11 #include <OpenGL/glew.h>
13 #include <GLUT/glut.h>
14 #include <glm/glm.hpp>
15 #include <glm/ext.hpp>
16 #include <glm/gtc/type_ptr.hpp>
19 #pragma clang diagnostic ignored "-Wdeprecated-declarations"
23 GLuint pyramidVao, lightVao, teapotVao;
24 GLuint gradientProgId, solidProgId, normalProgId;
25 glm::vec3 camPos = glm::vec3(0.0f, 0.0f, -10.0f);
26 glm::vec3 camFront = glm::vec3(0.0f, 0.0f, 1.0f);
27 glm::vec3 camUp = glm::vec3(0.0f, 1.0f, 0.0f);
28 float yaw = 1.57, pitch = 0;
29 bool doScale, doRotate, doTranslate;
31 const int WIDTH = 800, HEIGHT = 600;
32 const float ASPECT = (float)WIDTH / (float)HEIGHT;
34 void setProjectionAndViewUniforms(GLuint progId) {
35 GLuint projId = glGetUniformLocation(progId, "projection");
36 glm::mat4 proj = glm::perspective(glm::radians(45.f), ASPECT, 0.01f, 10000.f);
37 glUniformMatrix4fv(projId, 1, GL_FALSE, glm::value_ptr(proj));
39 GLuint viewId = glGetUniformLocation(progId, "view");
40 glm::mat4 view = glm::lookAt(camPos, camPos + camFront, camUp);
41 glUniformMatrix4fv(viewId, 1, GL_FALSE, glm::value_ptr(view));
44 void setLightColorAndPos(GLuint progId, glm::vec3 lightPos, glm::vec4 lightColor) {
45 GLuint lightColorLoc = glGetUniformLocation(progId, "lightColor");
46 glUniform4fv(lightColorLoc, 1, glm::value_ptr(lightColor));
48 GLuint lightPosLoc = glGetUniformLocation(progId, "lightPos");
49 glUniform3fv(lightPosLoc, 1, glm::value_ptr(lightPos));
52 void drawLight(float d, glm::vec3 lightPos, glm::vec4 lightColor) {
53 glUseProgram(solidProgId);
54 glBindVertexArray(lightVao);
55 setProjectionAndViewUniforms(solidProgId);
56 glm::mat4 model = glm::translate(glm::mat4(1.f), lightPos);
57 model = glm::scale(model, glm::vec3(0.2));
58 GLuint modelId = glGetUniformLocation(solidProgId, "model");
59 glUniformMatrix4fv(modelId, 1, GL_FALSE, glm::value_ptr(model));
61 GLuint colorLoc = glGetUniformLocation(solidProgId, "color");
62 glm::vec4 color(lightColor);
63 glUniform4fv(colorLoc, 1, glm::value_ptr(color));
65 glDrawArrays(GL_TRIANGLES, 0, 36);
68 void drawPyramids(float d, glm::vec3 lightPos, glm::vec4 lightColor) {
69 glUseProgram(gradientProgId);
70 glBindVertexArray(pyramidVao);
71 setProjectionAndViewUniforms(gradientProgId);
73 setLightColorAndPos(gradientProgId, lightPos, lightColor);
75 GLuint viewPosLoc = glGetUniformLocation(gradientProgId, "viewPos");
76 glUniform3fv(viewPosLoc, 1, glm::value_ptr(camPos));
78 GLuint modelId = glGetUniformLocation(gradientProgId, "model");
80 for (int i = 0; i < 10; i++) {
82 glm::mat4 model = glm::mat4(1.f);
84 model = glm::translate(model, glm::vec3(sin(i * 30) * 10, 0, i * 2 - 10));
87 model = glm::rotate(model, d * glm::radians(30.f), glm::vec3(0.f, 1.f, 0.f));
88 model = glm::rotate(model, d * glm::radians(20.f), glm::vec3(1.f, 0.f, 0.f));
92 model = glm::scale(model, glm::vec3(1.f, 0.7f + 0.7f * (1 + sin(d + (i + 3))), 1.f));
95 model = glm::translate(model, glm::vec3(sin(d + (i + 1)), cos(d + (i + -3)), sin(d + (i + 4))));
98 glUniformMatrix4fv(modelId, 1, GL_FALSE, glm::value_ptr(model));
100 glDrawArrays(GL_TRIANGLES, 0, 18);
105 enum TeapotProjection { teapotOrtho, teapotCamera, teapotPerspStatic, teapotPerspAnimated };
107 void drawTeapot(TeapotProjection proj, bool rotate, float d, glm::vec3 lightPos, glm::vec4 lightColor) {
108 glUseProgram(normalProgId);
110 GLuint projId = glGetUniformLocation(normalProgId, "projection");
111 GLuint viewId = glGetUniformLocation(normalProgId, "view");
114 setProjectionAndViewUniforms(normalProgId);
118 glm::mat4 proj = glm::ortho(-5.f * ASPECT, 5.f * ASPECT, -5.f, 5.f, 0.01f, 1000.f);
119 glUniformMatrix4fv(projId, 1, GL_FALSE, glm::value_ptr(proj));
121 glm::vec3 camPos(-5, 5, -5), camFront = glm::vec3(0) - camPos;
122 glm::mat4 view = glm::lookAt(camPos, camPos + camFront, camUp);
123 glUniformMatrix4fv(viewId, 1, GL_FALSE, glm::value_ptr(view));
126 case teapotPerspStatic:
127 case teapotPerspAnimated:
129 float fov = glm::radians(45.f);
130 if (proj == teapotPerspAnimated)
131 fov += glm::radians(sin(d) * 30.f);
132 glm::mat4 proj = glm::perspective(fov, ASPECT, 0.01f, 10000.f);
133 glUniformMatrix4fv(projId, 1, GL_FALSE, glm::value_ptr(proj));
135 glm::mat4 view = glm::lookAt(glm::vec3(0, 0, -10), glm::vec3(0), camUp);
136 glUniformMatrix4fv(viewId, 1, GL_FALSE, glm::value_ptr(view));
140 setLightColorAndPos(normalProgId, lightPos, lightColor);
141 glBindVertexArray(teapotVao);
142 GLuint modelId = glGetUniformLocation(normalProgId, "model");
144 model = glm::scale(model, glm::vec3(0.3));
145 if (rotate) model = glm::rotate(model, d, glm::vec3(0, 1, 0));
146 glUniformMatrix4fv(modelId, 1, GL_FALSE, glm::value_ptr(model));
148 glDrawArrays(GL_TRIANGLES, 0, teapot_vertex_count);
152 glClearColor(0.5, 0.5, 0.5, 1);
153 glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
154 float d = (float)glutGet(GLUT_ELAPSED_TIME) * 0.001f;
156 glm::vec3 lightPos = glm::vec3(sin(d) * 10, 0, cos(d) * 10);
157 glm::vec4 lightColor(1, 1, 1, 1);
159 glViewport(0, 0, WIDTH, HEIGHT);
160 drawPyramids(d, lightPos, lightColor);
161 drawLight(d, lightPos, lightColor);
162 drawTeapot(teapotCamera, false, d, lightPos, lightColor);
164 glClear(GL_DEPTH_BUFFER_BIT);
166 glViewport(0, 0, WIDTH / 4, HEIGHT / 4);
167 drawTeapot(teapotOrtho, false, d, lightPos, lightColor);
169 glViewport(WIDTH / 4, 0, WIDTH / 4, HEIGHT / 4);
170 drawTeapot(teapotOrtho, true, d, lightPos, lightColor);
172 glViewport(WIDTH / 4 * 2, 0, WIDTH / 4, HEIGHT / 4);
173 drawTeapot(teapotPerspStatic, false, d, lightPos, lightColor);
175 glViewport(WIDTH / 4 * 3, 0, WIDTH / 4, HEIGHT / 4);
176 drawTeapot(teapotPerspAnimated, false, d, lightPos, lightColor);
181 void attachShader(GLuint progId, const char* filePath, GLenum type) {
182 GLuint shader = glCreateShader(type);
185 fprintf(stderr, "error creating shader\n");
189 ifstream file(filePath);
191 buffer << file.rdbuf();
192 string str = buffer.str();
193 const char* contents = str.c_str();
195 glShaderSource(shader, 1, (const GLchar**)&contents, NULL);
196 glCompileShader(shader);
198 glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
201 glGetShaderInfoLog(shader, 1024, NULL, log);
202 fprintf(stderr, "error: %s\n", log);
205 glAttachShader(progId, shader);
208 GLuint compileShaders(char* vertexShader, char* fragmentShader) {
209 GLuint progId = glCreateProgram();
211 attachShader(progId, vertexShader, GL_VERTEX_SHADER);
212 attachShader(progId, fragmentShader, GL_FRAGMENT_SHADER);
214 glLinkProgram(progId);
216 glGetProgramiv(progId, GL_LINK_STATUS, &success);
219 glGetProgramInfoLog(progId, sizeof(log), NULL, log);
220 fprintf(stderr, "error linking: %s\n", log);
227 #define BUFFER_OFFSET(i) ((char *)NULL + (i))
229 GLuint setupBuffers(glm::vec3* vertices, glm::vec3* normals, GLuint progId) {
257 GLuint numVerts = 18;
260 glGenBuffers(1, &vbo);
263 glGenVertexArrays(1, &vao);
265 GLuint posId = glGetAttribLocation(progId, "vPosition");
266 GLuint colorId = glGetAttribLocation(progId, "vColor");
267 GLuint normalLoc = glGetAttribLocation(progId, "vNormal");
269 GLuint vertsLen = numVerts * 3 * sizeof(GLfloat);
270 GLuint colorsLen = numVerts * 4 * sizeof(GLfloat);
271 GLuint normalLen = numVerts * 3 * sizeof(GLfloat);
273 glBindBuffer(GL_ARRAY_BUFFER, vbo);
274 glBufferData(GL_ARRAY_BUFFER, vertsLen + colorsLen + normalLen, NULL, GL_STATIC_DRAW);
276 glBufferSubData(GL_ARRAY_BUFFER, 0, vertsLen, glm::value_ptr(vertices[0]));
277 glBufferSubData(GL_ARRAY_BUFFER, vertsLen, colorsLen, colors);
278 glBufferSubData(GL_ARRAY_BUFFER, vertsLen + colorsLen, normalLen, glm::value_ptr(normals[0]));
280 glBindVertexArray(vao);
282 glEnableVertexAttribArray(posId);
283 glVertexAttribPointer(posId, 3, GL_FLOAT, GL_FALSE, 0, 0);
285 glEnableVertexAttribArray(colorId);
286 glVertexAttribPointer(colorId, 4, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(vertsLen));
288 glEnableVertexAttribArray(normalLoc);
289 glVertexAttribPointer(normalLoc, 3, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(vertsLen + colorsLen));
294 vector<glm::vec3> quadToTriangles(glm::vec3 *quads) {
295 vector<glm::vec3> triangles(6);
296 triangles[0] = quads[0];
297 triangles[1] = quads[1];
298 triangles[2] = quads[2];
299 triangles[3] = quads[2];
300 triangles[4] = quads[3];
301 triangles[5] = quads[0];
305 template <typename T>
306 void append(vector<T> &a, vector<T> &b) {
307 a.insert(a.end(), b.begin(), b.end());
310 void setupLightBuffers(GLuint progId) {
311 vector<glm::vec3> vertices;
312 glm::vec3 front[] = {
313 glm::vec3(1, -1, -1),
314 glm::vec3(-1, -1, -1),
315 glm::vec3(-1, 1, -1),
318 vector<glm::vec3> frontTriangles = quadToTriangles(front);
319 append(vertices, frontTriangles);
324 glm::vec3(-1, -1, 1),
327 vector<glm::vec3> backQuads = quadToTriangles(back);
328 append(vertices, backQuads);
332 glm::vec3(-1, 1, -1),
336 vector<glm::vec3> topTriangles = quadToTriangles(top);
337 append(vertices, topTriangles);
339 glm::vec3 bottom[] = {
341 glm::vec3(-1, -1, 1),
342 glm::vec3(-1, -1, -1),
345 vector<glm::vec3> bottomTriangles = quadToTriangles(bottom);
346 append(vertices, bottomTriangles);
350 glm::vec3(-1, 1, -1),
351 glm::vec3(-1, -1, -1),
354 vector<glm::vec3> leftTriangles = quadToTriangles(left);
355 append(vertices, leftTriangles);
357 glm::vec3 right[] = {
363 vector<glm::vec3> rightTriangles = quadToTriangles(right);
364 append(vertices, rightTriangles);
365 GLuint verticesSize = 36 * 3 * sizeof(GLfloat);
367 glGenVertexArrays(1, &lightVao);
369 glBindVertexArray(lightVao);
370 glGenBuffers(1, &vbo);
371 glBindBuffer(GL_ARRAY_BUFFER, vbo);
372 glBufferData(GL_ARRAY_BUFFER, verticesSize, NULL, GL_STATIC_DRAW);
373 glBufferSubData(GL_ARRAY_BUFFER, 0, verticesSize, glm::value_ptr(vertices[0]));
374 GLuint posLoc = glGetAttribLocation(progId, "vPosition");
375 glEnableVertexAttribArray(posLoc);
376 glVertexAttribPointer(posLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
379 void setupTeapotBuffers(GLuint progId) {
381 glGenBuffers(2, vbos);
382 glBindBuffer(GL_ARRAY_BUFFER, vbos[0]);
383 glBufferData(GL_ARRAY_BUFFER, 3 * teapot_vertex_count * sizeof(float), teapot_vertex_points, GL_STATIC_DRAW);
384 glBindBuffer(GL_ARRAY_BUFFER, vbos[1]);
385 glBufferData(GL_ARRAY_BUFFER, 3 * teapot_vertex_count * sizeof(float), teapot_normals, GL_STATIC_DRAW);
387 glGenVertexArrays(1, &teapotVao);
388 glBindVertexArray(teapotVao);
390 GLuint posLoc = glGetAttribLocation(progId, "vPosition");
391 GLuint normalLoc = glGetAttribLocation(progId, "vNormal");
393 glEnableVertexAttribArray(posLoc);
394 glBindBuffer(GL_ARRAY_BUFFER, vbos[0]);
395 glVertexAttribPointer(posLoc, 3, GL_FLOAT, GL_FALSE, 0, NULL);
397 glEnableVertexAttribArray(normalLoc);
398 glBindBuffer(GL_ARRAY_BUFFER, vbos[1]);
399 glVertexAttribPointer(normalLoc, 3, GL_FLOAT, GL_FALSE, 0, NULL);
402 void validateProgram(GLuint progId) {
403 glValidateProgram(progId);
406 glGetProgramiv(progId, GL_VALIDATE_STATUS, &success);
409 glGetProgramInfoLog(progId, sizeof(log), NULL, log);
410 fprintf(stderr, "error: %s\n", log);
416 glm::vec3 vertices[18] = {
417 glm::vec3(0.0f, 1.0f, 0.0f),
418 glm::vec3(1.0f, -1.0f, -1.0f),
419 glm::vec3(-1.0f, -1.0f, -1.0f),
421 glm::vec3(0.0f, 1.0f, 0.0f),
422 glm::vec3(-1.0f, -1.0f, 1.0f),
423 glm::vec3(1.0f, -1.0f, 1.0f),
425 glm::vec3(0.0f, 1.0f, 0.0f),
426 glm::vec3(-1.0f, -1.0f, -1.0f),
427 glm::vec3(-1.0f, -1.0f, 1.0f),
429 glm::vec3(0.0f, 1.0f, 0.0f),
430 glm::vec3(1.0f, -1.0f, 1.0f),
431 glm::vec3(1.0f, -1.0f, -1.0f),
434 glm::vec3(-1, -1, 1),
435 glm::vec3(-1, -1, -1),
436 glm::vec3(-1, -1, -1),
437 glm::vec3(1, -1, -1),
441 // work out the normals
442 glm::vec3 normals[18];
443 for (int i = 0; i < 6; i++) {
444 glm::vec3 a = vertices[i * 3];
445 glm::vec3 b = vertices[i * 3 + 1];
446 glm::vec3 c = vertices[i * 3 + 2];
447 glm::vec3 u = glm::normalize(a - c);
448 glm::vec3 v = glm::normalize(b - c);
449 glm::vec3 norm = glm::normalize(glm::cross(v, u));
450 for(int j = 0; j < 3; j++) {
451 normals[i * 3 + j] = -glm::vec3(norm);
455 gradientProgId = compileShaders((char*)"vertex.glsl", (char*)"fragment.glsl");
456 glUseProgram(gradientProgId);
457 pyramidVao = setupBuffers(vertices, normals, gradientProgId);
458 validateProgram(gradientProgId);
460 solidProgId = compileShaders((char*)"solidvertex.glsl", (char*)"solidfrag.glsl");
461 glUseProgram(solidProgId);
462 setupLightBuffers(solidProgId);
463 validateProgram(solidProgId);
465 normalProgId = compileShaders((char*)"vertex.glsl", (char*)"normalfrag.glsl");
466 glUseProgram(normalProgId);
467 setupTeapotBuffers(normalProgId);
468 validateProgram(normalProgId);
470 glEnable(GL_DEPTH_TEST);
471 glEnable(GL_CULL_FACE);
474 bool* keyStates = new bool[256];
476 void keyboard(unsigned char key, int x, int y) {
477 keyStates[key] = true;
481 doRotate = !doRotate;
483 doTranslate = !doTranslate;
486 void keyboardUp(unsigned char key, int x, int y) {
487 keyStates[key] = false;
491 float xSpeed = 0.f, ySpeed = 0.f, zSpeed = 0.f;
505 camPos.x += xSpeed * sin(yaw) + zSpeed * cos(yaw);
507 camPos.z += zSpeed * sin(yaw) - xSpeed * cos(yaw);
509 glutTimerFunc(16, timer, 0);
512 int prevMouseX, prevMouseY;
513 bool firstMouse = true;
515 void motion(int x, int y) {
521 int dx = x - prevMouseX, dy = y - prevMouseY;
526 const float sensitivity = 0.005f;
527 yaw += dx * sensitivity;
528 pitch -= dy * sensitivity;
531 front.x = cos(pitch) * cos(yaw);
532 front.y = sin(pitch);
533 front.z = cos(pitch) * sin(yaw);
534 camFront = glm::normalize(front);
536 if (pitch < -1.57079632679 || pitch >= 1.57079632679) {
537 camUp = glm::vec3(0, -1, 0);
539 camUp = glm::vec3(0, 1, 0);
543 void mouse(int button, int state, int x, int y) {
544 if (button == GLUT_LEFT_BUTTON && state == GLUT_UP)
548 int main(int argc, char** argv) {
549 glutInit(&argc, argv);
550 glutInitDisplayMode(GLUT_DEPTH|GLUT_DOUBLE|GLUT_RGB|GLUT_3_2_CORE_PROFILE);
551 glutInitWindowSize(WIDTH, HEIGHT);
552 int win = glutCreateWindow("Hello Triangle");
553 glutDisplayFunc(display);
559 glutKeyboardFunc(keyboard);
560 glutKeyboardUpFunc(keyboardUp);
561 glutTimerFunc(16, timer, 0);
562 glutMotionFunc(motion);
563 glutMouseFunc(mouse);