New Magic tool: Color Sep. (aka 3D Glasses)

docs/AUTHORS.txt

@@ -6,7 +6,7 @@ Copyright (c) 2002-2023
 Various contributors (see below, and CHANGES.txt)
 https://tuxpaint.org/
 
-June 17, 2002 - February 7, 2023
+June 17, 2002 - February 21, 2023
 
 * Design and Coding:
 
@@ -137,6 +137,12 @@ June 17, 2002 - February 7, 2023
   (https://freesound.org/people/kentnelson64/sounds/647221/)
   Creative Commons 0 license by "kentnelson64"
 
+  Color Sep. magic tool
+  by Bill Kendrick <bill@newbreedsoftware.com>
+  Color Sep. sound effect: "Sci-Fi Sensors"
+  (https://freesound.org/people/Zarkonnen/sounds/168885/)
+  Creative Commons 0 license by "Zarkonnen"
+
   Mouse accessibility code and keyboard access
   Ankit Choudary <ankit.goaldecided@gmail.com>, as part of GSOC 2010,
   with integration and fixes by Pere Pujal i Carabantes <pere@fornol.no-ip.org>

docs/CHANGES.txt

@@ -7,7 +7,7 @@ Various contributors (see below, and AUTHORS.txt)
 https://tuxpaint.org/
 
 
-2023.February.19 (0.9.29)
+2023.February.21 (0.9.29)
   * Improvements to "Stamp" tool:
     -----------------------------
     * Stamps may now be rotated.
@@ -48,6 +48,12 @@ https://tuxpaint.org/
       (Sound effected licensed as Creative Commons 0 (CC0 1.0)
       by https://freesound.org/people/kentnelson64/)
 
+    * "Color Sep." (color separation) - Separate the colors of the
+      image, e.g. Red vs Cyan, as in anaglyphic "3D glasses" images.
+      Bill Kendrick <bill@newbreedsoftware.com>
+      (Sound effected licensed as Creative Commons 0 (CC0 1.0)
+      by https://freesound.org/people/Zarkonnen/)
+
     * [WIP] "Rivulet"; apply rivulets of water to the canvas
       - needs better icon
       - needs sound effect

magic/src/colorsep.c

@@ -0,0 +1,218 @@
+/* colorsep.c
+
+   Color separation effect (a la red/cyan aka red/blue 3D glasses).
+   Bill Kendrick
+
+   Last updated: February 21, 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"
+
+enum {
+  COLORSEP_MODE_RED_CYAN,
+  COLORSEP_MODE_GREEN_PURPLE,
+  COLORSEP_MODE_BLUE_YELLOW
+};
+
+Mix_Chunk *snd_effect = NULL;
+int colorsep_click_x, colorsep_click_y;
+int colorsep_mode = COLORSEP_MODE_RED_CYAN;
+
+Uint32 colorsep_api_version(void);
+int colorsep_init(magic_api * api);
+int colorsep_get_tool_count(magic_api * api);
+SDL_Surface *colorsep_get_icon(magic_api * api, int which);
+char *colorsep_get_name(magic_api * api, int which);
+int colorsep_get_group(magic_api * api, int which);
+char *colorsep_get_description(magic_api * api, int which, int mode);
+int colorsep_requires_colors(magic_api * api, int which);
+int colorsep_modes(magic_api * api, int which);
+void colorsep_shutdown(magic_api * api);
+void colorsep_click(magic_api * api, int which, int mode,
+                     SDL_Surface * canvas, SDL_Surface * snapshot, int x,
+                     int y, SDL_Rect * update_rect);
+void colorsep_set_color(magic_api * api, int which, SDL_Surface * canvas,
+                    SDL_Surface * last, Uint8 r, Uint8 g, Uint8 b, SDL_Rect * update_rect);
+void colorsep_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 colorsep_release(magic_api * api, int which, SDL_Surface * canvas,
+                       SDL_Surface * snapshot, int x, int y,
+                       SDL_Rect * update_rect);
+void colorsep_switchin(magic_api * api, int which, int mode,
+                        SDL_Surface * canvas);
+void colorsep_switchout(magic_api * api, int which, int mode,
+                         SDL_Surface * canvas);
+
+
+Uint32 colorsep_api_version(void)
+{
+  return (TP_MAGIC_API_VERSION);
+}
+
+int colorsep_init(magic_api * api)
+{
+  char fname[1024];
+
+  snprintf(fname, sizeof(fname), "%ssounds/magic/colorsep.ogg",
+           api->data_directory);
+  snd_effect = Mix_LoadWAV(fname);
+
+  return (1);
+}
+
+int colorsep_get_tool_count(magic_api * api ATTRIBUTE_UNUSED)
+{
+  return (1);
+}
+
+
+SDL_Surface *colorsep_get_icon(magic_api * api, int which ATTRIBUTE_UNUSED)
+{
+  char fname[1024];
+
+  snprintf(fname, sizeof(fname), "%simages/magic/colorsep.png",
+           api->data_directory);
+
+  return (IMG_Load(fname));
+}
+
+char *colorsep_get_name(magic_api * api ATTRIBUTE_UNUSED,
+                         int which ATTRIBUTE_UNUSED)
+{
+  return strdup(gettext("Color Sep."));
+}
+
+int colorsep_get_group(magic_api * api ATTRIBUTE_UNUSED,
+                        int which ATTRIBUTE_UNUSED)
+{
+  return MAGIC_TYPE_COLOR_FILTERS;
+}
+
+char *colorsep_get_description(magic_api * api ATTRIBUTE_UNUSED,
+                                int which ATTRIBUTE_UNUSED, int mode ATTRIBUTE_UNUSED)
+{
+  return strdup(gettext("Click and drag to separate your picture's colors (based on your color choice: red from cyan, green from purple, or blue from yellow)."));
+}
+
+int colorsep_requires_colors(magic_api * api ATTRIBUTE_UNUSED,
+                              int which ATTRIBUTE_UNUSED)
+{
+  return 1;
+}
+
+int colorsep_modes(magic_api * api ATTRIBUTE_UNUSED,
+                    int which ATTRIBUTE_UNUSED)
+{
+  return MODE_PAINT;
+}
+
+void colorsep_shutdown(magic_api * api ATTRIBUTE_UNUSED)
+{
+  if (snd_effect != NULL)
+    Mix_FreeChunk(snd_effect);
+}
+
+void
+colorsep_click(magic_api * api, int which, int mode ATTRIBUTE_UNUSED,
+                SDL_Surface * canvas, SDL_Surface * snapshot, int x, int y,
+                SDL_Rect * update_rect)
+{
+  if (snd_effect != NULL)
+    api->stopsound();
+
+  /* (Start off as if they clicked off to the side a little, so that
+   * quick click+release will split the image bit by bit */
+  colorsep_click_x = x;
+  colorsep_click_y = y;
+  colorsep_drag(api, which, canvas, snapshot, x, y, x - 10, y, update_rect);
+}
+
+
+void
+colorsep_drag(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED, SDL_Surface * canvas,
+              SDL_Surface * snapshot, int ox ATTRIBUTE_UNUSED, int oy ATTRIBUTE_UNUSED,
+              int x, int y, SDL_Rect * update_rect)
+{
+  int xx, yy, offset_x, offset_y;
+  Uint8 r1, g1, b1, r2, g2, b2;
+
+  offset_x = colorsep_click_x - x;
+  offset_y = colorsep_click_y - y;
+
+  api->playsound(snd_effect, (((-offset_x * 255) / canvas->w) + 128), 255);
+
+  for (yy = 0; yy < canvas->h; yy++) {
+    for (xx = 0; xx < canvas->w; xx++) {
+      SDL_GetRGB(api->getpixel(snapshot, xx + offset_x / 2, yy + offset_y / 2), snapshot->format, &r1, &g1, &b1);
+      SDL_GetRGB(api->getpixel(snapshot, xx - offset_x / 2, yy - offset_y / 2), snapshot->format, &r2, &g2, &b2);
+
+      if (colorsep_mode == COLORSEP_MODE_RED_CYAN) {
+        api->putpixel(canvas, xx, yy, SDL_MapRGB(canvas->format, r1, g2, b2));
+      } else if (colorsep_mode == COLORSEP_MODE_GREEN_PURPLE) {
+        api->putpixel(canvas, xx, yy, SDL_MapRGB(canvas->format, r2, g1, b2));
+      } else if (colorsep_mode == COLORSEP_MODE_BLUE_YELLOW) {
+        api->putpixel(canvas, xx, yy, SDL_MapRGB(canvas->format, r2, g2, b1));
+      }
+    }
+  }
+
+  update_rect->x = 0;
+  update_rect->y = 0;
+  update_rect->w = canvas->w;
+  update_rect->h = canvas->h;
+}
+
+
+void colorsep_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 colorsep_set_color(magic_api * api ATTRIBUTE_UNUSED, int which ATTRIBUTE_UNUSED,
+                      SDL_Surface * canvas ATTRIBUTE_UNUSED,
+                      SDL_Surface * last ATTRIBUTE_UNUSED,
+                      Uint8 r, Uint8 g, Uint8 b,
+                      SDL_Rect * update_rect ATTRIBUTE_UNUSED)
+{
+  r >>= 4;
+  g >>= 4;
+  b >>= 4;
+
+  /* If the color chosen is very strong in some colors, separate it */
+  if ((r > g && r > b) || (b > r && g > r)) {
+    colorsep_mode = COLORSEP_MODE_RED_CYAN;
+  } else if ((g > r && g > b) || (r > g && b > g)) {
+    colorsep_mode = COLORSEP_MODE_GREEN_PURPLE;
+  } else if ((b > r && b > g) || (r > b && g > b)) {
+    colorsep_mode = COLORSEP_MODE_BLUE_YELLOW;
+  } else {
+    /* No winner? Default to the most comment, red/cyan */
+    colorsep_mode = COLORSEP_MODE_RED_CYAN;
+  }
+}
+
+
+void colorsep_switchin(magic_api * api ATTRIBUTE_UNUSED,
+                        int which ATTRIBUTE_UNUSED, int mode ATTRIBUTE_UNUSED,
+                        SDL_Surface * canvas ATTRIBUTE_UNUSED)
+{
+}
+
+void colorsep_switchout(magic_api * api ATTRIBUTE_UNUSED,
+                         int which ATTRIBUTE_UNUSED,
+                         int mode ATTRIBUTE_UNUSED,
+                         SDL_Surface * canvas ATTRIBUTE_UNUSED)
+{
+}