static void
gimp_brush_generated_transform_size (GimpBrush *gbrush,
gdouble scale,
gdouble aspect_ratio,
gdouble angle,
gint *width,
gint *height)
{
GimpBrushGenerated *brush = GIMP_BRUSH_GENERATED (gbrush);
gdouble ratio;
ratio = fabs (aspect_ratio) * 19.0 / 20.0 + 1.0;
ratio = MIN (ratio, 20);
/* Since generated brushes are symmetric they don't have aspect
* ratios < 1.0. it's the same as rotating by 90 degrees and 1 /
* ratio, so we fix the input for this case.
*/
if (aspect_ratio < 0.0)
angle = angle + 0.25;
angle *= 360;
if (angle < 0.0)
angle = -1.0 * fmod (angle, 180.0);
else if (angle > 180.0)
angle = fmod (angle, 180.0);
gimp_brush_generated_get_size (brush,
brush->shape,
brush->radius * scale,
brush->spikes,
brush->hardness,
ratio,
angle,
width, height,
NULL, NULL, NULL, NULL);
}
static void
gimp_brush_generated_transform_size (GimpBrush *gbrush,
gdouble scale,
gdouble aspect_ratio,
gdouble angle,
gint *width,
gint *height)
{
GimpBrushGenerated *brush = GIMP_BRUSH_GENERATED (gbrush);
gdouble ratio;
if (aspect_ratio == 0.0)
{
ratio = brush->aspect_ratio;
}
else
{
ratio = MIN (fabs (aspect_ratio) + 1, 20);
/* Since generated brushes are symmetric the dont have input
* for aspect ratios < 1.0. its same as rotate by 90 degrees and
* 1 / ratio. So we fix the input up for this case. */
if (aspect_ratio < 0.0)
{
angle = angle + 0.25;
}
}
gimp_brush_generated_get_size (brush,
brush->shape,
brush->radius * scale,
brush->spikes,
brush->hardness,
ratio,
(brush->angle + 360 * angle),
width, height,
NULL, NULL, NULL, NULL);
}
static GimpTempBuf *
gimp_brush_generated_calc (GimpBrushGenerated *brush,
GimpBrushGeneratedShape shape,
gfloat radius,
gint spikes,
gfloat hardness,
gfloat aspect_ratio,
gfloat angle,
GimpVector2 *xaxis,
GimpVector2 *yaxis)
{
guchar *centerp;
guchar *lookup;
guchar a;
gint x, y;
gdouble c, s, cs, ss;
GimpVector2 x_axis;
GimpVector2 y_axis;
GimpTempBuf *mask;
gint width;
gint height;
gint half_width;
gint half_height;
gimp_brush_generated_get_size (brush,
shape,
radius,
spikes,
hardness,
aspect_ratio,
angle,
&width, &height,
&s, &c, &x_axis, &y_axis);
mask = gimp_temp_buf_new (width, height,
babl_format ("Y u8"));
half_width = width / 2;
half_height = height / 2;
centerp = gimp_temp_buf_get_data (mask) +
half_height * width + half_width;
lookup = gimp_brush_generated_calc_lut (radius, hardness);
cs = cos (- 2 * G_PI / spikes);
ss = sin (- 2 * G_PI / spikes);
/* for an even number of spikes compute one half and mirror it */
for (y = ((spikes % 2) ? -half_height : 0); y <= half_height; y++)
{
for (x = -half_width; x <= half_width; x++)
{
gdouble d = 0;
gdouble tx = c * x - s * y;
gdouble ty = fabs (s * x + c * y);
if (spikes > 2)
{
gdouble angle = atan2 (ty, tx);
while (angle > G_PI / spikes)
{
gdouble sx = tx;
gdouble sy = ty;
tx = cs * sx - ss * sy;
ty = ss * sx + cs * sy;
angle -= 2 * G_PI / spikes;
}
}
ty *= aspect_ratio;
switch (shape)
{
case GIMP_BRUSH_GENERATED_CIRCLE:
d = sqrt (SQR (tx) + SQR (ty));
break;
case GIMP_BRUSH_GENERATED_SQUARE:
d = MAX (fabs (tx), fabs (ty));
break;
case GIMP_BRUSH_GENERATED_DIAMOND:
d = fabs (tx) + fabs (ty);
break;
}
if (d < radius + 1)
a = lookup[(gint) RINT (d * OVERSAMPLING)];
else
a = 0;
centerp[y * width + x] = a;
if (spikes % 2 == 0)
centerp[-1 * y * width - x] = a;
}
}
g_free (lookup);
if (xaxis)
*xaxis = x_axis;
if (yaxis)
*yaxis = y_axis;
return mask;
}
