Files
cpp-imanox-chroma-matting/opengl-test-two/main.cpp
2016-09-01 15:08:26 +02:00

117 lines
3.6 KiB
C++

#include <GLFW/glfw3.h>
#include <SDL2/SDL.h>
#include <SDL2/SDL_image.h>
#include <stdio.h>
#include <iostream>
GLuint loadBMP_custom(const char * imagepath);
void EnableTransparency()
{
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}
GLuint LoadTexture(char *filename,int *textw,int *texth) {
SDL_Surface *surface;
GLuint textureid;
int mode;
surface = IMG_Load(filename);
// Or if you don't use SDL_image you can use SDL_LoadBMP here instead:
// surface = SDL_LoadBMP(filename);
// could not load filename
if (!surface) {
return 0;
}
// work out what format to tell glTexImage2D to use...
if (surface->format->BytesPerPixel == 3) { // RGB 24bit
mode = GL_RGB;
} else if (surface->format->BytesPerPixel == 4) { // RGBA 32bit
mode = GL_RGBA;
} else {
SDL_FreeSurface(surface);
return 0;
}
*textw=surface->w;
*texth=surface->h;
// create one texture name
glGenTextures(1, &textureid);
// tell opengl to use the generated texture name
glBindTexture(GL_TEXTURE_2D, textureid);
// this reads from the sdl surface and puts it into an opengl texture
glTexImage2D(GL_TEXTURE_2D, 0, mode, surface->w, surface->h, 0, mode, GL_UNSIGNED_BYTE, surface->pixels);
// these affect how this texture is drawn later on...glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
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);
// clean up
SDL_FreeSurface(surface);
return textureid;
}
void DrawTexture(int x, int y, GLuint textureid,int textw,int texth) {
//printf("x: %d\ty: %d\tw: %d\th: %d\n", x, y, textw, texth);
//int textw,texth;
// tell opengl to use the generated texture name
glBindTexture(GL_TEXTURE_2D, textureid);
glEnable(GL_TEXTURE_2D);
// make a rectangle
glBegin(GL_QUADS);
glTexCoord2d(0.0,0.0); glVertex2f(-1, -1);
glTexCoord2d(1.0,0.0); glVertex2f(1, -1);
glTexCoord2d(1.0,1.0); glVertex2f(1, 1);
glTexCoord2d(0.0,1.0); glVertex2f(-1, 1);
glEnd();
glDisable(GL_TEXTURE_2D );
}
int main(int argc, char* args[]) {
GLFWwindow* window;
GLuint myglu;
int textw, texth;
/* Initialize the library */
/* GLFW */
if (!glfwInit())
return -1;
/* SDL */
if (SDL_Init(SDL_INIT_VIDEO) < 0)
printf("SDL Error");
/* Create a windowed mode window and its OpenGL context */
window = glfwCreateWindow(640, 480, "Hello World", NULL, NULL);
if (!window) {
glfwTerminate();
return -1;
}
/* Make the window's context current */
glfwMakeContextCurrent(window);
// INIT
myglu=LoadTexture("../img/tests/stones.bmp",&textw,&texth);
// INIT END
/* Loop until the user closes the window */
while (!glfwWindowShouldClose(window)) {
/* Render here */
glClear(GL_COLOR_BUFFER_BIT);
// RENDER
DrawTexture(50,50,myglu,textw,texth);
// RENDER END
/* Swap front and back buffers */
glfwSwapBuffers(window);
/* Poll for and process events */
glfwPollEvents();
}
glfwTerminate();
return 0;
}