1 /*
2  * Folds the picture down from the corners.
3  *
4  * Last updated: 2019-08-29
5  */
6 
7 //optimized version soon :)
8 //when "folding" same corner many times it gives strange results. Now it's allowed. Let me know
9 //if you think it shouldn't be.
10 
11 //sound playing needs fixing.
12 
13 #include "tp_magic_api.h"
14 #include "SDL_image.h"
15 #include "SDL_mixer.h"
16 
17 #define FOLD_LEN 80
18 
19 int right_arm_x, right_arm_y, left_arm_x, left_arm_y;
20 int fold_ox, fold_oy;
21 int fold_x, fold_y;
22 Uint8 fold_shadow_value;
23 Uint8 corner;
24 Mix_Chunk *fold_snd;
25 Uint8 fold_r, fold_g, fold_b;
26 Uint32 fold_color;
27 SDL_Surface *fold_surface_src, *fold_surface_dst;
28 
29 
30 void fold_draw(magic_api * api, int which,
31                SDL_Surface * canvas, SDL_Surface * snapshot, int x, int y, SDL_Rect * update_rect);
32 static void fold_erase(void *ptr, int which, SDL_Surface * canvas, SDL_Surface * last, int x, int y);
33 void translate_coords(SDL_Surface * canvas, int angle);
34 SDL_Surface *rotate(magic_api * api, SDL_Surface * canvas, int angle);
35 void fold_draw(magic_api * api, int which,
36                SDL_Surface * canvas, SDL_Surface * snapshot, int x, int y, SDL_Rect * update_rect);
37 static void fold_print_line(void *ptr, int which, SDL_Surface * canvas, SDL_Surface * last, int x, int y);
38 static void fold_print_dark_line(void *ptr, int which, SDL_Surface * canvas, SDL_Surface * last, int x, int y);
39 void translate_xy(SDL_Surface * canvas, int x, int y, int *a, int *b, int rotation);
40 Uint32 fold_api_version(void);
41 void fold_set_color(magic_api * api, Uint8 r, Uint8 g, Uint8 b);
42 int fold_init(magic_api * api);
43 int fold_get_tool_count(magic_api * api);
44 SDL_Surface *fold_get_icon(magic_api * api, int which);
45 char *fold_get_name(magic_api * api, int which);
46 char *fold_get_description(magic_api * api, int which, int mode);
47 int fold_requires_colors(magic_api * api, int which);
48 void fold_release(magic_api * api, int which,
49                   SDL_Surface * canvas, SDL_Surface * snapshot, int x, int y, SDL_Rect * update_rect);
50 void fold_shutdown(magic_api * api);
51 void fold_click(magic_api * ptr, int which, int mode,
52                 SDL_Surface * canvas, SDL_Surface * snapshot, int x, int y, SDL_Rect * update_rect);
53 void fold_preview(magic_api * api, int which, SDL_Surface * canvas,
54                   SDL_Surface * snapshot, int ox, int oy, int x, int y, SDL_Rect * update_rect);
55 int fold_modes(magic_api * api, int which);
56 
57 //                              Housekeeping functions
58 
59 void fold_drag(magic_api * api, int which, SDL_Surface * canvas,
60                SDL_Surface * snapshot, int ox, int oy, int x, int y, SDL_Rect * update_rect);
61 void fold_switchin(magic_api * api, int which, int mode, SDL_Surface * canvas);
62 inline Uint8 fold_what_corner(int x, int y, SDL_Surface * canvas);
63 void fold_switchout(magic_api * api, int which, int mode, SDL_Surface * canvas);
64 
fold_api_version(void)65 Uint32 fold_api_version(void)
66 {
67   return (TP_MAGIC_API_VERSION);
68 }
69 
fold_set_color(magic_api * api ATTRIBUTE_UNUSED,Uint8 r,Uint8 g,Uint8 b)70 void fold_set_color(magic_api * api ATTRIBUTE_UNUSED, Uint8 r, Uint8 g, Uint8 b)        //get the colors from API and store it in structure
71 {
72   fold_r = r;
73   fold_g = g;
74   fold_b = b;
75 }
76 
fold_init(magic_api * api)77 int fold_init(magic_api * api)
78 {
79   char fname[1024];
80 
81   snprintf(fname, sizeof(fname), "%s/sounds/magic/fold.wav", api->data_directory);
82   fold_snd = Mix_LoadWAV(fname);
83 
84   return (1);
85 }
86 
fold_get_tool_count(magic_api * api ATTRIBUTE_UNUSED)87 int fold_get_tool_count(magic_api * api ATTRIBUTE_UNUSED)
88 {
89   return 1;
90 }
91 
fold_get_icon(magic_api * api ATTRIBUTE_UNUSED,int which ATTRIBUTE_UNUSED)92 SDL_Surface *fold_get_icon(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED)
93 {
94   char fname[1024];
95 
96   snprintf(fname, sizeof(fname), "%s/images/magic/fold.png", api->data_directory);
97 
98   return (IMG_Load(fname));
99 }
100 
fold_get_name(magic_api * api ATTRIBUTE_UNUSED,int which ATTRIBUTE_UNUSED)101 char *fold_get_name(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED)
102 {
103   return (gettext_noop("Fold"));
104 }
105 
fold_get_description(magic_api * api ATTRIBUTE_UNUSED,int which ATTRIBUTE_UNUSED,int mode ATTRIBUTE_UNUSED)106 char *fold_get_description(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED, int mode ATTRIBUTE_UNUSED)
107 {
108   return strdup(gettext_noop("Choose a background color and click to turn the corner of the page over."));
109 }
110 
fold_requires_colors(magic_api * api ATTRIBUTE_UNUSED,int which ATTRIBUTE_UNUSED)111 int fold_requires_colors(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED)
112 {
113   return 1;
114 }                               //selected color will be a "backpage" color
115 
116 
fold_shadow(void * ptr,int which ATTRIBUTE_UNUSED,SDL_Surface * canvas,SDL_Surface * temp,int x,int y)117 static void fold_shadow(void *ptr, int which ATTRIBUTE_UNUSED, SDL_Surface * canvas, SDL_Surface * temp, int x, int y)
118 {
119   magic_api *api = (magic_api *) ptr;
120   Uint8 r, g, b, a;
121 
122   SDL_GetRGBA(api->getpixel(temp, x, y), temp->format, &r, &g, &b, &a);
123   api->putpixel(canvas, x, y, SDL_MapRGBA(canvas->format,
124                                           max(r - 160 + fold_shadow_value * 4, 0), max(g - 160 + fold_shadow_value * 4,
125                                                                                        0),
126                                           max(b - 160 + fold_shadow_value * 4, 0), a));
127 }
128 
fold_draw(magic_api * api,int which,SDL_Surface * canvas,SDL_Surface * snapshot,int x,int y,SDL_Rect * update_rect ATTRIBUTE_UNUSED)129 void fold_draw(magic_api * api, int which,
130                SDL_Surface * canvas, SDL_Surface * snapshot, int x, int y, SDL_Rect * update_rect ATTRIBUTE_UNUSED)
131 {
132   float right_step_x, right_step_y, left_step_x, left_step_y;
133   float dist_x, dist_y;
134   int left_y, right_x;
135   float w, h;
136   SDL_Surface *temp;
137 
138   temp = SDL_CreateRGBSurface(SDL_ANYFORMAT, canvas->w, canvas->h, canvas->format->BitsPerPixel,
139                               canvas->format->Rmask, canvas->format->Gmask, canvas->format->Bmask,
140                               canvas->format->Amask);
141   SDL_BlitSurface(canvas, 0, temp, 0);
142 
143   right_step_x = (float)(x - left_arm_x) / (float)(left_arm_x - fold_ox);
144   right_step_y = (float)(y - left_arm_y) / (float)(left_arm_x - fold_ox);
145   left_step_x = (float)(x - right_arm_x) / (float)(right_arm_y - fold_oy);
146   left_step_y = (float)(y - right_arm_y) / (float)(right_arm_y - fold_oy);
147 
148   left_y = (float)right_arm_y / left_arm_x * (left_arm_x - canvas->w);
149   right_x = (float)left_arm_x / right_arm_y * (right_arm_y - canvas->h);
150 
151   for (w = 0; w < canvas->w; w += 0.5)
152     {
153       for (h = 0; h < canvas->h; h += 0.5)
154         {
155           dist_x = right_step_x * w + left_step_x * h;
156           dist_y = right_step_y * w + left_step_y * h;
157           api->putpixel(canvas, x - dist_x, y - dist_y, api->getpixel(temp, w, h));
158         }
159     }
160 
161   // Erasing the triangle.
162   // The 1 pixel in plus  is a workaround for api-line not getting the end in some lines.
163   if (left_arm_x > canvas->w)
164     {
165       for (h = 0; h <= right_arm_y; h++)
166         api->line((void *)api, which, canvas, snapshot, canvas->w, left_y - h, -1, right_arm_y - h, 1, fold_erase);
167     }
168   else if (right_arm_y > canvas->h)
169     {
170       for (w = 0; w <= left_arm_x; w++)
171         api->line((void *)api, which, canvas, snapshot, left_arm_x - w, 0, right_x - w, canvas->h + 1, 1, fold_erase);
172     }
173   else
174     for (w = 0; w <= min(left_arm_x, right_arm_y); w++) // The -1 values are because api->line
175       api->line((void *)api, which, canvas, snapshot, left_arm_x - w, 0, -1, right_arm_y - w, 1, fold_erase);
176 
177   SDL_BlitSurface(canvas, 0, temp, 0);
178 
179   // Shadows
180   if (left_arm_x > canvas->w)
181     {
182       for (fold_shadow_value = 0; fold_shadow_value < 40; fold_shadow_value += 1)
183         api->line((void *)api, which, canvas, temp, canvas->w, left_y - fold_shadow_value, 0,
184                   right_arm_y - fold_shadow_value, 1, fold_shadow);
185 
186     }
187   else if (right_arm_y > canvas->h)
188     {
189       for (fold_shadow_value = 0; fold_shadow_value < 40; fold_shadow_value += 1)
190         api->line((void *)api, which, canvas, temp, left_arm_x - fold_shadow_value, 0, right_x - fold_shadow_value,
191                   canvas->h, 1, fold_shadow);
192 
193     }
194 
195   else
196     for (fold_shadow_value = 0; fold_shadow_value < 40; fold_shadow_value += 1)
197       api->line((void *)api, which, canvas, temp, left_arm_x - fold_shadow_value, 0, 0, right_arm_y - fold_shadow_value,
198                 1, fold_shadow);
199 
200   SDL_BlitSurface(canvas, 0, temp, 0);
201 
202   for (fold_shadow_value = 0; fold_shadow_value < 40; fold_shadow_value += 1)
203     {
204       if (fold_shadow_value * left_step_x > x || fold_shadow_value * right_step_y > y)
205         break;
206 
207       dist_x = fold_shadow_value * (right_step_x + left_step_x);
208       dist_y = fold_shadow_value * (right_step_y + left_step_y);
209       api->line((void *)api, which, canvas, temp, left_arm_x + fold_shadow_value * right_step_x,
210                 fold_shadow_value * right_step_y, fold_shadow_value * left_step_x,
211                 right_arm_y + fold_shadow_value * left_step_y, 1, fold_shadow);
212     }
213 
214   api->line((void *)api, which, canvas, snapshot, x, y, right_arm_x, right_arm_y, 1, fold_print_line);
215   api->line((void *)api, which, canvas, snapshot, x, y, left_arm_x, left_arm_y, 1, fold_print_line);
216   api->line((void *)api, which, canvas, snapshot, left_arm_x, left_arm_y, right_arm_x, right_arm_y, 1,
217             fold_print_dark_line);
218 
219 }
220 
rotate(magic_api * api,SDL_Surface * canvas,int angle)221 SDL_Surface *rotate(magic_api * api, SDL_Surface * canvas, int angle)
222 {
223   SDL_Surface *temp;
224   int x, y;
225   int a, b;
226 
227   if (angle == 180)
228     temp = SDL_CreateRGBSurface(SDL_ANYFORMAT, canvas->w, canvas->h, canvas->format->BitsPerPixel,
229                                 canvas->format->Rmask, canvas->format->Gmask, canvas->format->Bmask,
230                                 canvas->format->Amask);
231   else
232     temp = SDL_CreateRGBSurface(SDL_ANYFORMAT, canvas->h, canvas->w, canvas->format->BitsPerPixel,
233                                 canvas->format->Rmask, canvas->format->Gmask, canvas->format->Bmask,
234                                 canvas->format->Amask);
235 
236   switch (angle)
237     {
238     case 90:
239       for (x = 0; x < canvas->w; x++)
240         for (y = 0; y < canvas->h; y++)
241           {
242             translate_xy(canvas, x, y, &a, &b, 90);
243             api->putpixel(temp, a, b, api->getpixel(canvas, x, y));
244           }
245       break;
246 
247     case 180:
248       //      printf("%i, %i\n",temp,canvas);
249       for (x = 0; x < canvas->w; x++)
250         for (y = 0; y < canvas->h; y++)
251           {
252             translate_xy(canvas, x, y, &a, &b, 180);
253             api->putpixel(temp, a, b, api->getpixel(canvas, x, y));
254           }
255       break;
256 
257     case 270:
258       for (x = 0; x < canvas->w; x++)
259         for (y = 0; y < canvas->h; y++)
260           {
261             translate_xy(canvas, x, y, &a, &b, 270);
262             api->putpixel(temp, a, b, api->getpixel(canvas, x, y));
263           }
264       break;
265     }
266   return temp;
267 }
268 
translate_coords(SDL_Surface * canvas,int angle)269 void translate_coords(SDL_Surface * canvas, int angle)
270 {
271   int a, b;
272 
273   switch (angle)
274     {
275     case 90:
276       translate_xy(canvas, right_arm_x, right_arm_y, &a, &b, 90);
277       right_arm_x = a;
278       right_arm_y = b;
279       translate_xy(canvas, left_arm_x, left_arm_y, &a, &b, 90);
280       left_arm_x = a;
281       left_arm_y = b;
282 
283       break;
284     case 180:
285       right_arm_x = canvas->w - 1 - right_arm_x;
286       right_arm_y = canvas->h - 1 - right_arm_y;
287       left_arm_x = canvas->w - 1 - left_arm_x;
288       left_arm_y = canvas->h - 1 - left_arm_y;
289       break;
290     case 270:
291       translate_xy(canvas, right_arm_x, right_arm_y, &a, &b, 270);
292       right_arm_x = a;
293       right_arm_y = b;
294       translate_xy(canvas, left_arm_x, left_arm_y, &a, &b, 270);
295       left_arm_x = a;
296       left_arm_y = b;
297       break;
298     }
299 }
300 
translate_xy(SDL_Surface * canvas,int x,int y,int * a,int * b,int rotation)301 void translate_xy(SDL_Surface * canvas, int x, int y, int *a, int *b, int rotation)
302 {
303   switch (rotation)
304     {
305     case 90:
306       *a = y;
307       *b = canvas->w - 1 - x;
308       break;
309     case 180:
310       *a = canvas->w - 1 - x;
311       *b = canvas->h - 1 - y;
312       break;
313     case 270:
314       *a = canvas->h - 1 - y;
315       *b = x;
316       break;
317     }
318 }
319 
fold_release(magic_api * api,int which,SDL_Surface * canvas,SDL_Surface * snapshot,int x,int y,SDL_Rect * update_rect)320 void fold_release(magic_api * api, int which,
321                   SDL_Surface * canvas, SDL_Surface * snapshot, int x, int y, SDL_Rect * update_rect)
322 {
323   int a, b;
324   SDL_Surface *temp, *temp2;
325 
326   x = fold_x;
327   y = fold_y;
328   fold_ox = fold_oy = 0;
329   SDL_BlitSurface(snapshot, 0, canvas, 0);
330   switch (corner)
331     {
332     case 1:
333       translate_xy(canvas, x, y, &a, &b, 90);
334       translate_coords(canvas, 90);
335       temp = rotate(api, canvas, 90);
336       fold_draw(api, which, temp, snapshot, a, b, update_rect);
337       temp2 = rotate(api, temp, 270);
338       SDL_BlitSurface(temp2, 0, canvas, 0);
339       SDL_FreeSurface(temp);
340       SDL_FreeSurface(temp2);
341       break;
342 
343     case 2:
344       fold_draw(api, which, canvas, snapshot, x, y, update_rect);
345       break;
346 
347     case 3:
348       translate_xy(canvas, x, y, &a, &b, 270);
349       translate_coords(canvas, 270);
350       temp = rotate(api, canvas, 270);
351       fold_draw(api, which, temp, snapshot, a, b, update_rect);
352       temp2 = rotate(api, temp, 90);
353       SDL_BlitSurface(temp2, 0, canvas, 0);
354       SDL_FreeSurface(temp);
355       SDL_FreeSurface(temp2);
356       break;
357 
358     case 4:
359       translate_xy(canvas, x, y, &a, &b, 180);
360       translate_coords(canvas, 180);
361       temp = rotate(api, canvas, 180);
362       fold_draw(api, which, temp, snapshot, a, b, update_rect);
363       temp2 = rotate(api, temp, 180);
364       SDL_BlitSurface(temp2, 0, canvas, 0);
365       SDL_FreeSurface(temp);
366       SDL_FreeSurface(temp2);
367       break;
368     }
369 
370   update_rect->x = update_rect->y = 0;
371   update_rect->w = canvas->w;
372   update_rect->h = canvas->h;
373   api->playsound(fold_snd, (x * 255) / canvas->w, 255);
374 }
375 
fold_shutdown(magic_api * api ATTRIBUTE_UNUSED)376 void fold_shutdown(magic_api * api ATTRIBUTE_UNUSED)
377 {
378   Mix_FreeChunk(fold_snd);
379   SDL_FreeSurface(fold_surface_dst);
380   SDL_FreeSurface(fold_surface_src);
381 }
382 
383 // Interactivity functions
384 
fold_what_corner(int x,int y,SDL_Surface * canvas)385 inline Uint8 fold_what_corner(int x, int y, SDL_Surface * canvas)
386 {
387   if (x >= canvas->w / 2)
388     {
389       if (y >= canvas->h / 2)
390         return 4;
391       else
392         return 1;
393     }
394   else
395     {
396       if (y >= canvas->h / 2)
397         return 3;
398       else
399         return 2;
400     }
401 }
402 
403 
fold_print_line(void * ptr,int which ATTRIBUTE_UNUSED,SDL_Surface * canvas,SDL_Surface * last,int x,int y)404 static void fold_print_line(void *ptr, int which ATTRIBUTE_UNUSED, SDL_Surface * canvas, SDL_Surface * last,
405                             int x, int y)
406 {
407   magic_api *api = (magic_api *) ptr;
408 
409   api->putpixel(canvas, x, y, SDL_MapRGB(last->format, 222, 222, 222)); //Middle gray. Color have been set arbitrary.
410 }
411 
fold_print_dark_line(void * ptr,int which ATTRIBUTE_UNUSED,SDL_Surface * canvas,SDL_Surface * last ATTRIBUTE_UNUSED,int x,int y)412 static void fold_print_dark_line(void *ptr, int which ATTRIBUTE_UNUSED, SDL_Surface * canvas,
413                                  SDL_Surface * last ATTRIBUTE_UNUSED, int x, int y)
414 {
415   magic_api *api = (magic_api *) ptr;
416 
417   api->putpixel(canvas, x, y, SDL_MapRGB(last->format, 90, 90, 90));    //It should not look too black nor too white with shadowed colors.
418 }
419 
fold_erase(void * ptr,int which ATTRIBUTE_UNUSED,SDL_Surface * canvas,SDL_Surface * last ATTRIBUTE_UNUSED,int x,int y)420 static void fold_erase(void *ptr, int which ATTRIBUTE_UNUSED, SDL_Surface * canvas, SDL_Surface * last ATTRIBUTE_UNUSED,
421                        int x, int y)
422 {
423   magic_api *api = (magic_api *) ptr;
424 
425   api->putpixel(canvas, x, y, SDL_MapRGB(canvas->format, fold_r, fold_g, fold_b));
426 }
427 
fold_click(magic_api * ptr,int which,int mode ATTRIBUTE_UNUSED,SDL_Surface * canvas,SDL_Surface * snapshot,int x,int y,SDL_Rect * update_rect)428 void fold_click(magic_api * ptr, int which, int mode ATTRIBUTE_UNUSED,
429                 SDL_Surface * canvas, SDL_Surface * snapshot, int x, int y, SDL_Rect * update_rect)
430 {
431   magic_api *api = (magic_api *) ptr;
432 
433   corner = fold_what_corner(x, y, snapshot);
434 
435   switch (corner)
436     {
437     case 1:
438       fold_ox = canvas->w - 1;
439       fold_oy = 0;
440       break;
441     case 2:
442       fold_ox = fold_oy = 0;
443       break;
444     case 3:
445       fold_ox = 0;
446       fold_oy = canvas->h - 1;
447       break;
448     case 4:
449       fold_ox = canvas->w - 1;
450       fold_oy = canvas->h - 1;
451       break;
452     }
453 
454   fold_drag(api, which, canvas, snapshot, x, y, x, y, update_rect);
455 }
456 
fold_preview(magic_api * api,int which,SDL_Surface * canvas,SDL_Surface * snapshot,int ox ATTRIBUTE_UNUSED,int oy ATTRIBUTE_UNUSED,int x,int y,SDL_Rect * update_rect)457 void fold_preview(magic_api * api, int which, SDL_Surface * canvas,
458                   SDL_Surface * snapshot, int ox ATTRIBUTE_UNUSED, int oy ATTRIBUTE_UNUSED, int x, int y,
459                   SDL_Rect * update_rect)
460 {
461   int middle_point_x;
462   int middle_point_y;
463 
464   fold_x = x;
465   fold_y = y;
466   SDL_BlitSurface(snapshot, 0, canvas, 0);
467 
468   middle_point_x = (fold_ox + x) / 2;
469   middle_point_y = (fold_oy + y) / 2;
470 
471   switch (corner)
472     {
473     case 1:                    //Right Upper
474       right_arm_x = fold_ox - (fold_ox - middle_point_x) - middle_point_y * middle_point_y / (fold_ox - middle_point_x);
475       right_arm_y = fold_oy;
476 
477       left_arm_x = fold_ox;
478       left_arm_y =
479         fold_oy - (fold_oy - middle_point_y) - (fold_ox - middle_point_x) * (fold_ox - middle_point_x) / (fold_oy -
480                                                                                                           middle_point_y);
481       break;
482 
483     case 2:                    //LU
484       right_arm_x = fold_ox;
485       right_arm_y = middle_point_y + middle_point_x * middle_point_x / middle_point_y;
486 
487       left_arm_x = middle_point_x + middle_point_y * middle_point_y / middle_point_x;
488       left_arm_y = fold_oy;
489       break;
490 
491     case 3:                    //LL
492       right_arm_x = middle_point_x + (fold_oy - middle_point_y) * (fold_oy - middle_point_y) / middle_point_x;
493       right_arm_y = fold_oy;
494 
495       left_arm_x = fold_ox;
496       left_arm_y =
497         fold_oy - (fold_oy - middle_point_y) - (fold_ox - middle_point_x) * (fold_ox - middle_point_x) / (fold_oy -
498                                                                                                           middle_point_y);
499       break;
500 
501     case 4:                    //RL
502       right_arm_x = fold_ox;
503       right_arm_y =
504         fold_oy - (fold_oy - middle_point_y) - (fold_ox - middle_point_x) * (fold_ox - middle_point_x) / (fold_oy -
505                                                                                                           middle_point_y);
506 
507       left_arm_x =
508         fold_ox - (fold_ox - middle_point_x) - (fold_oy - middle_point_y) * (fold_oy - middle_point_y) / (fold_ox -
509                                                                                                           middle_point_x);
510       left_arm_y = fold_oy;
511       break;
512     }
513 
514   api->line((void *)api, which, canvas, snapshot, x, y, right_arm_x, right_arm_y, 1, fold_print_line);
515   api->line((void *)api, which, canvas, snapshot, x, y, left_arm_x, left_arm_y, 1, fold_print_line);
516   api->line((void *)api, which, canvas, snapshot, left_arm_x, left_arm_y, right_arm_x, right_arm_y, 1, fold_print_line);
517 
518   update_rect->x = update_rect->y = 0;
519   update_rect->w = canvas->w;
520   update_rect->h = canvas->h;
521 }
522 
fold_drag(magic_api * api,int which,SDL_Surface * canvas,SDL_Surface * snapshot,int ox,int oy,int x,int y,SDL_Rect * update_rect)523 void fold_drag(magic_api * api, int which, SDL_Surface * canvas,
524                SDL_Surface * snapshot, int ox, int oy, int x, int y, SDL_Rect * update_rect)
525 {
526   // Avoid division by zero when calculating the preview
527   x = clamp(2, x, canvas->w - 2);
528   y = clamp(2, y, canvas->h - 2);
529   fold_preview(api, which, canvas, snapshot, ox, oy, x, y, update_rect);
530 }
531 
fold_switchin(magic_api * api ATTRIBUTE_UNUSED,int which ATTRIBUTE_UNUSED,int mode ATTRIBUTE_UNUSED,SDL_Surface * canvas ATTRIBUTE_UNUSED)532 void fold_switchin(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED, int mode ATTRIBUTE_UNUSED,
533                    SDL_Surface * canvas ATTRIBUTE_UNUSED)
534 {
535 }
536 
fold_switchout(magic_api * api ATTRIBUTE_UNUSED,int which ATTRIBUTE_UNUSED,int mode ATTRIBUTE_UNUSED,SDL_Surface * canvas ATTRIBUTE_UNUSED)537 void fold_switchout(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED, int mode ATTRIBUTE_UNUSED,
538                     SDL_Surface * canvas ATTRIBUTE_UNUSED)
539 {
540 }
541 
fold_modes(magic_api * api ATTRIBUTE_UNUSED,int which ATTRIBUTE_UNUSED)542 int fold_modes(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED)
543 {
544   return (MODE_PAINT_WITH_PREVIEW);
545 }
546