From af8fd5b8a115a4b3386eecf04a1ef37d1d95ddcb Mon Sep 17 00:00:00 2001
From: Bill Kendrick <nbs@sonic.net>
Date: Tue, 16 Nov 2021 00:13:44 -0800
Subject: [PATCH] Attempts to improve rotated brushes

 * Rotating brush angle is now a double, not an int
 * Don't draw once on click; require some motion
   (does not affect directional brushes, which include
   a "no movement" shape in the middle of the brush bitmap)
---
 src/tuxpaint.c | 34 ++++++++++++++++++++--------------
 1 file changed, 20 insertions(+), 14 deletions(-)

diff --git a/src/tuxpaint.c b/src/tuxpaint.c
index 64ecfde21..d2ad15675 100644
--- a/src/tuxpaint.c
+++ b/src/tuxpaint.c
@@ -1967,7 +1967,7 @@ SDL_Joystick *joystick;
 
 static void mainloop(void);
 static void brush_draw(int x1, int y1, int x2, int y2, int update);
-static void blit_brush(int x, int y, int direction, int rotation, int * w, int * h);
+static void blit_brush(int x, int y, int direction, double rotation, int * w, int * h);
 static void stamp_draw(int x, int y);
 static void rec_undo_buffer(void);
 
@@ -5995,8 +5995,9 @@ static void brush_draw(int x1, int y1, int x2, int y2, int update)
 {
   int dx, dy, y, frame_w, w, h, sz;
   int orig_x1, orig_y1, orig_x2, orig_y2, tmp;
-  int direction, r;
+  int direction;
   float m, b;
+  double r;
 
   orig_x1 = x1;
   orig_y1 = y1;
@@ -6017,22 +6018,22 @@ static void brush_draw(int x1, int y1, int x2, int y2, int update)
 
 
   direction = BRUSH_DIRECTION_NONE;
-  r = 0;
+  r = -1.0;
   if (brushes_directional[cur_brush] || brushes_rotate[cur_brush])
     {
       r = brush_rotation(x1, y1, x2, y2);
 
       if (brushes_directional[cur_brush])
         {
-          r = r + 22;
-          if (r < 0)
-            r = r + 360;
+          r = r + 22.0;
+          if (r < 0.0)
+            r = r + 360.0;
           if (x1 != x2 || y1 != y2)
-            direction = (r / 45);
+            direction = (r / 45.0);
         }
       else
         {
-          r = 270 - r;
+          r = 270.0 - r;
         }
     }
 
@@ -6107,13 +6108,18 @@ static void brush_draw(int x1, int y1, int x2, int y2, int update)
 
 
 /**
- * Reset the brush counter, such that the next
- * attempt to draw something is guaranteed to
- * do so, regardless of the brushe's spacing.
+ * Reset the brush counter, such that the next attempt to draw something
+ * is either (a) guaranteed to do so, regardless of the brush's spacing
+ * (for non-rotational brushes), or (b) requires the user to have moved
+ * far enough to get a good idea of the angle they're drawing
+ * (for rotational brushes).
  */
 void reset_brush_counter(void)
 {
-  brush_counter = 999;
+  if (img_cur_brush_rotate)
+    brush_counter = 0;
+  else
+    brush_counter = 999;
 }
 
 
@@ -6129,7 +6135,7 @@ void reset_brush_counter(void)
  * @param direction BRUSH_DIRECTION_... being drawn (for compass direction brushes)
  * @param rotation angle being drawn (for brushes which may rotate at any angle (0-360 degrees))
  */
-static void blit_brush(int x, int y, int direction, int rotation, int * w, int * h)
+static void blit_brush(int x, int y, int direction, double rotation, int * w, int * h)
 {
   SDL_Rect src, dest;
 
@@ -6202,7 +6208,7 @@ static void blit_brush(int x, int y, int direction, int rotation, int * w, int *
       src.w = img_cur_brush_w;
       src.h = img_cur_brush_h;
 
-      if (img_cur_brush_rotate)
+      if (img_cur_brush_rotate && rotation != -1.0 /* only if we're moving */)
         {
           SDL_Surface * rotated_brush;