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mirror of git://projects.qi-hardware.com/imgv.git synced 2024-11-27 16:56:15 +02:00
imgv/sdl-imageviewer.c
Xiangfu Liu f4ff893123 update to 0.2.1
Signed-off-by: Xiangfu Liu <xiangfu@sharism.cc>
2010-05-30 23:11:43 +08:00

401 lines
10 KiB
C

// imgv, a simple SDL-based image viewer for the Ben Nanonote
// Version 0.2.1
// Last edited by Fernando Carello <fcarello@libero.it> 2010-05-24
//
#include <stdlib.h>
#include <unistd.h>
#include <SDL/SDL.h>
#include <SDL/SDL_image.h>
#include <SDL/SDL_rotozoom.h>
#define TRUE 1
#define FALSE 0
#define SCREENWIDTH 320
#define SCREENHEIGHT 240
#define SCREENBPP 32
#define SMOOTHING_OFF 0
#define SMOOTHING_ON 1
#define PANSTEP 40
#define ZOOMSTEP 0.05
int main(int argc, char *argv[])
{
SDL_Surface *screen = NULL,
*scaled_img = NULL,
*temp_img = NULL,
*picture = NULL;
SDL_Event event;
SDL_Rect picturePortion,
screenPortion;
int imgWidth,
imgHeight,
smoothing = SMOOTHING_ON,
fPressed,
zPressed,
iPressed,
oPressed,
alreadyFit,
pixelFit,
lPressed,
rPressed,
leftPressed,
rightPressed,
upPressed,
downPressed;
char sFilename[255] = "\0",
sVersion[] = "0.2.1";
double scale_x = 1.0,
scale_y = 1.0,
scale = 1.0;
atexit(SDL_Quit);
// Process command line
if (argc != 2)
{
fprintf (stderr, "\n imgv v%s. Syntax: imgv <image file>\n\n Hotkeys:\n 'f' fit to screen\n 'z' zoom at pixel level\n 'i' zoom in 'o' zoom out\n 'l' rotate left 'r' rotate right\n 'arrows' pan 'ESC' quit\n\n", sVersion);
exit (1);
}
strncpy (sFilename, argv[1], 254);
// Initialize the SDL library
if (SDL_Init(SDL_INIT_VIDEO) < 0)
{
fprintf(stderr, "\n Couldn't initialize SDL: %s\n\n", SDL_GetError());
exit(1);
}
// Load Picture
temp_img = IMG_Load(sFilename);
if (temp_img == (SDL_Surface *) (NULL))
{
fprintf(stderr, "\n Couldn't load image file %s: %s\n\n", sFilename, SDL_GetError());
exit (1);
}
// Set video mode
screen = SDL_SetVideoMode
(SCREENWIDTH, SCREENHEIGHT, SCREENBPP, SDL_DOUBLEBUF | SDL_HWSURFACE | SDL_HWACCEL);
if (screen == (SDL_Surface *) (NULL))
{
fprintf(stderr, "Couldn't set %dx%dx%d video mode: %s\n\n", SCREENWIDTH, SCREENHEIGHT, SCREENBPP, SDL_GetError());
exit(1);
}
// Can't stand the useless arrow... Ben has no pointing device
SDL_ShowCursor(SDL_DISABLE);
// Convert picture in same format as video framebuffer, to optimize blit performances
picture = SDL_DisplayFormat (temp_img);
if (picture == (SDL_Surface *) (NULL))
{
fprintf(stderr, "\n Internal error from DisplayFormat\n\n");
exit (1);
}
SDL_FreeSurface (temp_img);
imgWidth = picture->w;
imgHeight = picture->h;
// Starting point (default view): uniform scaling to best screen fit, keep aspect ratio
scale_x = (double) (SCREENWIDTH) / (double) (imgWidth);
scale_y = (double) (SCREENHEIGHT) / (double) (imgHeight);
if (scale_y < scale_x)
scale = scale_y;
else
scale = scale_x;
scaled_img = zoomSurface (picture, scale, scale, SMOOTHING_ON);
if (scaled_img == (SDL_Surface *) (NULL))
{
fprintf (stderr, "\n Error from zoomSurface()\n\n");
exit (1);
}
screenPortion.x = 0; // destination coordinates: origin
screenPortion.y = 0;
picturePortion.x = 0;
picturePortion.y = 0;
picturePortion.w = (Uint16) imgWidth;
picturePortion.h = (Uint16) imgHeight;
// off-cycle: first image drawing
SDL_FillRect(screen, NULL, 0); // draw background color (black)
SDL_BlitSurface(scaled_img, &picturePortion, screen, &screenPortion);
SDL_Flip(screen);
leftPressed = FALSE;
rightPressed = FALSE;
upPressed = FALSE;
downPressed = FALSE;
fPressed = FALSE;
zPressed = FALSE;
lPressed = FALSE;
rPressed = FALSE;
iPressed = FALSE;
oPressed = FALSE;
pixelFit = FALSE;
alreadyFit = TRUE;
while(1)
{
if (SDL_WaitEvent( &event ))
{
// We only process SDL_KEYDOWN and SDL_KEYUP events
switch (event.type)
{
case SDL_KEYDOWN:
switch (event.key.keysym.sym)
{
case SDLK_LEFT:
leftPressed = TRUE;
break;
case SDLK_RIGHT:
rightPressed = TRUE;
break;
case SDLK_DOWN:
downPressed = TRUE;
break;
case SDLK_f:
fPressed = TRUE;
break;
case SDLK_z:
zPressed = TRUE;
break;
case SDLK_i:
iPressed = TRUE;
break;
case SDLK_o:
oPressed = TRUE;
break;
case SDLK_l:
lPressed = TRUE;
break;
case SDLK_r:
rPressed = TRUE;
break;
case SDLK_UP:
upPressed = TRUE;
break;
case SDLK_ESCAPE:
if (picture)
SDL_FreeSurface (picture);
if (scaled_img)
SDL_FreeSurface (scaled_img);
if (screen)
SDL_FreeSurface (screen);
exit(0);
default:
break;
}
break;
case SDL_KEYUP:
switch (event.key.keysym.sym)
{
case SDLK_LEFT:
leftPressed = FALSE;
break;
case SDLK_RIGHT:
rightPressed = FALSE;
break;
case SDLK_DOWN:
downPressed = FALSE;
break;
case SDLK_UP:
upPressed = FALSE;
break;
case SDLK_f:
fPressed = FALSE;
break;
case SDLK_z:
zPressed = FALSE;
break;
case SDLK_i:
iPressed = FALSE;
break;
case SDLK_o:
oPressed = FALSE;
break;
case SDLK_l:
lPressed = FALSE;
break;
case SDLK_r:
rPressed = FALSE;
break;
default:
break;
}
break;
} // end of switch (event.type)
// Process commands
if (fPressed && !alreadyFit)
{ // Fit image to screen
if (scaled_img != (SDL_Surface *) (NULL))
SDL_FreeSurface (scaled_img); // since zoomSurface() creates a new surface every time
alreadyFit = TRUE;
pixelFit = FALSE;
scale_x = (double) (SCREENWIDTH) / (double) (imgWidth);
scale_y = (double) (SCREENHEIGHT) / (double) (imgHeight);
if (scale_y < scale_x)
scale = scale_y;
else
scale = scale_x;
picturePortion.x = 0;
picturePortion.y = 0;
picturePortion.w = (Uint16) imgWidth;
picturePortion.h = (Uint16) imgHeight;
scaled_img = zoomSurface (picture, scale, scale, smoothing);
if (scaled_img == (SDL_Surface *) (NULL))
{
fprintf (stderr, "\n Error from zoomSurface()\n\n");
exit (1);
}
}
if (zPressed && !pixelFit)
{ // Zoom at 1:1 (100% zoom / actual pixels)
if (scaled_img != (SDL_Surface *) (NULL))
SDL_FreeSurface (scaled_img);
alreadyFit = FALSE;
pixelFit = TRUE;
picturePortion.w = (Uint16) SCREENWIDTH;
picturePortion.h = (Uint16) SCREENHEIGHT;
scale = 1.0;
scaled_img = SDL_ConvertSurface (picture, picture->format, picture->flags);
if (scaled_img == (SDL_Surface *) (NULL))
{
fprintf (stderr, "\n Error from ConvertSurface()\n\n");
exit (1);
}
}
if (iPressed)
{ // Zoom in
if (scaled_img != (SDL_Surface *) (NULL))
SDL_FreeSurface (scaled_img);
alreadyFit = FALSE;
pixelFit = FALSE;
scale += ZOOMSTEP;
picturePortion.w = (Uint16) ((double) (imgWidth) * scale);
if ( (picturePortion.w - picturePortion.x) >= imgWidth )
picturePortion.w = imgWidth - picturePortion.x;
if (picturePortion.w < 1)
picturePortion.w = 1;
picturePortion.h = (Uint16) ((double) (imgHeight) * scale);
if ( (picturePortion.h - picturePortion.y) >= imgHeight )
picturePortion.h = imgHeight - picturePortion.y;
if (picturePortion.h < 1)
picturePortion.h = 1;
scaled_img = zoomSurface (picture, scale, scale, smoothing);
//scaled_img = rotozoomSurface (picture, 0, scale, SMOOTHING_ON);
if (scaled_img == (SDL_Surface *) (NULL))
{
fprintf (stderr, "\n Error from zoomSurface()\n\n");
exit (1);
}
}
if (oPressed)
{ // Zoom out
if (scaled_img != (SDL_Surface *) (NULL))
SDL_FreeSurface (scaled_img);
alreadyFit = FALSE;
pixelFit = FALSE;
scale -= ZOOMSTEP;
if (scale <= 0.0)
scale = 0.01;
picturePortion.w = (Uint16) ((double) (imgWidth) * scale);
if ( (picturePortion.w - picturePortion.x) >= imgWidth)
picturePortion.w = imgWidth - picturePortion.x;
if (picturePortion.w < 1)
picturePortion.w = 1;
picturePortion.h = (Uint16) ((double) (imgHeight) * scale);
if ( (picturePortion.h - picturePortion.y) >= imgHeight )
picturePortion.h = imgHeight - picturePortion.y;
if (picturePortion.h < 1)
picturePortion.h = 1;
scaled_img = zoomSurface (picture, scale, scale, smoothing);
//scaled_img = rotozoomSurface (picture, 0, scale, SMOOTHING_ON);
if (scaled_img == (SDL_Surface *) (NULL))
{
fprintf (stderr, "\n Error from zoomSurface()\n\n");
exit (1);
}
}
if (lPressed)
{ // Rotate left 90°
if (scaled_img != (SDL_Surface *) (NULL))
temp_img = scaled_img;
else
{
fprintf (stderr, "\n Error: NULL scaled_img\n\n");
exit (1);
}
alreadyFit = FALSE;
scaled_img = rotozoomSurface (temp_img, -90, 1.0, SMOOTHING_OFF);
SDL_FreeSurface (temp_img);
if (scaled_img == (SDL_Surface *) (NULL))
{
fprintf (stderr, "\n Error from rotozoomSurface()\n\n");
exit (1);
}
}
if (rPressed)
{ // Rotate right 90°
if (scaled_img != (SDL_Surface *) (NULL))
temp_img = scaled_img;
else
{
fprintf (stderr, "\n Error: NULL scaled_img\n\n");
exit (1);
}
alreadyFit = FALSE;
scaled_img = rotozoomSurface (temp_img, 90, 1.0, SMOOTHING_OFF);
SDL_FreeSurface (temp_img);
if (scaled_img == (SDL_Surface *) (NULL))
{
fprintf (stderr, "\n Error from rotozoomSurface()\n\n");
exit (1);
}
}
if (leftPressed)
{
picturePortion.x -= PANSTEP;
if (picturePortion.x < 0)
picturePortion.x = 0;
alreadyFit = FALSE;
}
if (rightPressed)
{
picturePortion.x += PANSTEP;
if (picturePortion.x >= imgWidth)
picturePortion.x = (Sint16) (imgWidth - 1);
alreadyFit = FALSE;
}
if (upPressed)
{
picturePortion.y -= PANSTEP;
if (picturePortion.y < 0)
picturePortion.y = 0;
alreadyFit = FALSE;
}
if (downPressed)
{
picturePortion.y += PANSTEP;
if (picturePortion.y >= imgHeight)
picturePortion.y = (Sint16) (imgHeight - 1);
alreadyFit = FALSE;
}
SDL_FillRect(screen, (SDL_Rect *) NULL, 0); // draw background color (black)
SDL_BlitSurface(scaled_img, &picturePortion, screen, &screenPortion);
SDL_Flip(screen);
} // end of if(SDL_WaitEvent())
} // end of while(1)
return 0;
}