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 glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
153 float d = (float)glutGet(GLUT_ELAPSED_TIME) * 0.001f;
155 glm::vec3 lightPos = glm::vec3(sin(d) * 10, 0, cos(d) * 10);
156 glm::vec4 lightColor(1, 1, 1, 1);
158 glViewport(0, 0, WIDTH, HEIGHT);
159 drawPyramids(d, lightPos, lightColor);
160 drawLight(d, lightPos, lightColor);
161 drawTeapot(teapotCamera, false, d, lightPos, lightColor);
163 glClear(GL_DEPTH_BUFFER_BIT);
165 glViewport(0, 0, WIDTH / 4, HEIGHT / 4);
166 drawTeapot(teapotOrtho, false, d, lightPos, lightColor);
168 glViewport(WIDTH / 4, 0, WIDTH / 4, HEIGHT / 4);
169 drawTeapot(teapotOrtho, true, d, lightPos, lightColor);
171 glViewport(WIDTH / 4 * 2, 0, WIDTH / 4, HEIGHT / 4);
172 drawTeapot(teapotPerspStatic, false, d, lightPos, lightColor);
174 glViewport(WIDTH / 4 * 3, 0, WIDTH / 4, HEIGHT / 4);
175 drawTeapot(teapotPerspAnimated, false, d, lightPos, lightColor);
180 void attachShader(GLuint progId, const char* filePath, GLenum type) {
181 GLuint shader = glCreateShader(type);
184 fprintf(stderr, "error creating shader\n");
188 ifstream file(filePath);
190 buffer << file.rdbuf();
191 string str = buffer.str();
192 const char* contents = str.c_str();
194 glShaderSource(shader, 1, (const GLchar**)&contents, NULL);
195 glCompileShader(shader);
197 glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
200 glGetShaderInfoLog(shader, 1024, NULL, log);
201 fprintf(stderr, "error: %s\n", log);
204 glAttachShader(progId, shader);
207 GLuint compileShaders(char* vertexShader, char* fragmentShader) {
208 GLuint progId = glCreateProgram();
210 attachShader(progId, vertexShader, GL_VERTEX_SHADER);
211 attachShader(progId, fragmentShader, GL_FRAGMENT_SHADER);
213 glLinkProgram(progId);
215 glGetProgramiv(progId, GL_LINK_STATUS, &success);
218 glGetProgramInfoLog(progId, sizeof(log), NULL, log);
219 fprintf(stderr, "error linking: %s\n", log);
226 #define BUFFER_OFFSET(i) ((char *)NULL + (i))
228 GLuint setupBuffers(glm::vec3* vertices, glm::vec3* normals, GLuint progId) {
256 GLuint numVerts = 18;
259 glGenBuffers(1, &vbo);
262 glGenVertexArrays(1, &vao);
264 GLuint posId = glGetAttribLocation(progId, "vPosition");
265 GLuint colorId = glGetAttribLocation(progId, "vColor");
266 GLuint normalLoc = glGetAttribLocation(progId, "vNormal");
268 GLuint vertsLen = numVerts * 3 * sizeof(GLfloat);
269 GLuint colorsLen = numVerts * 4 * sizeof(GLfloat);
270 GLuint normalLen = numVerts * 3 * sizeof(GLfloat);
272 glBindBuffer(GL_ARRAY_BUFFER, vbo);
273 glBufferData(GL_ARRAY_BUFFER, vertsLen + colorsLen + normalLen, NULL, GL_STATIC_DRAW);
275 glBufferSubData(GL_ARRAY_BUFFER, 0, vertsLen, glm::value_ptr(vertices[0]));
276 glBufferSubData(GL_ARRAY_BUFFER, vertsLen, colorsLen, colors);
277 glBufferSubData(GL_ARRAY_BUFFER, vertsLen + colorsLen, normalLen, glm::value_ptr(normals[0]));
279 glBindVertexArray(vao);
281 glEnableVertexAttribArray(posId);
282 glVertexAttribPointer(posId, 3, GL_FLOAT, GL_FALSE, 0, 0);
284 glEnableVertexAttribArray(colorId);
285 glVertexAttribPointer(colorId, 4, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(vertsLen));
287 glEnableVertexAttribArray(normalLoc);
288 glVertexAttribPointer(normalLoc, 3, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(vertsLen + colorsLen));
293 vector<glm::vec3> quadToTriangles(glm::vec3 *quads) {
294 vector<glm::vec3> triangles(6);
295 triangles[0] = quads[0];
296 triangles[1] = quads[1];
297 triangles[2] = quads[2];
298 triangles[3] = quads[2];
299 triangles[4] = quads[3];
300 triangles[5] = quads[0];
304 template <typename T>
305 void append(vector<T> &a, vector<T> &b) {
306 a.insert(a.end(), b.begin(), b.end());
309 void setupLightBuffers(GLuint progId) {
310 vector<glm::vec3> vertices;
311 glm::vec3 front[] = {
312 glm::vec3(1, -1, -1),
313 glm::vec3(-1, -1, -1),
314 glm::vec3(-1, 1, -1),
317 vector<glm::vec3> frontTriangles = quadToTriangles(front);
318 append(vertices, frontTriangles);
323 glm::vec3(-1, -1, 1),
326 vector<glm::vec3> backQuads = quadToTriangles(back);
327 append(vertices, backQuads);
331 glm::vec3(-1, 1, -1),
335 vector<glm::vec3> topTriangles = quadToTriangles(top);
336 append(vertices, topTriangles);
338 glm::vec3 bottom[] = {
340 glm::vec3(-1, -1, 1),
341 glm::vec3(-1, -1, -1),
344 vector<glm::vec3> bottomTriangles = quadToTriangles(bottom);
345 append(vertices, bottomTriangles);
349 glm::vec3(-1, 1, -1),
350 glm::vec3(-1, -1, -1),
353 vector<glm::vec3> leftTriangles = quadToTriangles(left);
354 append(vertices, leftTriangles);
356 glm::vec3 right[] = {
362 vector<glm::vec3> rightTriangles = quadToTriangles(right);
363 append(vertices, rightTriangles);
364 GLuint verticesSize = 36 * 3 * sizeof(GLfloat);
366 glGenVertexArrays(1, &lightVao);
368 glBindVertexArray(lightVao);
369 glGenBuffers(1, &vbo);
370 glBindBuffer(GL_ARRAY_BUFFER, vbo);
371 glBufferData(GL_ARRAY_BUFFER, verticesSize, NULL, GL_STATIC_DRAW);
372 glBufferSubData(GL_ARRAY_BUFFER, 0, verticesSize, glm::value_ptr(vertices[0]));
373 GLuint posLoc = glGetAttribLocation(progId, "vPosition");
374 glEnableVertexAttribArray(posLoc);
375 glVertexAttribPointer(posLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
378 void setupTeapotBuffers(GLuint progId) {
380 glGenBuffers(2, vbos);
381 glBindBuffer(GL_ARRAY_BUFFER, vbos[0]);
382 glBufferData(GL_ARRAY_BUFFER, 3 * teapot_vertex_count * sizeof(float), teapot_vertex_points, GL_STATIC_DRAW);
383 glBindBuffer(GL_ARRAY_BUFFER, vbos[1]);
384 glBufferData(GL_ARRAY_BUFFER, 3 * teapot_vertex_count * sizeof(float), teapot_normals, GL_STATIC_DRAW);
386 glGenVertexArrays(1, &teapotVao);
387 glBindVertexArray(teapotVao);
389 GLuint posLoc = glGetAttribLocation(progId, "vPosition");
390 GLuint normalLoc = glGetAttribLocation(progId, "vNormal");
392 glEnableVertexAttribArray(posLoc);
393 glBindBuffer(GL_ARRAY_BUFFER, vbos[0]);
394 glVertexAttribPointer(posLoc, 3, GL_FLOAT, GL_FALSE, 0, NULL);
396 glEnableVertexAttribArray(normalLoc);
397 glBindBuffer(GL_ARRAY_BUFFER, vbos[1]);
398 glVertexAttribPointer(normalLoc, 3, GL_FLOAT, GL_FALSE, 0, NULL);
401 void validateProgram(GLuint progId) {
402 glValidateProgram(progId);
405 glGetProgramiv(progId, GL_VALIDATE_STATUS, &success);
408 glGetProgramInfoLog(progId, sizeof(log), NULL, log);
409 fprintf(stderr, "error: %s\n", log);
415 glm::vec3 vertices[18] = {
416 glm::vec3(0.0f, 1.0f, 0.0f),
417 glm::vec3(1.0f, -1.0f, -1.0f),
418 glm::vec3(-1.0f, -1.0f, -1.0f),
420 glm::vec3(0.0f, 1.0f, 0.0f),
421 glm::vec3(-1.0f, -1.0f, 1.0f),
422 glm::vec3(1.0f, -1.0f, 1.0f),
424 glm::vec3(0.0f, 1.0f, 0.0f),
425 glm::vec3(-1.0f, -1.0f, -1.0f),
426 glm::vec3(-1.0f, -1.0f, 1.0f),
428 glm::vec3(0.0f, 1.0f, 0.0f),
429 glm::vec3(1.0f, -1.0f, 1.0f),
430 glm::vec3(1.0f, -1.0f, -1.0f),
433 glm::vec3(-1, -1, 1),
434 glm::vec3(-1, -1, -1),
435 glm::vec3(-1, -1, -1),
436 glm::vec3(1, -1, -1),
440 // work out the normals
441 glm::vec3 normals[18];
442 for (int i = 0; i < 6; i++) {
443 glm::vec3 a = vertices[i * 3];
444 glm::vec3 b = vertices[i * 3 + 1];
445 glm::vec3 c = vertices[i * 3 + 2];
446 glm::vec3 u = glm::normalize(a - c);
447 glm::vec3 v = glm::normalize(b - c);
448 glm::vec3 norm = glm::normalize(glm::cross(v, u));
449 for(int j = 0; j < 3; j++) {
450 normals[i * 3 + j] = -glm::vec3(norm);
454 gradientProgId = compileShaders((char*)"vertex.glsl", (char*)"fragment.glsl");
455 glUseProgram(gradientProgId);
456 pyramidVao = setupBuffers(vertices, normals, gradientProgId);
457 validateProgram(gradientProgId);
459 solidProgId = compileShaders((char*)"solidvertex.glsl", (char*)"solidfrag.glsl");
460 glUseProgram(solidProgId);
461 setupLightBuffers(solidProgId);
462 validateProgram(solidProgId);
464 normalProgId = compileShaders((char*)"vertex.glsl", (char*)"normalfrag.glsl");
465 glUseProgram(normalProgId);
466 setupTeapotBuffers(normalProgId);
467 validateProgram(normalProgId);
469 glEnable(GL_DEPTH_TEST);
470 glEnable(GL_CULL_FACE);
473 bool* keyStates = new bool[256];
475 void keyboard(unsigned char key, int x, int y) {
476 keyStates[key] = true;
480 doRotate = !doRotate;
482 doTranslate = !doTranslate;
485 void keyboardUp(unsigned char key, int x, int y) {
486 keyStates[key] = false;
490 float xSpeed = 0.f, ySpeed = 0.f, zSpeed = 0.f;
504 camPos.x += xSpeed * sin(yaw) + zSpeed * cos(yaw);
506 camPos.z += zSpeed * sin(yaw) - xSpeed * cos(yaw);
508 glutTimerFunc(16, timer, 0);
511 int prevMouseX, prevMouseY;
512 bool firstMouse = true;
514 void motion(int x, int y) {
520 int dx = x - prevMouseX, dy = y - prevMouseY;
525 const float sensitivity = 0.005f;
526 yaw += dx * sensitivity;
527 pitch -= dy * sensitivity;
530 front.x = cos(pitch) * cos(yaw);
531 front.y = sin(pitch);
532 front.z = cos(pitch) * sin(yaw);
533 camFront = glm::normalize(front);
536 void mouse(int button, int state, int x, int y) {
537 if (button == GLUT_LEFT_BUTTON && state == GLUT_UP)
541 int main(int argc, char** argv) {
542 glutInit(&argc, argv);
543 glutInitDisplayMode(GLUT_DEPTH|GLUT_DOUBLE|GLUT_RGB|GLUT_3_2_CORE_PROFILE);
544 glutInitWindowSize(WIDTH, HEIGHT);
545 int win = glutCreateWindow("Hello Triangle");
546 glutDisplayFunc(display);
552 glutKeyboardFunc(keyboard);
553 glutKeyboardUpFunc(keyboardUp);
554 glutTimerFunc(16, timer, 0);
555 glutMotionFunc(motion);
556 glutMouseFunc(mouse);