computer-grafik-1/u06-2/main.c

322 lines
7.5 KiB
C

#include <stdio.h>
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include "vertexShader.c"
#include "fragmentShader.c"
#include "matrixMath.h"
#include "transformation.h"
#include "wavefrontobj.h"
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <stdbool.h>
#define RESTART 345678
GLuint program;
GLuint vao;
int numFaces = 0;
bool exitRequested = false;
GLFWwindow* window;
GLfloat aspectRatio = 1.0f;
double timeBetweenUpdates = 0.2f;
double timeSinceUpdate = 0.0f;
int framesSinceUpdate = 0;
GLfloat step = 0.0f;
const GLfloat pi = 3.14159f;
vec3 cameraPosition = {0.0f, 3.0f, 5.5f};
// input handler for camera movement
void handleInputs(double deltaTime) {
if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS) {
cameraPosition.z += deltaTime * 10;
}
if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS) {
cameraPosition.z -= deltaTime * 10;
}
if (glfwGetKey(window, GLFW_KEY_SPACE) == GLFW_PRESS) {
cameraPosition.y += deltaTime * 10;
}
if (glfwGetKey(window, GLFW_KEY_LEFT_SHIFT) == GLFW_PRESS) {
cameraPosition.y -= deltaTime * 10;
}
}
// input handler to quit with ESC
void keyboardHandler(GLFWwindow* window, int key, int scancode, int action, int mods) {
if (action == GLFW_PRESS) {
if (key == GLFW_KEY_ESCAPE) {
exitRequested = true;
}
}
}
void init(void) {
// create and compile vertex shader
const GLchar *vertexTextConst = vertexShader_glsl;
GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertexTextConst, &vertexShader_glsl_len);
glCompileShader(vertexShader);
GLint status;
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &status);
if (!status) {
printf("Error compiling vertex shader: ");
GLchar infoLog[1024];
glGetShaderInfoLog(vertexShader, 1024, NULL, infoLog);
printf("%s",infoLog);
}
vertexTextConst = NULL;
// create and compile fragment shader
const GLchar *fragmentTextConst = fragmentShader_glsl;
GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragmentTextConst, &fragmentShader_glsl_len);
glCompileShader(fragmentShader);
glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &status);
if (!status) {
printf("Error compiling fragment shader: ");
GLchar infoLog[1024];
glGetShaderInfoLog(fragmentShader, 1024, NULL, infoLog);
printf("%s",infoLog);
}
// create and link shader program
program = glCreateProgram();
glAttachShader(program, vertexShader);
glAttachShader(program, fragmentShader);
glLinkProgram(program);
glGetProgramiv(program, GL_LINK_STATUS, &status);
if (!status) {
printf("Error linking program: ");
GLchar infoLog[1024];
glGetProgramInfoLog(program, 1024, NULL, infoLog);
printf("%s",infoLog);
}
glValidateProgram(program);
glGetProgramiv(program, GL_VALIDATE_STATUS, &status);
if (!status) {
printf("Error validating program: ");
GLchar infoLog[1024];
glGetProgramInfoLog(program, 1024, NULL, infoLog);
printf("%s",infoLog);
}
// --------------- READ teapot.obj
ParsedObjFile teapot = readObjFile("../obj/teapot.obj");
numFaces = teapot.length;
// write teapot faces to buffer
GLuint triangleVertexBufferObject;
glGenBuffers(1, &triangleVertexBufferObject);
glBindBuffer(GL_ARRAY_BUFFER, triangleVertexBufferObject);
glBufferData(GL_ARRAY_BUFFER, teapot.length * sizeof(face), teapot.faces, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
// create vertex array object
glGenVertexArrays(1, &vao);
glBindVertexArray(vao);
glBindBuffer(GL_ARRAY_BUFFER, triangleVertexBufferObject);
// vertex positions
glVertexAttribPointer(
0,
3,
GL_FLOAT,
GL_FALSE,
sizeof(vertex),
0
);
glEnableVertexAttribArray(0);
// vertex normals
glVertexAttribPointer(
1,
3,
GL_FLOAT,
GL_FALSE,
sizeof(vertex),
(void*) sizeof(vec3)
);
glEnableVertexAttribArray(1);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
// ENABLE BACKFACE CULLING
glFrontFace(GL_CCW);
glEnable(GL_CULL_FACE);
// ENABLE DEPTH BUFFER
glEnable(GL_DEPTH_TEST);
glClearColor(0.1f, 0.1f, 0.3f, 1.0f);
}
void updateStats() {
printf("\rFPS: %.1f", framesSinceUpdate / timeSinceUpdate);
printf(" - Camera Position: [%f, %f, %f]", cameraPosition.x, cameraPosition.y, cameraPosition.z);
fflush(stdout);
}
void draw(void) {
// FPS Counter
framesSinceUpdate++;
double deltaTime = glfwGetTime();
timeSinceUpdate += deltaTime;
glfwSetTime(0.0f);
if (timeSinceUpdate >= timeBetweenUpdates) {
updateStats();
timeSinceUpdate = 0.0f;
framesSinceUpdate = 0;
}
// camera movement
handleInputs(deltaTime);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glUseProgram(program);
glBindVertexArray(vao);
// step for rotations
// counts up to 1.0 and then resets back to 0.0 forever
step += deltaTime / 5;
if (step > 1.0f) step -= 1.0f;
// step multiplied by pi * 2 for use in rotation and trig functions
GLfloat stepi = step * pi * 2;
// ------------- MODEL TRANSFORMATION ---------------------
// SCALE -> ROTATE -> TRANSLATE
mat4 modelTransformation;
identity(&modelTransformation);
rotateY(&modelTransformation, &modelTransformation, stepi);
// ------------- VIEWING TRANSFORMATION -------------------
vec3 origin = {0.0f, 0.0f, 0.0f};
vec3 up = {0.0f, 1.0f, 0.0f};
mat4 viewingTransformation;
lookAt(&viewingTransformation, &cameraPosition, &origin, &up);
// -------------- PROJECTION TRANSFORMATION ----------------
mat4 projectionTransformation;
GLfloat near = 0.1f;
GLfloat far = 10.0f;
perspectiveProjection(&projectionTransformation, near, far);
// -------------- NORMALISATION TRANSFORMATION -------------
mat4 normalisationTransformation;
GLfloat fovy = pi / 2;
normalisedDeviceCoordinatesFov(&normalisationTransformation, fovy, aspectRatio, near, far);
mat4 globalTransformation;
identity(&globalTransformation);
// V * P * N * M
// (right to left because it's more intuitive in my opinion)
multiply(&globalTransformation, &modelTransformation, &globalTransformation);
multiply(&globalTransformation, &viewingTransformation, &globalTransformation);
multiply(&globalTransformation, &projectionTransformation, &globalTransformation);
multiply(&globalTransformation, &normalisationTransformation, &globalTransformation);
// send transformation matrix to shader
glUniformMatrix4fv(glGetUniformLocation(program, "globalTransformation"), 1, GL_FALSE, (GLfloat*)&globalTransformation);
// draw!!1
glDrawArrays(GL_TRIANGLES, 0, numFaces * 3);
}
// change viewport size and adjust aspect ratio when changing window size
void framebuffer_size_callback(GLFWwindow *window, int width, int height) {
glViewport(0, 0, width, height);
aspectRatio = (float)width / height;
}
int main(void) {
// initialise window
glfwInit();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
window = glfwCreateWindow(700, 700, "Computergrafik 1", NULL, NULL);
if (!window) {
printf("Failed to create window\n");
glfwTerminate();
return -1;
}
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
glfwMakeContextCurrent(window);
// disable framerate cap
glfwSwapInterval(0);
// register keyboard event handler
glfwSetKeyCallback(window, keyboardHandler);
// initialise glew
glewInit();
printf("OpenGL version supported by this platform (%s):\n", glGetString(GL_VERSION));
init();
// exit when window should close or exit is requested (ESC)
while (!glfwWindowShouldClose(window) && !exitRequested) {
draw();
glfwSwapBuffers(window);
glfwPollEvents();
}
glfwTerminate();
return 0;
}