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u03-1

This commit is contained in:
Luca Conte 2024-03-25 13:27:22 +01:00
parent 489a444f8e
commit 986c37de80
2 changed files with 293 additions and 0 deletions
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5
u03-1/Makefile Normal file
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GLEW_LIBS=$(shell pkgconf glew --libs)
GLFW_LIBS=$(shell pkgconf glfw3 --libs)
cg1: main.c
gcc -o cg1.out main.c $(GLEW_LIBS) $(GLFW_LIBS)

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u03-1/main.c Normal file
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#include <stdio.h>
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <math.h>
GLuint program;
GLuint vao;
GLfloat offsetX = -0.75f;
GLfloat offsetY = 0.4f;
GLfloat speedX = 0.0005f;
GLfloat speedY = -0.0005f;
#define NUM_TRIANGLES 8
typedef struct {
GLfloat x;
GLfloat y;
} Point;
typedef struct {
GLfloat r;
GLfloat g;
GLfloat b;
} Color;
typedef struct {
Point p1;
Point p2;
Point p3;
} Triangle;
typedef struct {
Triangle t1;
Triangle t2;
} TriangleRect;
void hueToRgb(GLfloat hue, GLfloat* r, GLfloat* g, GLfloat* b) {
GLfloat x = hue / 60;
while (x > 2) x -= 2;
x = x - 1;
x = 1 - fabs(x);
if (hue < 60) {
*r = 1.0f;
*g = x;
*b = 0;
} else if (hue < 120) {
*r = x;
*g = 1.0f;
*b = 0;
} else if (hue < 180) {
*r = 0;
*g = 1.0f;
*b = x;
} else if (hue < 240) {
*r = 0;
*g = x;
*b = 1.0f;
} else if (hue < 300) {
*r = x;
*g = 0;
*b = 1.0f;
} else {
*r = 1.0f;
*g = 0;
*b = x;
}
}
void createRect(TriangleRect* rect, GLfloat posx, GLfloat posy, GLfloat width, GLfloat height) {
rect->t1.p1.x = posx;
rect->t1.p1.y = posy;
rect->t1.p2.x = posx + width;
rect->t1.p2.y = posy;
rect->t1.p3.x = posx;
rect->t1.p3.y = posy + height;
rect->t2.p1.x = posx + width;
rect->t2.p1.y = posy;
rect->t2.p2.x = posx + width;
rect->t2.p2.y = posy + height;
rect->t2.p3.x = posx;
rect->t2.p3.y = posy + height;
}
void createCenterRect(TriangleRect* rect, GLfloat posx, GLfloat posy, GLfloat width, GLfloat height) {
createRect(rect, posx - width / 2, posy - height / 2, width, height);
}
void init(void) {
// create and compile vertex shader
const char *vertexText =
"#version 330 core\n"
"layout (location = 0) in vec2 aPosition;\n"
"layout (location = 1) in vec3 aColor;\n"
// "uniform vec3 color;\n"
"uniform vec2 offset;"
"out vec3 vertexColor;\n"
"void main() {\n"
" gl_Position = vec4(aPosition + offset, 0.0, 1.0);\n"
" vertexColor = aColor;"
"}\n";
GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertexText, NULL);
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);
}
// create and compile fragment shader
const char *fragmentText =
"#version 330 core\n"
"in vec3 vertexColor;\n"
"void main() {\n"
" gl_FragColor = vec4(vertexColor, 1.0);\n"
"}\n";
GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragmentText, NULL);
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);
}
TriangleRect triangleVertices[4];
createCenterRect(&triangleVertices[0], -0.2f, 0.0f, 0.1f, 1.2f);
createCenterRect(&triangleVertices[1], 0.2f, 0.0f, 0.1f, 1.2f);
createCenterRect(&triangleVertices[2], 0.0f, 0.0f, 0.3f, 0.1f);
createCenterRect(&triangleVertices[3], 0.0f, -0.8f, 0.5f, 0.1f);
Color colors[24];
for (int i = 0; i < 48; i++) {
hueToRgb(i * 15.0f, &colors[i].r, &colors[i].g, &colors[i].b);
}
GLuint triangleVertexBufferObject;
glGenBuffers(1, &triangleVertexBufferObject);
glBindBuffer(GL_ARRAY_BUFFER, triangleVertexBufferObject);
glBufferData(GL_ARRAY_BUFFER, sizeof(triangleVertices), triangleVertices, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
// CREATE COLOR BUFFER
GLuint colorBufferObject;
glGenBuffers(1, &colorBufferObject);
glBindBuffer(GL_ARRAY_BUFFER, colorBufferObject);
glBufferData(GL_ARRAY_BUFFER, sizeof(colors), colors, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
// create vertex array object
glGenVertexArrays(1, &vao);
glBindVertexArray(vao);
glBindBuffer(GL_ARRAY_BUFFER, triangleVertexBufferObject);
glVertexAttribPointer(
0,
2,
GL_FLOAT,
GL_FALSE,
sizeof(Point),
0
);
glEnableVertexAttribArray(0);
glBindBuffer(GL_ARRAY_BUFFER, colorBufferObject);
glVertexAttribPointer(
1,
3,
GL_FLOAT,
GL_FALSE,
0,
0
);
glEnableVertexAttribArray(1);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
}
void draw(void) {
glClear(GL_COLOR_BUFFER_BIT);
glUseProgram(program);
glBindVertexArray(vao);
offsetX += speedX;
offsetY += speedY;
if (offsetX >= 0.75f || offsetX <= -0.75f) speedX *= -1;
if (offsetY >= 0.4f || offsetY <=-0.15f) speedY *= -1;
// SET COLOR
glUniform2f(glGetUniformLocation(program, "offset"), offsetX, offsetY);
glDrawArrays(GL_TRIANGLES, 0, NUM_TRIANGLES * 3);
}
void framebuffer_size_callback(GLFWwindow *window, int width, int height) {
glViewport(0, 0, width, height);
}
int main(void) {
printf("Hello World!\n");
glfwInit();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
GLFWwindow *window = glfwCreateWindow(800, 600, "Computergrafik 1", NULL, NULL);
if (!window) {
printf("Failed to create window\n");
glfwTerminate();
return -1;
}
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
glfwMakeContextCurrent(window);
glewInit();
init();
while (!glfwWindowShouldClose(window)) {
draw();
glfwSwapBuffers(window);
glfwPollEvents();
}
glfwTerminate();
return 0;
}