void
render (gint32 image_ID,
GimpDrawable *drawable,
PlugInVals *vals,
PlugInImageVals *image_vals,
PlugInDrawableVals *drawable_vals)
{
double angle = gimp_find_skew(drawable); // in radians
DEBUGPRINT("deskew: angle=%.2f\n",
57.295779513082320876798154814105*angle);
if (fabs(angle) < deskew_threshold) {
// nothing to do; already straightened.
return;
}
gimp_context_push ();
gimp_context_set_interpolation (GIMP_INTERPOLATION_CUBIC);
gimp_context_set_transform_resize (GIMP_TRANSFORM_RESIZE_ADJUST);
drawable->drawable_id =
gimp_item_transform_rotate(drawable->drawable_id,
angle,
TRUE, // auto_center
-1, -1 // center_x, center_y
);
gimp_context_pop ();
}
/* -----------------------------------
* p_exact_align_drawable
* -----------------------------------
* 4-point alignment including necessary scale and rotate transformation
* to match 2 pairs of corresponding coordonates.
*/
static gint32
p_exact_align_drawable(gint32 activeDrawableId, AlingCoords *alingCoords)
{
gdouble px1, py1, px2, py2;
gdouble px3, py3, px4, py4;
gdouble dx1, dy1, dx2, dy2;
gdouble angle1Rad, angle2Rad, angleRad;
gdouble len1, len2;
gdouble scaleXY;
gint32 transformedDrawableId;
px1 = alingCoords->startCoords.px;
py1 = alingCoords->startCoords.py;
px2 = alingCoords->startCoords2.px;
py2 = alingCoords->startCoords2.py;
px3 = alingCoords->currCoords.px;
py3 = alingCoords->currCoords.py;
px4 = alingCoords->currCoords2.px;
py4 = alingCoords->currCoords2.py;
dx1 = px2 - px1;
dy1 = py2 - py1;
dx2 = px4 - px3;
dy2 = py4 - py3;
/* the angle between the two lines. i.e., the angle layer2 must be clockwise rotated
* in order to overlap with initial start layer1
*/
angle1Rad = 0;
angle2Rad = 0;
if (dx1 != 0.0)
{
angle1Rad = atan(dy1 / dx1);
}
if (dx2 != 0.0)
{
angle2Rad = atan(dy2 / dx2);
}
angleRad = angle1Rad - angle2Rad;
/* the scale factors current layer must be mulitplied by,
* in order to fit onto reference start layer.
* this is simply the ratio of the two line lenths from the path we created with the 4 points
*/
len1 = sqrt((dx1 * dx1) + (dy1 * dy1));
len2 = sqrt((dx2 * dx2) + (dy2 * dy2));
scaleXY = 1.0;
if ((len1 != len2)
&& (len2 != 0.0))
{
scaleXY = len1 / len2;
}
gimp_context_set_defaults();
gimp_context_set_transform_resize(GIMP_TRANSFORM_RESIZE_ADJUST); /* do NOT clip */
gimp_context_set_transform_direction(GIMP_TRANSFORM_FORWARD);
transformedDrawableId = gimp_item_transform_2d(activeDrawableId
, px3
, py3
, scaleXY
, scaleXY
, angleRad
, px1
, py1
);
if(gap_debug)
{
printf("p_exact_align_drawable: activeDrawableId:%d transformedDrawableId:%d\n"
" p1: %f %f\n"
" p2: %f %f\n"
" p3: %f %f\n"
" p4: %f %f\n"
" scale:%f angleRad:%f (degree:%f)\n"
,(int)activeDrawableId
,(int)transformedDrawableId
,(float)px1
,(float)py1
,(float)px2
,(float)py2
,(float)px3
,(float)py3
,(float)px4
,(float)py4
,(float)scaleXY
,(float)angleRad
,(float)(angleRad * 180.0) / G_PI
);
}
return (transformedDrawableId);
} /* end p_exact_align_drawable */
