 (a->m[i][2] * b->m[2][2]) + | |
| 187 (a->m[i][3] * b->m[3][2]); | |
| 188 | |
| 189 result.m[i][3] = (a->m[i][0] * b->m[0][3]) + | |
| 190 (a->m[i][1] * b->m[1][3]) + | |
| 191 (a->m[i][2] * b->m[2][3]) + | |
| 192 (a->m[i][3] * b->m[3][3]); | |
| 193 } | |
| 194 *this = result; | |
| 195 } | |
| 196 | |
| 197 void Frustum(float left, | |
| 198 float right, | |
| 199 float bottom, | |
| 200 float top, | |
| 201 float near_z, | |
| 202 float far_z) { | |
| 203 float delta_x = right - left; | |
| 204 float delta_y = top - bottom; | |
| 205 float delta_z = far_z - near_z; | |
| 206 | |
| 207 if ((near_z <= 0.0f) || | |
| 208 (far_z <= 0.0f) || | |
| 209 (delta_z <= 0.0f) || | |
| 210 (delta_y <= 0.0f) || | |
| 211 (delta_y <= 0.0f)) | |
| 212 return; | |
| 213 | |
| 214 ESMatrix frust; | |
| 215 frust.m[0][0] = 2.0f * near_z / delta_x; | |
| 216 frust.m[0][1] = frust.m[0][2] = frust.m[0][3] = 0.0f; | |
| 217 | |
| 218 frust.m[1][1] = 2.0f * near_z / delta_y; | |
| 219 frust.m[1][0] = frust.m[1][2] = frust.m[1][3] = 0.0f; | |
| 220 | |
| 221 frust.m[2][0] = (right + left) / delta_x; | |
| 222 frust.m[2][1] = (top + bottom) / delta_y; | |
| 223 frust.m[2][2] = -(near_z + far_z) / delta_z; | |
| 224 frust.m[2][3] = -1.0f; | |
| 225 | |
| 226 frust.m[3][2] = -2.0f * near_z * far_z / delta_z; | |
| 227 frust.m[3][0] = frust.m[3][1] = frust.m[3][3] = 0.0f; | |
| 228 | |
| 229 Multiply(&frust, this); | |
| 230 } | |
| 231 | |
| 232 void Perspective(float fov_y, float aspect, float near_z, float far_z) { | |
| 233 GLfloat frustum_h = tanf(fov_y / 360.0f * kPi) * near_z; | |
| 234 GLfloat frustum_w = frustum_h * aspect; | |
| 235 Frustum(-frustum_w, frustum_w, -frustum_h, frustum_h, near_z, far_z); | |
| 236 } | |
| 237 | |
| 238 void Translate(GLfloat tx, GLfloat ty, GLfloat tz) { | |
| 239 m[3][0] += m[0][0] * tx + m[1][0] * ty + m[2][0] * tz; | |
| 240 m[3][1] += m[0][1] * tx + m[1][1] * ty + m[2][1] * tz; | |
| 241 m[3][2] += m[0][2] * tx + m[1][2] * ty + m[2][2] * tz; | |
| 242 m[3][3] += m[0][3] * tx + m[1][3] * ty + m[2][3] * tz; | |
| 243 } | |
| 244 | |
| 245 void Rotate(GLfloat angle, GLfloat x, GLfloat y, GLfloat z) { | |
| 246 GLfloat mag = sqrtf(x * x + y * y + z * z); | |
| 247 | |
| 248 GLfloat sin_angle = sinf(angle * kPi / 180.0f); | |
| 249 GLfloat cos_angle = cosf(angle * kPi / 180.0f); | |
| 250 if (mag > 0.0f) { | |
| 251 GLfloat xx, yy, zz, xy, yz, zx, xs, ys, zs; | |
| 252 GLfloat one_minus_cos; | |
| 253 ESMatrix rotation; | |
| 254 | |
| 255 x /= mag; | |
| 256 y /= mag; | |
| 257 z /= mag; | |
| 258 | |
| 259 xx = x * x; | |
| 260 yy = y * y; | |
| 261 zz = z * z; | |
| 262 xy = x * y; | |
| 263 yz = y * z; | |
| 264 zx = z * x; | |
| 265 xs = x * sin_angle; | |
| 266 ys = y * sin_angle; | |
| 267 zs = z * sin_angle; | |
| 268 one_minus_cos = 1.0f - cos_angle; | |
| 269 | |
| 270 rotation.m[0][0] = (one_minus_cos * xx) + cos_angle; | |
| 271 rotation.m[0][1] = (one_minus_cos * xy) - zs; | |
| 272 rotation.m[0][2] = (one_minus_cos * zx) + ys; | |
| 273 rotation.m[0][3] = 0.0F; | |
| 274 | |
| 275 rotation.m[1][0] = (one_minus_cos * xy) + zs; | |
| 276 rotation.m[1][1] = (one_minus_cos * yy) + cos_angle; | |
| 277 rotation.m[1][2] = (one_minus_cos * yz) - xs; | |
| 278 rotation.m[1][3] = 0.0F; | |
| 279 | |
| 280 rotation.m[2][0] = (one_minus_cos * zx) - ys; | |
| 281 rotation.m[2][1] = (one_minus_cos * yz) + xs; | |
| 282 rotation.m[2][2] = (one_minus_cos * zz) + cos_angle; | |
| 283 rotation.m[2][3] = 0.0F; | |
| 284 | |
| 285 rotation.m[3][0] = 0.0F; | |
| 286 rotation.m[3][1] = 0.0F; | |
| 287 rotation.m[3][2] = 0.0F; | |
| 288 rotation.m[3][3] = 1.0F; | |
| 289 | |
| 290 Multiply(&rotation, this); | |
| 291 } | |
| 292 } | |
| 293 }; | |
| 294 | |
| 295 float RotationForTimeDelta(float delta_time) { | |
| 296 return delta_time * 40.0f; | |
| 297 } | |
| 298 | |
| 299 float RotationForDragDistance(float drag_distance) { | |
| 300 return drag_distance / 5; // Arbitrary damping. | |
| 301 } | |
| 302 | |
| 303 } // namespace | |
| 304 | |
| 305 class SpinningCube::GLState { | |
| 306 public: | |
| 307 GLState(); | |
| 308 | |
| 309 void OnGLContextLost(); | |
| 310 | |
| 311 GLfloat angle_; // Survives losing the GL context. | |
| 312 | |
| 313 GLuint program_object_; | |
| 314 GLint position_location_; | |
| 315 GLint mvp_location_; | |
| 316 GLint color_location_; | |
| 317 GLuint vbo_vertices_; | |
| 318 GLuint vbo_indices_; | |
| 319 int num_indices_; | |
| 320 ESMatrix mvp_matrix_; | |
| 321 }; | |
| 322 | |
| 323 SpinningCube::GLState::GLState() | |
| 324 : angle_(0) { | |
| 325 OnGLContextLost(); | |
| 326 } | |
| 327 | |
| 328 void SpinningCube::GLState::OnGLContextLost() { | |
| 329 program_object_ = 0; | |
| 330 position_location_ = 0; | |
| 331 mvp_location_ = 0; | |
| 332 color_location_ = 0; | |
| 333 vbo_vertices_ = 0; | |
| 334 vbo_indices_ = 0; | |
| 335 num_indices_ = 0; | |
| 336 } | |
| 337 | |
| 338 SpinningCube::SpinningCube() | |
| 339 : initialized_(false), | |
| 340 width_(0), | |
| 341 height_(0), | |
| 342 state_(new GLState()), | |
| 343 fling_multiplier_(1.0f), | |
| 344 direction_(1), | |
| 345 color_() { | |
| 346 state_->angle_ = 45.0f; | |
| 347 set_color(0.0, 1.0, 0.0); | |
| 348 } | |
| 349 | |
| 350 SpinningCube::~SpinningCube() { | |
| 351 if (!initialized_) | |
| 352 return; | |
| 353 if (state_->vbo_vertices_) | |
| 354 glDeleteBuffers(1, &state_->vbo_vertices_); | |
| 355 if (state_->vbo_indices_) | |
| 356 glDeleteBuffers(1, &state_->vbo_indices_); | |
| 357 if (state_->program_object_) | |
| 358 glDeleteProgram(state_->program_object_); | |
| 359 } | |
| 360 | |
| 361 void SpinningCube::Init(uint32_t width, uint32_t height) { | |
| 362 width_ = width; | |
| 363 height_ = height; | |
| 364 | |
| 365 const char vertext_shader_source[] = | |
| 366 "uniform mat4 u_mvpMatrix; \n" | |
| 367 "attribute vec4 a_position; \n" | |
| 368 "void main() \n" | |
| 369 "{ \n" | |
| 370 " gl_Position = u_mvpMatrix * a_position; \n" | |
| 371 "} \n"; | |
| 372 | |
| 373 const char fragment_shader_source[] = | |
| 374 "precision mediump float; \n" | |
| 375 "uniform vec4 u_color; \n" | |
| 376 "void main() \n" | |
| 377 "{ \n" | |
| 378 " gl_FragColor = u_color; \n" | |
| 379 "} \n"; | |
| 380 | |
| 381 state_->program_object_ = LoadProgram( | |
| 382 vertext_shader_source, fragment_shader_source); | |
| 383 state_->position_location_ = glGetAttribLocation( | |
| 384 state_->program_object_, "a_position"); | |
| 385 state_->mvp_location_ = glGetUniformLocation( | |
| 386 state_->program_object_, "u_mvpMatrix"); | |
| 387 state_->color_location_ = glGetUniformLocation( | |
| 388 state_->program_object_, "u_color"); | |
| 389 state_->num_indices_ = GenerateCube( | |
| 390 &state_->vbo_vertices_, &state_->vbo_indices_); | |
| 391 | |
| 392 glClearColor(0.0f, 0.0f, 0.0f, 0.0f); | |
| 393 initialized_ = true; | |
| 394 } | |
| 395 | |
| 396 void SpinningCube::OnGLContextLost() { | |
| 397 initialized_ = false; | |
| 398 height_ = 0; | |
| 399 width_ = 0; | |
| 400 state_->OnGLContextLost(); | |
| 401 } | |
| 402 | |
| 403 void SpinningCube::SetFlingMultiplier(float drag_distance, | |
| 404 float drag_time) { | |
| 405 fling_multiplier_ = RotationForDragDistance(drag_distance) / | |
| 406 RotationForTimeDelta(drag_time); | |
| 407 | |
| 408 } | |
| 409 | |
| 410 void SpinningCube::UpdateForTimeDelta(float delta_time) { | |
| 411 state_->angle_ += RotationForTimeDelta(delta_time) * fling_multiplier_; | |
| 412 if (state_->angle_ >= 360.0f) | |
| 413 state_->angle_ -= 360.0f; | |
| 414 | |
| 415 // Arbitrary 50-step linear reduction in spin speed. | |
| 416 if (fling_multiplier_ > 1.0f) { | |
| 417 fling_multiplier_ = | |
| 418 std::max(1.0f, fling_multiplier_ - (fling_multiplier_ - 1.0f) / 50); | |
| 419 } | |
| 420 | |
| 421 Update(); | |
| 422 } | |
| 423 | |
| 424 void SpinningCube::UpdateForDragDistance(float distance) { | |
| 425 state_->angle_ += RotationForDragDistance(distance); | |
| 426 if (state_->angle_ >= 360.0f ) | |
| 427 state_->angle_ -= 360.0f; | |
| 428 | |
| 429 Update(); | |
| 430 } | |
| 431 | |
| 432 void SpinningCube::Draw() { | |
| 433 glViewport(0, 0, width_, height_); | |
| 434 glClear(GL_COLOR_BUFFER_BIT); | |
| 435 glUseProgram(state_->program_object_); | |
| 436 glBindBuffer(GL_ARRAY_BUFFER, state_->vbo_vertices_); | |
| 437 glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, state_->vbo_indices_); | |
| 438 glVertexAttribPointer(state_->position_location_, | |
| 439 3, | |
| 440 GL_FLOAT, | |
| 441 GL_FALSE, 3 * sizeof(GLfloat), | |
| 442 0); | |
| 443 glEnableVertexAttribArray(state_->position_location_); | |
| 444 glUniformMatrix4fv(state_->mvp_location_, | |
| 445 1, | |
| 446 GL_FALSE, | |
| 447 (GLfloat*) &state_->mvp_matrix_.m[0][0]); | |
| 448 glUniform4f(state_->color_location_, color_[0], color_[1], color_[2], 1.0); | |
| 449 glDrawElements(GL_TRIANGLES, | |
| 450 state_->num_indices_, | |
| 451 GL_UNSIGNED_SHORT, | |
| 452 0); | |
| 453 } | |
| 454 | |
| 455 void SpinningCube::Update() { | |
| 456 float aspect = static_cast<GLfloat>(width_) / static_cast<GLfloat>(height_); | |
| 457 | |
| 458 ESMatrix perspective; | |
| 459 perspective.LoadIdentity(); | |
| 460 perspective.Perspective(60.0f, aspect, 1.0f, 20.0f ); | |
| 461 | |
| 462 ESMatrix modelview; | |
| 463 modelview.LoadIdentity(); | |
| 464 modelview.Translate(0.0, 0.0, -2.0); | |
| 465 modelview.Rotate(state_->angle_ * direction_, 1.0, 0.0, 1.0); | |
| 466 | |
| 467 state_->mvp_matrix_.Multiply(&modelview, &perspective); | |
| 468 } | |
| 469 | |
| 470 } // namespace examples | |
| OLD | NEW |
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Chromium Code Reviews
Issue 684543003:
Move //mojo/examples to //examples (Closed)
Base URL: https://github.com/domokit/mojo.git@master