148 lines
3.9 KiB
C++
148 lines
3.9 KiB
C++
#include <GL/glew.h>
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#include <GLFW/glfw3.h>
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#define STB_IMAGE_IMPLEMENTATION
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#include "stb_image.hpp"
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#define STB_IMAGE_WRITE_IMPLEMENTATION
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#include "stb_image_write.hpp"
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#include <fstream>
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#include <vector>
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#include <iostream>
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std::string loadFile(const char* path)
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{
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std::ifstream f(path);
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return std::string((std::istreambuf_iterator<char>(f)),
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std::istreambuf_iterator<char>());
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}
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GLuint compile(GLenum t, const std::string& src)
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{
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GLuint s = glCreateShader(t);
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const char* c = src.c_str();
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glShaderSource(s, 1, &c, NULL);
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glCompileShader(s);
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return s;
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}
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int main()
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{
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glfwInit();
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glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE);
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GLFWwindow* win = glfwCreateWindow(1,1,"",NULL,NULL);
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glfwMakeContextCurrent(win);
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glewInit();
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// ---------------- LOAD IMAGES ----------------
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int w,h,c;
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unsigned char* img1 = stbi_load("frame1.jpg",&w,&h,&c,4);
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unsigned char* img2 = stbi_load("frame2.jpg",&w,&h,&c,4);
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if(!img1 || !img2)
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{
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std::cout << "image load failed\n";
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return 0;
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}
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// ---------------- TEXTURES ----------------
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GLuint texA, texB;
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glGenTextures(1,&texA);
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glGenTextures(1,&texB);
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auto upload = [&](GLuint t, unsigned char* d)
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{
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glBindTexture(GL_TEXTURE_2D,t);
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glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,w,h,0,GL_RGBA,GL_UNSIGNED_BYTE,d);
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glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);
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glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
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glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_CLAMP_TO_EDGE);
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glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_CLAMP_TO_EDGE);
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};
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upload(texA,img1);
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upload(texB,img2);
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// ---------------- SHADER ----------------
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std::string frag = loadFile("motion.frag");
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const char* vs =
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"#version 330 core\n"
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"layout(location=0) in vec2 pos;\n"
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"out vec2 uv;\n"
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"void main(){\n"
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"uv = pos*0.5+0.5;\n"
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"gl_Position = vec4(pos,0,1);\n"
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"}";
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GLuint v = compile(GL_VERTEX_SHADER,vs);
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GLuint f = compile(GL_FRAGMENT_SHADER,frag);
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GLuint prog = glCreateProgram();
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glAttachShader(prog,v);
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glAttachShader(prog,f);
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glLinkProgram(prog);
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// ---------------- QUAD (FIXED) ----------------
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GLuint vao,vbo;
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float quad[] = {
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-1,-1,
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1,-1,
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-1, 1,
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1, 1
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};
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glGenVertexArrays(1,&vao);
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glBindVertexArray(vao);
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glGenBuffers(1,&vbo);
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glBindBuffer(GL_ARRAY_BUFFER,vbo);
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glBufferData(GL_ARRAY_BUFFER,sizeof(quad),quad,GL_STATIC_DRAW);
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glVertexAttribPointer(0,2,GL_FLOAT,GL_FALSE,0,0);
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glEnableVertexAttribArray(0);
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// ---------------- FBO ----------------
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GLuint fbo,outTex;
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glGenFramebuffers(1,&fbo);
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glGenTextures(1,&outTex);
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glBindTexture(GL_TEXTURE_2D,outTex);
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glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,w,h,0,GL_RGBA,GL_UNSIGNED_BYTE,NULL);
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glBindFramebuffer(GL_FRAMEBUFFER,fbo);
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glFramebufferTexture2D(GL_FRAMEBUFFER,GL_COLOR_ATTACHMENT0,GL_TEXTURE_2D,outTex,0);
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if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
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std::cout << "FBO broken\n";
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// ---------------- RENDER ----------------
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glUseProgram(prog);
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glActiveTexture(GL_TEXTURE0);
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glBindTexture(GL_TEXTURE_2D,texA);
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glUniform1i(glGetUniformLocation(prog,"texA"),0);
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glActiveTexture(GL_TEXTURE1);
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glBindTexture(GL_TEXTURE_2D,texB);
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glUniform1i(glGetUniformLocation(prog,"texB"),1);
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glViewport(0,0,w,h);
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glBindFramebuffer(GL_FRAMEBUFFER,fbo);
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glBindVertexArray(vao);
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glDrawArrays(GL_TRIANGLE_STRIP,0,4);
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// ---------------- READ BACK ----------------
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std::vector<unsigned char> out(w*h*4);
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glReadPixels(0,0,w,h,GL_RGBA,GL_UNSIGNED_BYTE,out.data());
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stbi_write_jpg("frameO.jpg",w,h,4,out.data(),90);
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std::cout << "done\n";
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}
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