tuxpaint-pencil-sharpener/magic/src/googlyeyes.c

/* googlyeyes.c

   Draws a googly eye at the click position, and looks
   towards where you drag+release.

  Last updated: April 18, 2023
*/

#include <stdio.h>
#include <string.h>
#include <libintl.h>
#include <math.h>

#include "tp_magic_api.h"
#include "SDL_image.h"
#include "SDL_mixer.h"

/* For when Tux Paint is run with "--nomagicsizes", we'll present two tools */

#define NUM_SIZES 2
int sizes[NUM_SIZES] = { 100, 50 };

char *googlyeyes_descr[NUM_SIZES] = {
  gettext_noop("Click to place a large googly eye, then drag and release to make it look that direction."),
  gettext_noop("Click to place a small googly eye, then drag and release to make it look that direction."),
};

char *img_filenames[NUM_SIZES] = {
  "googlyeyes.png",             // Also used with magic sizes
  "googlyeyes-sm.png"
};

#define NUM_SCALEABLE_SIZES 4

int googlyeyes_limited = 0;
int googlyeyes_sizes;
int googlyeyes_size;
Mix_Chunk *snd_effect = NULL;
SDL_Surface **googlyeyes_img_bkgd = NULL;
SDL_Surface **googlyeyes_img_pupil = NULL;
SDL_Surface **googlyeyes_img_reflection = NULL;
int eye_x, eye_y;

Uint32 googlyeyes_api_version(void);
int googlyeyes_init(magic_api * api, Uint32 disabled_features);
int googlyeyes_get_tool_count(magic_api * api);
SDL_Surface *googlyeyes_get_icon(magic_api * api, int which);
char *googlyeyes_get_name(magic_api * api, int which);
int googlyeyes_get_group(magic_api * api, int which);
char *googlyeyes_get_description(magic_api * api, int which, int mode);
int googlyeyes_requires_colors(magic_api * api, int which);
int googlyeyes_modes(magic_api * api, int which);
Uint8 googlyeyes_accepted_sizes(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED,
                                int mode ATTRIBUTE_UNUSED);
Uint8 googlyeyes_default_size(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED, int mode ATTRIBUTE_UNUSED);
void googlyeyes_shutdown(magic_api * api);
void googlyeyes_click(magic_api * api, int which, int mode,
                      SDL_Surface * canvas, SDL_Surface * snapshot, int x, int y, SDL_Rect * update_rect);
void googlyeyes_set_color(magic_api * api, int which, SDL_Surface * canvas,
                          SDL_Surface * last, Uint8 r, Uint8 g, Uint8 b, SDL_Rect * update_rect);
void googlyeyes_set_size(magic_api * api, int which, int mode,
                         SDL_Surface * canvas, SDL_Surface * last, Uint8 sz, SDL_Rect * update_rect);
void googlyeyes_drag(magic_api * api, int which, SDL_Surface * canvas,
                     SDL_Surface * snapshot, int ox, int oy, int x, int y, SDL_Rect * update_rect);
void googlyeyes_release(magic_api * api, int which, SDL_Surface * canvas,
                        SDL_Surface * snapshot, int x, int y, SDL_Rect * update_rect);
void googlyeyes_switchin(magic_api * api, int which, int mode, SDL_Surface * canvas);
void googlyeyes_switchout(magic_api * api, int which, int mode, SDL_Surface * canvas);


Uint32 googlyeyes_api_version(void)
{
  return (TP_MAGIC_API_VERSION);
}

int googlyeyes_init(magic_api * api, Uint32 disabled_features)
{
  char fname[1024];
  int i;

  googlyeyes_limited = (disabled_features & MAGIC_FEATURE_SIZE);

  /* Load sound effect */
  snprintf(fname, sizeof(fname), "%ssounds/magic/googlyeyes.ogg", api->data_directory);
  snd_effect = Mix_LoadWAV(fname);

  /* Init the images */
  if (googlyeyes_limited)
  {
    googlyeyes_sizes = NUM_SIZES;
  }
  else
  {
    googlyeyes_sizes = NUM_SCALEABLE_SIZES;
  }

  googlyeyes_img_bkgd = (SDL_Surface * *)malloc(sizeof(SDL_Surface *) * googlyeyes_sizes);
  googlyeyes_img_pupil = (SDL_Surface * *)malloc(sizeof(SDL_Surface *) * googlyeyes_sizes);
  googlyeyes_img_reflection = (SDL_Surface * *)malloc(sizeof(SDL_Surface *) * googlyeyes_sizes);

  for (i = 0; i < googlyeyes_sizes; i++)
  {
    googlyeyes_img_bkgd[i] = NULL;
    googlyeyes_img_pupil[i] = NULL;
    googlyeyes_img_reflection[i] = NULL;
  }

  /* Load the base images (100% scale) */
  snprintf(fname, sizeof(fname), "%simages/magic/googly-eyes-bkgd.png", api->data_directory);
  googlyeyes_img_bkgd[0] = IMG_Load(fname);
  if (googlyeyes_img_bkgd[0] == NULL)
  {
    fprintf(stderr, "Can't open %s\n", fname);
    return 0;
  }

  snprintf(fname, sizeof(fname), "%simages/magic/googly-eyes-pupil.png", api->data_directory);
  googlyeyes_img_pupil[0] = IMG_Load(fname);
  if (googlyeyes_img_pupil[0] == NULL)
  {
    fprintf(stderr, "Can't open %s\n", fname);
    return 0;
  }

  snprintf(fname, sizeof(fname), "%simages/magic/googly-eyes-reflection.png", api->data_directory);
  googlyeyes_img_reflection[0] = IMG_Load(fname);
  if (googlyeyes_img_reflection[0] == NULL)
  {
    fprintf(stderr, "Can't open %s\n", fname);
    return 0;
  }

  /* Create the scaled versions */
  for (i = 1; i < googlyeyes_sizes; i++)
  {
    int size;

    if (googlyeyes_limited)
    {
      size = sizes[i];
    }
    else
    {
      size = (100 * (googlyeyes_sizes - i)) / googlyeyes_sizes;
    }

    googlyeyes_img_bkgd[i] = api->scale(googlyeyes_img_bkgd[0],
                                        (googlyeyes_img_bkgd[0]->w * size) / 100,
                                        (googlyeyes_img_bkgd[0]->h * size) / 100, 1);

    if (googlyeyes_img_bkgd[i] == NULL)
    {
      fprintf(stderr, "Cannot scale bkgd to %d%%", size);
      return (1);
    }

    googlyeyes_img_pupil[i] = api->scale(googlyeyes_img_pupil[0],
                                         (googlyeyes_img_pupil[0]->w * size) / 100,
                                         (googlyeyes_img_pupil[0]->h * size) / 100, 1);

    if (googlyeyes_img_pupil[i] == NULL)
    {
      fprintf(stderr, "Cannot scale pupil to %d%%", size);
      return (1);
    }

    googlyeyes_img_reflection[i] = api->scale(googlyeyes_img_reflection[0],
                                              (googlyeyes_img_reflection[0]->w * size) / 100,
                                              (googlyeyes_img_reflection[0]->h * size) / 100, 1);

    if (googlyeyes_img_reflection[i] == NULL)
    {
      fprintf(stderr, "Cannot scale reflection to %d%%", size);
      return (1);
    }
  }

  return (1);
}

int googlyeyes_get_tool_count(magic_api * api ATTRIBUTE_UNUSED)
{
  if (googlyeyes_limited)
  {
    return (NUM_SIZES);
  }
  else
  {
    return 1;
  }
}


SDL_Surface *googlyeyes_get_icon(magic_api * api, int which)
{
  char fname[1024];

  snprintf(fname, sizeof(fname), "%simages/magic/%s", api->data_directory, img_filenames[which]);

  return (IMG_Load(fname));
}

char *googlyeyes_get_name(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED)
{
  return strdup(gettext("Googly Eyes"));
}

int googlyeyes_get_group(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED)
{
  return MAGIC_TYPE_ARTISTIC;
}

char *googlyeyes_get_description(magic_api * api ATTRIBUTE_UNUSED,
                                 int which ATTRIBUTE_UNUSED, int mode ATTRIBUTE_UNUSED)
{
  if (googlyeyes_limited)
  {
    return strdup(gettext(googlyeyes_descr[which]));
  }
  else
  {
    return strdup(gettext_noop("Click to place a googly eye, then drag and release to make it look that direction."));
  }
}

int googlyeyes_requires_colors(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED)
{
  return 0;
}

int googlyeyes_modes(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED)
{
  return MODE_PAINT;
}

Uint8 googlyeyes_accepted_sizes(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED, int mode ATTRIBUTE_UNUSED)
{
  if (googlyeyes_limited)
  {
    return 1;
  }
  else
  {
    return NUM_SCALEABLE_SIZES;
  }
}

Uint8 googlyeyes_default_size(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED, int mode ATTRIBUTE_UNUSED)
{
  return NUM_SCALEABLE_SIZES;
}

void googlyeyes_shutdown(magic_api * api ATTRIBUTE_UNUSED)
{
  int i;

  if (snd_effect != NULL)
    Mix_FreeChunk(snd_effect);

  for (i = 0; i < googlyeyes_sizes; i++)
  {
    if (googlyeyes_img_bkgd[i] != NULL)
      SDL_FreeSurface(googlyeyes_img_bkgd[i]);

    if (googlyeyes_img_pupil[i] != NULL)
      SDL_FreeSurface(googlyeyes_img_pupil[i]);

    if (googlyeyes_img_reflection[i] != NULL)
      SDL_FreeSurface(googlyeyes_img_reflection[i]);
  }

  free(googlyeyes_img_bkgd);
  free(googlyeyes_img_pupil);
  free(googlyeyes_img_reflection);
}


void
googlyeyes_click(magic_api * api, int which, int mode ATTRIBUTE_UNUSED,
                 SDL_Surface * canvas, SDL_Surface * snapshot, int x, int y, SDL_Rect * update_rect)
{
  int img;

  eye_x = x;
  eye_y = y;

  if (googlyeyes_limited)
  {
    img = which;
  }
  else
  {
    img = googlyeyes_size - 1;
  }

  if (eye_x < googlyeyes_img_bkgd[img]->w / 2)
    eye_x = googlyeyes_img_bkgd[img]->w / 2;
  if (eye_y < googlyeyes_img_bkgd[img]->h / 2)
    eye_y = googlyeyes_img_bkgd[img]->h / 2;

  api->stopsound();
  api->playsound(snd_effect, (x * 255) / canvas->w, 255);

  googlyeyes_drag(api, which, canvas, snapshot, x, y, x, y, update_rect);
}


void
googlyeyes_drag(magic_api * api ATTRIBUTE_UNUSED, int which, SDL_Surface * canvas,
                SDL_Surface * snapshot, int ox ATTRIBUTE_UNUSED,
                int oy ATTRIBUTE_UNUSED, int x, int y, SDL_Rect * update_rect)
{
  SDL_Rect dest;
  int max_radius;
  int img;

  if (googlyeyes_limited)
  {
    img = which;
  }
  else
  {
    img = googlyeyes_size - 1;
  }

  /* Set the destination for the main background */
  update_rect->x = eye_x - googlyeyes_img_bkgd[img]->w / 2;
  update_rect->y = eye_y - googlyeyes_img_bkgd[img]->h / 2;
  update_rect->w = googlyeyes_img_bkgd[img]->w;
  update_rect->h = googlyeyes_img_bkgd[img]->h;

  /* Erase the eye (drop snapshot pixels back into canvas) */
  SDL_BlitSurface(snapshot, update_rect, canvas, update_rect);

  /* 1. Draw the background */
  SDL_BlitSurface(googlyeyes_img_bkgd[img], NULL, canvas, update_rect);

  /* 2. Draw the pupil */
  max_radius = ((googlyeyes_img_bkgd[img]->w - googlyeyes_img_pupil[img]->w) / 2);
  if (sqrt(((x - eye_x) * (x - eye_x)) + ((y - eye_y) * (y - eye_y))) > max_radius)
  {
    /* If drag position would place pupil outside the circular bounds
     * of the background, put it on the edge, "looking towards" (pointing at)
     * the mouse. */
    /* (Calculations borrowed from Xeyes' "computePupil()",
     * https://github.com/freedesktop/xorg-xeyes/blob/master/Eyes.c) */
    double dx, dy, angle;

    dx = (double)(x - eye_x);
    dy = (double)(y - eye_y);
    angle = atan2(dy, dx);

    x = eye_x + (cos(angle) * max_radius);
    y = eye_y + (sin(angle) * max_radius);
  }

  dest.x = x - googlyeyes_img_pupil[img]->w / 2;
  dest.y = y - googlyeyes_img_pupil[img]->h / 2;
  dest.w = googlyeyes_img_pupil[img]->w;
  dest.h = googlyeyes_img_pupil[img]->h;
  SDL_BlitSurface(googlyeyes_img_pupil[img], NULL, canvas, &dest);

  /* 3. Draw the reflection */
  dest.x = eye_x - googlyeyes_img_reflection[img]->w / 2;
  dest.y = eye_y - googlyeyes_img_reflection[img]->h / 2;
  dest.w = googlyeyes_img_reflection[img]->w;
  dest.h = googlyeyes_img_reflection[img]->h;
  SDL_BlitSurface(googlyeyes_img_reflection[img], NULL, canvas, &dest);
}


void
googlyeyes_release(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED,
                   SDL_Surface * canvas ATTRIBUTE_UNUSED, SDL_Surface * snapshot ATTRIBUTE_UNUSED,
                   int x ATTRIBUTE_UNUSED, int y ATTRIBUTE_UNUSED, SDL_Rect * update_rect ATTRIBUTE_UNUSED)
{
}


void googlyeyes_set_color(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED,
                          SDL_Surface * canvas ATTRIBUTE_UNUSED, SDL_Surface * last ATTRIBUTE_UNUSED,
                          Uint8 r ATTRIBUTE_UNUSED, Uint8 g ATTRIBUTE_UNUSED, Uint8 b ATTRIBUTE_UNUSED,
                          SDL_Rect * update_rect ATTRIBUTE_UNUSED)
{
}


void googlyeyes_set_size(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED, int mode ATTRIBUTE_UNUSED,
                         SDL_Surface * canvas ATTRIBUTE_UNUSED, SDL_Surface * last ATTRIBUTE_UNUSED,
                         Uint8 sz, SDL_Rect * update_rect ATTRIBUTE_UNUSED)
{
  googlyeyes_size = (NUM_SCALEABLE_SIZES - sz) + 1;
}

void googlyeyes_switchin(magic_api * api ATTRIBUTE_UNUSED,
                         int which ATTRIBUTE_UNUSED, int mode ATTRIBUTE_UNUSED, SDL_Surface * canvas ATTRIBUTE_UNUSED)
{
}

void googlyeyes_switchout(magic_api * api ATTRIBUTE_UNUSED,
                          int which ATTRIBUTE_UNUSED, int mode ATTRIBUTE_UNUSED, SDL_Surface * canvas ATTRIBUTE_UNUSED)
{
}