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/*
OSXIV - Overly Simple X Image Viewer
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <SDL2/SDL.h>
#include <SDL2/SDL_image.h>
#define DEBUG 0
int main(int argc, char** argv);
int render(double zoom, double move_x, double move_y);
int handle_events();
void cleanup();
#define DBG(fmt, ...) do { if (DEBUG) printf(fmt, __VA_ARGS__); } while (0)
SDL_Window *window = NULL;
SDL_Renderer *renderer = NULL;
SDL_Texture *texture = NULL;
int main(int argc, char** argv)
{
if(argc < 2)
{
fprintf(stderr, "Please provide a filename (or '-' to read from stdin).\n");
return 1;
}
if(strcmp(argv[1], "-") && access(argv[1], F_OK ) == -1)
{
fprintf(stderr, "Filename doesnt exist.\n");
return 1;
}
SDL_Init(SDL_INIT_VIDEO);
IMG_Init(IMG_INIT_PNG);
atexit(cleanup);
char* windowtitle = malloc(sizeof(char) * (9 + strlen(strcmp(argv[1], "-") ? argv[1] : "stdin"))); // +9 bcz "OSXIV - "
sprintf(windowtitle, "OSXIV - %s", strcmp(argv[1], "-") ? argv[1] : "stdin");
SDL_DisplayMode dm;
SDL_GetCurrentDisplayMode(0, &dm);
window = SDL_CreateWindow(
windowtitle,
SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED,
dm.w / 2, //w
dm.h / 2, //h
SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE
);
free(windowtitle);
renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_TARGETTEXTURE);
SDL_RWops* img;
if(!strcmp(argv[1], "-"))
img = SDL_RWFromFP(stdin, 0);
else
img = SDL_RWFromFile(argv[1], "rb");
texture = IMG_LoadTexture_RW(renderer, img, 0);
if(!texture)
{
SDL_FreeRW(img);
fprintf(stderr, "Problem while loading the image: (%s).\n", argv[1]);
return 1;
}
SDL_FreeRW(img);
if(handle_events())
{
fprintf(stderr, "Event handling exception.\n");
return 1;
}
return 0;
}
int render(double zoom, double move_x, double move_y)
{
SDL_Rect src = {0};
SDL_Rect dst = {0};
int screen_h, screen_w;
SDL_RenderClear(renderer);
SDL_QueryTexture(texture, NULL, NULL, &src.w , &src.h);
DBG("\nsrc w: %d h: %d x: %d y: %d\n", src.w, src.h, src.x, src.y);
SDL_GetWindowSize(window, &dst.w, &dst.h);
screen_h = dst.h;
screen_w = dst.w;
DBG("scr w: %d h: %d\n", screen_w, screen_h);
/* APPLY ZOOM */
dst.h *= zoom;
dst.w *= zoom;
DBG("zoom: %f\n", zoom);
/* REVERT IMAGE FILL */
double ratio = (double) src.w / src.h;
if(dst.h >= dst.w / ratio)
dst.h = dst.w / ratio;
else
dst.w = ratio * dst.h;
/* CENTER IN SCREEN */
dst.x = (screen_w - dst.w) / 2;
dst.y = (screen_h - dst.h) / 2;
DBG("dst w: %d h: %d x: %d y: %d\n\n", dst.w, dst.h, dst.x, dst.y);
/* APPLY MOVE */
dst.x -= move_x * dst.w;
dst.y -= move_y * dst.h;
DBG("Moved by x_perc: %f y_perc: %f\n", move_x, move_y);
SDL_RenderCopy(renderer, texture, &src, &dst);
SDL_RenderPresent(renderer);
return 0;
}
int handle_events()
{
SDL_Event event;
double zoom_multiplier = 0.1; // 10%
double move_multipler = 0.1; // 10%
double zoom = 1.0; // 100% initially
double move_x = 0.0; // initial x pos (centered)
double move_y = 0.0; // initial y pos (centered)
while(SDL_WaitEvent(&event))
{
//DBG("Event: 0x%x\n", event.type);
switch(event.type)
{
case SDL_KEYDOWN:
switch(event.key.keysym.sym)
{
case '+': // zoom in
case 61: // +
zoom += zoom_multiplier;
render(zoom, move_x, move_y);
break;
case '-': // zoom out
zoom -= zoom - zoom_multiplier < 0 ? 0 : zoom_multiplier;
render(zoom, move_x, move_y);
break;
case 1073741906: // up arrow - move up
move_y -= move_multipler / zoom;
render(zoom, move_x, move_y);
break;
case 1073741905: // down arrow - move down
move_y += move_multipler / zoom;
render(zoom, move_x, move_y);
break;
case 1073741904: // left arrow - move left
move_x -= move_multipler / zoom;
render(zoom, move_x, move_y);
break;
case 1073741903: // right arrow - move right
move_x += move_multipler / zoom;
render(zoom, move_x, move_y);
break;
case 'q':
exit(0);
}
break;
case SDL_WINDOWEVENT:
render(zoom, move_x, move_y);
break;
case SDL_QUIT:
exit(0);
}
}
return 1;
}
void cleanup()
{
SDL_DestroyTexture(texture);
SDL_DestroyRenderer(renderer);
SDL_DestroyWindow(window);
IMG_Quit();
SDL_Quit();
}
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