WIP Specular Reflection magic tool

docs/CHANGES.txt

@@ -7,6 +7,16 @@ Various contributors (see below, and AUTHORS.txt)
 https://tuxpaint.org/
 
 2024.February.28 (0.9.33)
+  * New Magic Tools:
+    ----------------
+    * WIP Specular Reflection: Draws a slightly blurred, wavy, and
+      faded reflection of the opposite half of the drawing.
+      Bill Kendrick <bill@newbreedsoftware.com>
+      + WIP Needs docs
+      + WIP Add to new features lists
+      + WIP Needs icon
+      + WIP Needs sound effect
+
   * Other Improvements:
     -------------------
     * Make screen refresh more snappy on macOS.

magic/src/specular.c

@@ -0,0 +1,229 @@
+/* specular.c
+
+   A specular reflection Magic tool for Tux Paint
+   by Bill Kendrick <bill@newbreedsoftware.com>
+
+   Last updated: February 28, 2024
+*/
+
+
+/* Inclusion of header files */
+/* ---------------------------------------------------------------------- */
+
+#include <stdio.h>
+#include <string.h>
+#include <libintl.h>
+
+#include "tp_magic_api.h"
+#include "SDL_image.h"
+#include "SDL_mixer.h"
+
+/* Our global variables: */
+/* ---------------------------------------------------------------------- */
+
+/* Sound effects: */
+Mix_Chunk *snd_effect;
+
+/* The size the user has selected in Tux Paint: */
+Uint8 specular_size = 32;
+
+
+void specular_drag(magic_api * api, int which, SDL_Surface * canvas,
+  SDL_Surface * snapshot, int old_x, int old_y, int x, int y,
+  SDL_Rect * update_rect);
+
+void specular_line_callback(void *pointer, int which, SDL_Surface * canvas,
+  SDL_Surface * snapshot, int x, int y);
+
+
+Uint32 specular_api_version(void)
+{
+  return (TP_MAGIC_API_VERSION);
+}
+
+int specular_init(magic_api * api, Uint8 disabled_features, Uint8 complexity_level)
+{
+  int i;
+  char filename[1024];
+
+  snprintf(filename, sizeof(filename), "%ssounds/magic/%s", api->data_directory,
+           "reflection.ogg"); // FIXME
+  snd_effect = Mix_LoadWAV(filename);
+
+  return (1);
+}
+
+
+int specular_get_tool_count(magic_api * api)
+{
+  return (1);
+}
+
+SDL_Surface *specular_get_icon(magic_api * api, int which)
+{
+  char filename[1024];
+
+  snprintf(filename, sizeof(filename), "%simages/magic/%s",
+           api->data_directory, "reflection.png"); // FIXME
+
+  return (IMG_Load(filename));
+}
+
+
+char *specular_get_name(magic_api * api, int which)
+{
+  return strdup(gettext("Specular Reflection"));
+}
+
+
+int specular_get_group(magic_api * api, int which)
+{
+  return MAGIC_TYPE_PAINTING;
+}
+
+
+int specular_get_order(int which)
+{
+  return 1710;
+}
+
+
+char *specular_get_description(magic_api * api, int which, int mode)
+{
+  return strdup(gettext("Click and drag on the bottom half of your picture to draw a specular reflection — like a puddle, pond, or lake — that mirrors the top half of your picture."));
+}
+
+
+int specular_requires_colors(magic_api * api, int which)
+{
+  return 0;
+}
+
+
+int specular_modes(magic_api * api, int which)
+{
+  return MODE_PAINT;
+}
+
+
+Uint8 specular_accepted_sizes(magic_api * api, int which, int mode)
+{
+  return 4;
+}
+
+
+Uint8 specular_default_size(magic_api * api, int which, int mode)
+{
+  return 2;
+}
+
+
+void specular_shutdown(magic_api * api)
+{
+  if (snd_effect != NULL) {
+    Mix_FreeChunk(snd_effect);
+  }
+}
+
+
+void
+specular_click(magic_api * api, int which, int mode,
+              SDL_Surface * canvas, SDL_Surface * snapshot, int x, int y,
+              SDL_Rect * update_rect)
+{
+  specular_drag(api, which, canvas, snapshot, x, y, x, y, update_rect);
+}
+
+
+void
+specular_drag(magic_api * api, int which,
+             SDL_Surface * canvas, SDL_Surface * snapshot,
+             int old_x, int old_y, int x, int y,
+             SDL_Rect * update_rect)
+{
+  SDL_LockSurface(snapshot);
+  SDL_LockSurface(canvas);
+
+  api->line((void *) api, which, canvas, snapshot,
+            old_x, old_y, x, y, 1,
+            specular_line_callback);
+
+  SDL_UnlockSurface(canvas);
+  SDL_UnlockSurface(snapshot);
+
+  if (old_x > x)
+  {
+    int temp = old_x;
+
+    old_x = x;
+    x = temp;
+  }
+  if (old_y > y)
+  {
+    int temp = old_y;
+
+    old_y = y;
+    y = temp;
+  }
+
+  update_rect->x = old_x - specular_size;
+  update_rect->y = old_y - specular_size;
+  update_rect->w = (x + specular_size) - update_rect->x + 1;
+  update_rect->h = (y + specular_size) - update_rect->y + 1;
+
+  api->playsound(snd_effect, (x * 255) / canvas->w, 255);
+}
+
+void
+specular_release(magic_api * api, int which,
+                SDL_Surface * canvas, SDL_Surface * snapshot, int x, int y,
+                SDL_Rect * update_rect)
+{
+}
+
+void specular_set_color(magic_api * api, int which, SDL_Surface * canvas, SDL_Surface * snapshot, Uint8 r, Uint8 g, Uint8 b, SDL_Rect * update_rect)
+{
+}
+
+void specular_set_size(magic_api * api, int which, int mode, SDL_Surface * canvas, SDL_Surface * snapshot, Uint8 size, SDL_Rect * update_rect)
+{
+  specular_size = size * 16;
+}
+
+
+void specular_line_callback(void *pointer, int which, SDL_Surface * canvas,
+  SDL_Surface * snapshot, int x, int y)
+{
+  magic_api *api = (magic_api *) pointer;
+  int xx, yy;
+  Uint8 r, g, b, r1, g1, b1, r2, g2, b2, fade;
+
+  for (yy = -specular_size / 16; yy < specular_size / 16; yy++)
+  {
+    for (xx = -specular_size; xx < specular_size; xx++)
+    {
+      if (api->in_circle(xx, yy * 16, specular_size))
+      {
+        SDL_GetRGB(api->getpixel(snapshot, x + xx + sin((y + yy) / 4) * 4, snapshot->h - y - yy), snapshot->format, &r1, &g1, &b1);
+        SDL_GetRGB(api->getpixel(snapshot, x + xx + sin((y + yy) / 4) * 4 + 1, snapshot->h - y - yy), snapshot->format, &r2, &g2, &b2);
+
+        fade = (((y + yy) * 255) / canvas->h);
+        r = (((r1 + r2) * 2) + fade) / 5;
+        g = (((g1 + g2) * 2) + fade) / 5;
+        b = (((b1 + b2) * 2) + fade) / 5;
+
+        api->putpixel(canvas, x + xx, y + yy, SDL_MapRGB(canvas->format, r, g, b));
+      }
+    }
+  }
+}
+
+void specular_switchin(magic_api * api, int which, int mode,
+                      SDL_Surface * canvas)
+{
+}
+
+void specular_switchout(magic_api * api, int which, int mode,
+                       SDL_Surface * canvas)
+{
+}