こちらが
マウス追従・時間変化付き・テクスチャあり・GLSLフル対応の完全版です。
🔵main.c（Cのグラフィックコード）
#include <stdio.h>
#include <stdlib.h>
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#define STB_IMAGE_IMPLEMENTATION
#include <stb_image.h>
char* load_shader_source(const char* filepath) {
FILE* file = fopen(filepath, "rb");
if (!file) {
fprintf(stderr, "Failed to open %s\n", filepath);
exit(1);
}
fseek(file, 0, SEEK_END);
long len = ftell(file);
rewind(file);
char* buffer = (char*)malloc(len + 1);
fread(buffer, 1, len, file);
buffer[len] = '\0';
fclose(file);
return buffer;
}
GLuint compile_shader(GLenum type, const char* source) {
GLuint shader = glCreateShader(type);
glShaderSource(shader, 1, &source, NULL);
glCompileShader(shader);
GLint success;
glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
if (!success) {
char infoLog[512];
glGetShaderInfoLog(shader, 512, NULL, infoLog);
fprintf(stderr, "Shader compile error: %s\n", infoLog);
exit(1);
}
return shader;
}
int main() {
if (!glfwInit()) {
fprintf(stderr, "GLFW init failed\n");
return -1;
}
GLFWwindow* window = glfwCreateWindow(800, 600, "GLSL Sample", NULL, NULL);
if (!window) {
glfwTerminate();
return -1;
}
glfwMakeContextCurrent(window);
glewInit();
char* vertexSource = load_shader_source("../shader.vert");
char* fragmentSource = load_shader_source("../shader.frag");
GLuint vertexShader = compile_shader(GL_VERTEX_SHADER, vertexSource);
GLuint fragmentShader = compile_shader(GL_FRAGMENT_SHADER, fragmentSource);
GLuint shaderProgram = glCreateProgram();
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
glLinkProgram(shaderProgram);
glUseProgram(shaderProgram);
GLint mouseLoc = glGetUniformLocation(shaderProgram, "u_mouse");
GLint timeLoc = glGetUniformLocation(shaderProgram, "u_time");
GLint resLoc = glGetUniformLocation(shaderProgram, "u_resolution");
glUniform1i(glGetUniformLocation(shaderProgram, "u_texture"), 0);
float vertices[] = {
// x, y, u, v
-1.0f, 1.0f, 0.0f, 1.0f,
1.0f, 1.0f, 1.0f, 1.0f,
1.0f, -1.0f, 1.0f, 0.0f,
-1.0f, -1.0f, 0.0f, 0.0f
};
unsigned int indices[] = {
0, 1, 2,
2, 3, 0
};
GLuint VAO, VBO, EBO;
glGenVertexArrays(1, &VAO);
glGenBuffers(1, &VBO);
glGenBuffers(1, &EBO);
glBindVertexArray(VAO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void*)(2 * sizeof(float)));
glEnableVertexAttribArray(1);
int width, height, nrChannels;
unsigned char *data = stbi_load("../texture.png", &width, &height, &nrChannels, 0);
if (!data) {
fprintf(stderr, "Failed to load texture\n");
return -1;
}
GLuint texture;
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
GLenum format = (nrChannels == 4) ? GL_RGBA : GL_RGB;
glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data);
glGenerateMipmap(GL_TEXTURE_2D);
stbi_image_free(data);
while (!glfwWindowShouldClose(window)) {
float timeValue = (float)glfwGetTime();
int winW, winH;
double mouseX, mouseY;
glfwGetCursorPos(window, &mouseX, &mouseY);
glfwGetWindowSize(window, &winW, &winH);
mouseY = winH - mouseY;
glClearColor(0.1f, 0.1f, 0.15f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
glUseProgram(shaderProgram);
glUniform1f(timeLoc, timeValue);
glUniform2f(mouseLoc, (float)mouseX, (float)mouseY);
glUniform2f(resLoc, (float)winW, (float)winH);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texture);
glBindVertexArray(VAO);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
glfwSwapBuffers(window);
glfwPollEvents();
}
glDeleteProgram(shaderProgram);
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
glfwTerminate();
return 0;
}
🔴shader.vert（頂点シェーダー）
#version 330 core
layout (location = 0) in vec2 aPos;
layout (location = 1) in vec2 aTexCoord;
out vec2 TexCoord;
void main() {
gl_Position = vec4(aPos, 0.0, 1.0);
TexCoord = aTexCoord;
}
🟣shader.frag（フラグメントシェーダー）
#version 330 core
out vec4 fragColor;
in vec2 TexCoord;
uniform sampler2D u_texture;
uniform vec2 u_mouse;
uniform vec2 u_resolution;
uniform float u_time;
void main() {
vec2 fragCoord = gl_FragCoord.xy;
float dist = distance(fragCoord, u_mouse);
float glow = 1.0 - smoothstep(0.0, 100.0, dist);
vec4 tex = texture(u_texture, TexCoord);
vec3 color = mix(tex.rgb, vec3(1.0, 1.0, 1.0), glow);
fragColor = vec4(color, 1.0);
}
で実行
furcr@furcraea_built MINGW64 /c/glsl_sample
$ cd glsl_sample_040
furcr@furcraea_built MINGW64 /c/glsl_sample/glsl_sample_040
$ mkdir build
furcr@furcraea_built MINGW64 /c/glsl_sample/glsl_sample_040
$ cd build
furcr@furcraea_built MINGW64 /c/glsl_sample/glsl_sample_040/build
$ cmake -G "MSYS Makefiles" ..
CMake Deprecation Warning at CMakeLists.txt:1 (cmake_minimum_required):
Compatibility with CMake < 3.10 will be removed from a future version of
CMake.
Update the VERSION argument <min> value. Or, use the <min>...<max> syntax
to tell CMake that the project requires at least <min> but has been updated
to work with policies introduced by <max> or earlier.
-- The C compiler identification is GNU 15.1.0
-- The CXX compiler identification is GNU 15.1.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: C:/msys64/mingw64/bin/cc.exe - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: C:/msys64/mingw64/bin/c++.exe - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found OpenGL: opengl32
-- Configuring done (1.2s)
-- Generating done (0.0s)
-- Build files have been written to: C:/glsl_sample/glsl_sample_040/build
furcr@furcraea_built MINGW64 /c/glsl_sample/glsl_sample_040/build
$ make
[ 50%] Building C object CMakeFiles/glsl_sample.dir/main.c.obj
[100%] Linking C executable glsl_sample.exe
[100%] Built target glsl_sample
furcr@furcraea_built MINGW64 /c/glsl_sample/glsl_sample_040/build
$ ./glsl_sample.exe
