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+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * IfsCompose is a interface for creating IFS fractals by
+ * direct manipulation.
+ * Copyright (C) 1997 Owen Taylor
+ *
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <gdk/gdk.h>
+
+#include <libgimp/gimp.h>
+
+#include "ifs-compose.h"
+
+
+typedef struct
+{
+ GdkPoint point;
+ gdouble angle;
+} SortPoint;
+
+
+/* local functions */
+static void aff_element_compute_click_boundary (AffElement *elem,
+ gint num_elements,
+ gdouble *points_x,
+ gdouble *points_y);
+static guchar * create_brush (IfsComposeVals *ifsvals,
+ gint *brush_size,
+ gdouble *brush_offset);
+
+
+void
+aff2_translate (Aff2 *naff,
+ gdouble x,
+ gdouble y)
+{
+ naff->a11 = 1.0;
+ naff->a12 = 0;
+ naff->a21 = 0;
+ naff->a22 = 1.0;
+ naff->b1 = x;
+ naff->b2 = y;
+}
+
+void
+aff2_rotate (Aff2 *naff,
+ gdouble theta)
+{
+ naff->a11 = cos(theta);
+ naff->a12 = sin(theta);
+ naff->a21 = -naff->a12;
+ naff->a22 = naff->a11;
+ naff->b1 = 0;
+ naff->b2 = 0;
+}
+
+void
+aff2_scale (Aff2 *naff,
+ gdouble s,
+ gboolean flip)
+{
+ if (flip)
+ naff->a11 = -s;
+ else
+ naff->a11 = s;
+
+ naff->a12 = 0;
+ naff->a21 = 0;
+ naff->a22 = s;
+ naff->b1 = 0;
+ naff->b2 = 0;
+}
+
+/* Create a unitary transform with given x-y asymmetry and shear */
+void
+aff2_distort (Aff2 *naff,
+ gdouble asym,
+ gdouble shear)
+{
+ naff->a11 = asym;
+ naff->a22 = 1/asym;
+ naff->a12 = shear;
+ naff->a21 = 0;
+ naff->b1 = 0;
+ naff->b2 = 0;
+}
+
+/* Find a pure stretch in some direction that brings xo,yo to xn,yn */
+void
+aff2_compute_stretch (Aff2 *naff,
+ gdouble xo,
+ gdouble yo,
+ gdouble xn,
+ gdouble yn)
+{
+ gdouble denom = xo*xn + yo*yn;
+
+ if (denom == 0.0) /* singular */
+ {
+ naff->a11 = 1.0;
+ naff->a12 = 0.0;
+ naff->a21 = 0.0;
+ naff->a22 = 1.0;
+ }
+ else
+ {
+ naff->a11 = (SQR(xn) + SQR(yo)) / denom;
+ naff->a22 = (SQR(xo) + SQR(yn)) / denom;
+ naff->a12 = naff->a21 = (xn * yn - xo * yo) / denom;
+ }
+
+ naff->b1 = 0.0;
+ naff->b2 = 0.0;
+}
+
+void
+aff2_compose (Aff2 *naff,
+ Aff2 *aff1,
+ Aff2 *aff2)
+{
+ naff->a11 = aff1->a11 * aff2->a11 + aff1->a12 * aff2->a21;
+ naff->a12 = aff1->a11 * aff2->a12 + aff1->a12 * aff2->a22;
+ naff->b1 = aff1->a11 * aff2->b1 + aff1->a12 * aff2->b2 + aff1->b1;
+ naff->a21 = aff1->a21 * aff2->a11 + aff1->a22 * aff2->a21;
+ naff->a22 = aff1->a21 * aff2->a12 + aff1->a22 * aff2->a22;
+ naff->b2 = aff1->a21 * aff2->b1 + aff1->a22 * aff2->b2 + aff1->b2;
+}
+
+/* Returns the identity matrix if the original matrix was singular */
+void
+aff2_invert (Aff2 *naff,
+ Aff2 *aff)
+{
+ gdouble det = aff->a11 * aff->a22 - aff->a12 * aff->a21;
+
+ if (det==0)
+ {
+ aff2_scale (naff, 1.0, 0);
+ }
+ else
+ {
+ naff->a11 = aff->a22 / det;
+ naff->a22 = aff->a11 / det;
+ naff->a21 = - aff->a21 / det;
+ naff->a12 = - aff->a12 / det;
+ naff->b1 = - naff->a11 * aff->b1 - naff->a12 * aff->b2;
+ naff->b2 = - naff->a21 * aff->b1 - naff->a22 * aff->b2;
+ }
+}
+
+void
+aff2_apply (Aff2 *aff,
+ gdouble x,
+ gdouble y,
+ gdouble *xf,
+ gdouble *yf)
+{
+ gdouble xt = aff->a11 * x + aff->a12 * y + aff->b1;
+ gdouble yt = aff->a21 * x + aff->a22 * y + aff->b2;
+
+ *xf = xt;
+ *yf = yt;
+}
+
+/* Find the fixed point of an affine transformation
+ (Will return garbage for pure translations) */
+
+void
+aff2_fixed_point (Aff2 *aff,
+ gdouble *xf,
+ gdouble *yf)
+{
+ Aff2 t1,t2;
+
+ t1.a11 = 1 - aff->a11;
+ t1.a22 = 1 - aff->a22;
+ t1.a12 = -aff->a12;
+ t1.a21 = -aff->a21;
+ t1.b1 = 0;
+ t1.b2 = 0;
+
+ aff2_invert (&t2, &t1);
+ aff2_apply (&t2, aff->b1, aff->b2, xf, yf);
+}
+
+void
+aff3_apply (Aff3 *t,
+ gdouble x,
+ gdouble y,
+ gdouble z,
+ gdouble *xf,
+ gdouble *yf,
+ gdouble *zf)
+{
+ gdouble xt = (t->vals[0][0] * x +
+ t->vals[0][1] * y +
+ t->vals[0][2] * z + t->vals[0][3]);
+ gdouble yt = (t->vals[1][0] * x +
+ t->vals[1][1] * y +
+ t->vals[1][2] * z + t->vals[1][3]);
+ gdouble zt = (t->vals[2][0] * x +
+ t->vals[2][1] * y +
+ t->vals[2][2] * z + t->vals[2][3]);
+
+ *xf = xt;
+ *yf = yt;
+ *zf = zt;
+}
+
+static int
+ipolygon_sort_func (const void *a,
+ const void *b)
+{
+ if (((SortPoint *)a)->angle < ((SortPoint *)b)->angle)
+ return -1;
+ else if (((SortPoint *)a)->angle > ((SortPoint *)b)->angle)
+ return 1;
+ else
+ return 0;
+}
+
+/* Return a newly-allocated polygon which is the convex hull
+ of the given polygon.
+
+ Uses the Graham scan. see
+ http://www.cs.curtin.edu.au/units/cg201/notes/node77.html
+
+ for a description
+*/
+
+IPolygon *
+ipolygon_convex_hull (IPolygon *poly)
+{
+ gint num_new = poly->npoints;
+ GdkPoint *new_points = g_new (GdkPoint, num_new);
+ SortPoint *sort_points = g_new (SortPoint, num_new);
+ IPolygon *new_poly = g_new (IPolygon, 1);
+
+ gint i, j;
+ gint x1, x2, y1, y2;
+ gint lowest;
+ GdkPoint lowest_pt;
+
+ new_poly->points = new_points;
+ if (num_new <= 3)
+ {
+ memcpy (new_points, poly->points, num_new * sizeof (GdkPoint));
+ new_poly->npoints = num_new;
+ g_free (sort_points);
+ return new_poly;
+ }
+
+ /* scan for the lowest point */
+ lowest_pt = poly->points[0];
+ lowest = 0;
+
+ for (i = 1; i < num_new; i++)
+ if (poly->points[i].y < lowest_pt.y)
+ {
+ lowest_pt = poly->points[i];
+ lowest = i;
+ }
+
+ /* sort by angle from lowest point */
+
+ for (i = 0, j = 0; i < num_new; i++, j++)
+ {
+ if (i==lowest)
+ j--;
+ else
+ {
+ gdouble dy = poly->points[i].y - lowest_pt.y;
+ gdouble dx = poly->points[i].x - lowest_pt.x;
+
+ if (dy == 0 && dx == 0)
+ {
+ j--;
+ num_new--;
+ continue;
+ }
+ sort_points[j].point = poly->points[i];
+ sort_points[j].angle = atan2 (dy, dx);
+ }
+ }
+
+ qsort (sort_points, num_new - 1, sizeof (SortPoint), ipolygon_sort_func);
+
+ /* now ensure that all turns as we trace the perimeter are
+ counter-clockwise */
+
+ new_points[0] = lowest_pt;
+ new_points[1] = sort_points[0].point;
+ x1 = new_points[1].x - new_points[0].x;
+ y1 = new_points[1].y - new_points[0].y;
+
+ for (i = 1, j = 2; j < num_new; i++, j++)
+ {
+ x2 = sort_points[i].point.x - new_points[j - 1].x;
+ y2 = sort_points[i].point.y - new_points[j - 1].y;
+
+ if (x2 == 0 && y2 == 0)
+ {
+ num_new--;
+ j--;
+ continue;
+ }
+
+ while (x1 * y2 - x2 * y1 < 0) /* clockwise rotation */
+ {
+ num_new--;
+ j--;
+ x1 = new_points[j - 1].x - new_points[j - 2].x;
+ y1 = new_points[j - 1].y - new_points[j - 2].y;
+ x2 = sort_points[i].point.x - new_points[j - 1].x;
+ y2 = sort_points[i].point.y - new_points[j - 1].y;
+ }
+ new_points[j] = sort_points[i].point;
+ x1 = x2;
+ y1 = y2;
+ }
+
+ g_free (sort_points);
+
+ new_poly->npoints = num_new;
+
+ return new_poly;
+}
+
+/* Determines whether a specified point is in the given polygon.
+ Based on
+
+ inpoly.c by Bob Stein and Craig Yap.
+
+ (Linux Journal, Issue 35 (March 1997), p 68)
+ */
+
+gint
+ipolygon_contains (IPolygon *poly,
+ gint xt,
+ gint yt)
+{
+ gint xnew, ynew;
+ gint xold, yold;
+ gint x1,y1;
+ gint x2,y2;
+
+ gint i;
+ gint inside = 0;
+
+ if (poly->npoints < 3)
+ return 0;
+
+ xold=poly->points[poly->npoints - 1].x;
+ yold=poly->points[poly->npoints - 1].y;
+ for (i = 0; i < poly->npoints; i++)
+ {
+ xnew = poly->points[i].x;
+ ynew = poly->points[i].y;
+ if (xnew > xold)
+ {
+ x1 = xold;
+ x2 = xnew;
+ y1 = yold;
+ y2 = ynew;
+ }
+ else
+ {
+ x1 = xnew;
+ x2 = xold;
+ y1 = ynew;
+ y2 = yold;
+ }
+ if ((xnew < xt) == (xt <= xold) &&
+ (yt - y1)*(x2 - x1) < (y2 - y1)*(xt - x1))
+ inside = !inside;
+ xold = xnew;
+ yold = ynew;
+ }
+ return inside;
+}
+
+void
+aff_element_compute_color_trans (AffElement *elem)
+{
+ int i, j;
+
+ if (elem->v.simple_color)
+ {
+ gdouble mag2;
+
+ mag2 = SQR (elem->v.target_color.r);
+ mag2 += SQR (elem->v.target_color.g);
+ mag2 += SQR (elem->v.target_color.b);
+
+ /* For mag2 == 0, the transformation blows up in general
+ but is well defined for hue_scale == value_scale, so
+ we assume that special case. */
+ if (mag2 == 0)
+ for (i = 0; i < 3; i++)
+ {
+ for (j = 0; j < 4; j++)
+ elem->color_trans.vals[i][j] = 0.0;
+
+ elem->color_trans.vals[i][i] = elem->v.hue_scale;
+ }
+ else
+ {
+ /* red */
+ for (j = 0; j < 3; j++)
+ {
+ elem->color_trans.vals[0][j] = elem->v.target_color.r
+ / mag2 * (elem->v.value_scale - elem->v.hue_scale);
+ }
+
+ /* green */
+ for (j = 0; j < 3; j++)
+ {
+ elem->color_trans.vals[1][j] = elem->v.target_color.g
+ / mag2 * (elem->v.value_scale - elem->v.hue_scale);
+ }
+
+ /* blue */
+ for (j = 0; j < 3; j++)
+ {
+ elem->color_trans.vals[2][j] = elem->v.target_color.g
+ / mag2 * (elem->v.value_scale - elem->v.hue_scale);
+ }
+
+ elem->color_trans.vals[0][0] += elem->v.hue_scale;
+ elem->color_trans.vals[1][1] += elem->v.hue_scale;
+ elem->color_trans.vals[2][2] += elem->v.hue_scale;
+
+ elem->color_trans.vals[0][3] =
+ (1 - elem->v.value_scale) * elem->v.target_color.r;
+ elem->color_trans.vals[1][3] =
+ (1 - elem->v.value_scale) * elem->v.target_color.g;
+ elem->color_trans.vals[2][3] =
+ (1 - elem->v.value_scale) * elem->v.target_color.b;
+
+ }
+
+
+ aff3_apply (&elem->color_trans, 1.0, 0.0, 0.0,
+ &elem->v.red_color.r,
+ &elem->v.red_color.g,
+ &elem->v.red_color.b);
+ aff3_apply (&elem->color_trans, 0.0, 1.0, 0.0,
+ &elem->v.green_color.r,
+ &elem->v.green_color.g,
+ &elem->v.green_color.b);
+ aff3_apply (&elem->color_trans, 0.0, 0.0, 1.0,
+ &elem->v.blue_color.r,
+ &elem->v.blue_color.g,
+ &elem->v.blue_color.b);
+ aff3_apply (&elem->color_trans, 0.0, 0.0, 0.0,
+ &elem->v.black_color.r,
+ &elem->v.black_color.g,
+ &elem->v.black_color.b);
+ }
+ else
+ {
+ elem->color_trans.vals[0][0] =
+ elem->v.red_color.r - elem->v.black_color.r;
+ elem->color_trans.vals[1][0] =
+ elem->v.red_color.g - elem->v.black_color.g;
+ elem->color_trans.vals[2][0] =
+ elem->v.red_color.b - elem->v.black_color.b;
+
+ elem->color_trans.vals[0][1] =
+ elem->v.green_color.r - elem->v.black_color.r;
+ elem->color_trans.vals[1][1] =
+ elem->v.green_color.g - elem->v.black_color.g;
+ elem->color_trans.vals[2][1] =
+ elem->v.green_color.b - elem->v.black_color.b;
+
+ elem->color_trans.vals[0][2] =
+ elem->v.blue_color.r - elem->v.black_color.r;
+ elem->color_trans.vals[1][2] =
+ elem->v.blue_color.g - elem->v.black_color.g;
+ elem->color_trans.vals[2][2] =
+ elem->v.blue_color.b - elem->v.black_color.b;
+
+ elem->color_trans.vals[0][3] = elem->v.black_color.r;
+ elem->color_trans.vals[1][3] = elem->v.black_color.g;
+ elem->color_trans.vals[2][3] = elem->v.black_color.b;
+ }
+}
+
+void
+aff_element_compute_trans (AffElement *elem,
+ gdouble width,
+ gdouble height,
+ gdouble center_x,
+ gdouble center_y)
+{
+ Aff2 t1, t2, t3;
+
+ /* create the rotation, scaling and shearing part of the transform */
+ aff2_distort (&t1, elem->v.asym, elem->v.shear);
+ aff2_scale (&t2, elem->v.scale, elem->v.flip);
+ aff2_compose (&t3, &t2, &t1);
+ aff2_rotate (&t2, elem->v.theta);
+ aff2_compose (&t1, &t2, &t3);
+
+ /* now create the translational part */
+ aff2_translate (&t2, -center_x*width, -center_y*width);
+ aff2_compose (&t3, &t1, &t2);
+ aff2_translate (&t2, elem->v.x*width, elem->v.y*width);
+ aff2_compose (&elem->trans, &t2, &t3);
+}
+
+void
+aff_element_decompose_trans (AffElement *elem,
+ Aff2 *aff,
+ gdouble width,
+ gdouble height,
+ gdouble center_x,
+ gdouble center_y)
+{
+ Aff2 t1, t2;
+ gdouble det, scale, sign;
+
+ /* pull of the translational parts */
+ aff2_translate (&t1,center_x * width, center_y * width);
+ aff2_compose (&t2, aff, &t1);
+
+ elem->v.x = t2.b1 / width;
+ elem->v.y = t2.b2 / width;
+
+ det = t2.a11 * t2.a22 - t2.a12 * t2.a21;
+
+ if (det == 0.0)
+ {
+ elem->v.scale = 0.0;
+ elem->v.theta = 0.0;
+ elem->v.asym = 1.0;
+ elem->v.shear = 0.0;
+ elem->v.flip = 0;
+ }
+ else
+ {
+ if (det >= 0)
+ {
+ scale = elem->v.scale = sqrt (det);
+ sign = 1;
+ elem->v.flip = 0;
+ }
+ else
+ {
+ scale = elem->v.scale = sqrt (-det);
+ sign = -1;
+ elem->v.flip = 1;
+ }
+
+ elem->v.theta = atan2 (-t2.a21, t2.a11);
+
+ if (cos (elem->v.theta) == 0.0)
+ {
+ elem->v.asym = - t2.a21 / scale / sin (elem->v.theta);
+ elem->v.shear = - sign * t2.a22 / scale / sin (elem->v.theta);
+ }
+ else
+ {
+ elem->v.asym = sign * t2.a11 / scale / cos (elem->v.theta);
+ elem->v.shear = sign *
+ (t2.a12/scale - sin (elem->v.theta)/elem->v.asym)
+ / cos (elem->v.theta);
+ }
+ }
+}
+
+static void
+aff_element_compute_click_boundary (AffElement *elem,
+ int num_elements,
+ gdouble *points_x,
+ gdouble *points_y)
+{
+ gint i;
+ gdouble xtot = 0;
+ gdouble ytot = 0;
+ gdouble xc, yc;
+ gdouble theta;
+ gdouble sth, cth; /* sin(theta), cos(theta) */
+ gdouble axis1, axis2;
+ gdouble axis1max, axis2max, axis1min, axis2min;
+
+ /* compute the center of mass of the points */
+ for (i = 0; i < num_elements; i++)
+ {
+ xtot += points_x[i];
+ ytot += points_y[i];
+ }
+ xc = xtot / num_elements;
+ yc = ytot / num_elements;
+
+ /* compute the sum of the (x+iy)^2, and take half the the resulting
+ angle (xtot+iytot = A*exp(2i*theta)), to get an average direction */
+
+ xtot = 0;
+ ytot = 0;
+ for (i = 0; i < num_elements; i++)
+ {
+ xtot += SQR (points_x[i] - xc) - SQR (points_y[i] - yc);
+ ytot += 2 * (points_x[i] - xc) * (points_y[i] - yc);
+ }
+ theta = 0.5 * atan2 (ytot, xtot);
+ sth = sin (theta);
+ cth = cos (theta);
+
+ /* compute the minimum rectangle at angle theta that bounds the points,
+ 1/2 side lengths left in axis1, axis2, center in xc, yc */
+
+ axis1max = axis1min = 0.0;
+ axis2max = axis2min = 0.0;
+ for (i = 0; i < num_elements; i++)
+ {
+ gdouble proj1 = (points_x[i] - xc) * cth + (points_y[i] - yc) * sth;
+ gdouble proj2 = -(points_x[i] - xc) * sth + (points_y[i] - yc) * cth;
+ if (proj1 < axis1min)
+ axis1min = proj1;
+ if (proj1 > axis1max)
+ axis1max = proj1;
+ if (proj2 < axis2min)
+ axis2min = proj2;
+ if (proj2 > axis2max)
+ axis2max = proj2;
+ }
+ axis1 = 0.5 * (axis1max - axis1min);
+ axis2 = 0.5 * (axis2max - axis2min);
+ xc += 0.5 * ((axis1max + axis1min) * cth - (axis2max + axis2min) * sth);
+ yc += 0.5 * ((axis1max + axis1min) * sth + (axis2max + axis2min) * cth);
+
+ /* if the the rectangle is less than 10 pixels in any dimension,
+ make it click_boundary, otherwise set click_boundary = draw_boundary */
+
+ if (axis1 < 8.0 || axis2 < 8.0)
+ {
+ GdkPoint *points = g_new (GdkPoint, 4);
+
+ elem->click_boundary = g_new (IPolygon, 1);
+ elem->click_boundary->points = points;
+ elem->click_boundary->npoints = 4;
+
+ if (axis1 < 8.0) axis1 = 8.0;
+ if (axis2 < 8.0) axis2 = 8.0;
+
+ points[0].x = xc + axis1 * cth - axis2 * sth;
+ points[0].y = yc + axis1 * sth + axis2 * cth;
+ points[1].x = xc - axis1 * cth - axis2 * sth;
+ points[1].y = yc - axis1 * sth + axis2 * cth;
+ points[2].x = xc - axis1 * cth + axis2 * sth;
+ points[2].y = yc - axis1 * sth - axis2 * cth;
+ points[3].x = xc + axis1 * cth + axis2 * sth;
+ points[3].y = yc + axis1 * sth - axis2 * cth;
+ }
+ else
+ elem->click_boundary = elem->draw_boundary;
+}
+
+void
+aff_element_compute_boundary (AffElement *elem,
+ gint width,
+ gint height,
+ AffElement **elements,
+ gint num_elements)
+{
+ gint i;
+ IPolygon tmp_poly;
+ gdouble *points_x;
+ gdouble *points_y;
+
+ if (elem->click_boundary && elem->click_boundary != elem->draw_boundary)
+ g_free (elem->click_boundary);
+ if (elem->draw_boundary)
+ g_free (elem->draw_boundary);
+
+ tmp_poly.npoints = num_elements;
+ tmp_poly.points = g_new (GdkPoint, num_elements);
+ points_x = g_new (gdouble, num_elements);
+ points_y = g_new (gdouble, num_elements);
+
+ for (i = 0; i < num_elements; i++)
+ {
+ aff2_apply (&elem->trans,
+ elements[i]->v.x * width, elements[i]->v.y * width,
+ &points_x[i],&points_y[i]);
+ tmp_poly.points[i].x = (gint)points_x[i];
+ tmp_poly.points[i].y = (gint)points_y[i];
+ }
+
+ elem->draw_boundary = ipolygon_convex_hull (&tmp_poly);
+ aff_element_compute_click_boundary (elem, num_elements, points_x, points_y);
+
+ g_free (tmp_poly.points);
+}
+
+void
+aff_element_draw (AffElement *elem,
+ gboolean selected,
+ gint width,
+ gint height,
+ cairo_t *cr,
+ GdkColor *color,
+ PangoLayout *layout)
+{
+ PangoRectangle rect;
+ gint i;
+
+ pango_layout_set_text (layout, elem->name, -1);
+ pango_layout_get_pixel_extents (layout, NULL, &rect);
+
+ gdk_cairo_set_source_color (cr, color);
+
+ cairo_move_to (cr,
+ elem->v.x * width - rect.width / 2,
+ elem->v.y * width + rect.height / 2);
+ pango_cairo_show_layout (cr, layout);
+ cairo_fill (cr);
+
+ cairo_set_line_width (cr, 1.0);
+
+ if (elem->click_boundary != elem->draw_boundary)
+ {
+ cairo_move_to (cr,
+ elem->click_boundary->points[0].x,
+ elem->click_boundary->points[0].y);
+
+ for (i = 1; i < elem->click_boundary->npoints; i++)
+ cairo_line_to (cr,
+ elem->click_boundary->points[i].x,
+ elem->click_boundary->points[i].y);
+
+ cairo_close_path (cr);
+
+ cairo_stroke (cr);
+ }
+
+ if (selected)
+ cairo_set_line_width (cr, 3.0);
+
+ cairo_move_to (cr,
+ elem->draw_boundary->points[0].x,
+ elem->draw_boundary->points[0].y);
+
+ for (i = 1; i < elem->draw_boundary->npoints; i++)
+ cairo_line_to (cr,
+ elem->draw_boundary->points[i].x,
+ elem->draw_boundary->points[i].y);
+
+ cairo_close_path (cr);
+
+ cairo_stroke (cr);
+}
+
+AffElement *
+aff_element_new (gdouble x,
+ gdouble y,
+ GimpRGB *color,
+ gint count)
+{
+ AffElement *elem = g_new (AffElement, 1);
+ gchar buffer[16];
+
+ elem->v.x = x;
+ elem->v.y = y;
+ elem->v.theta = 0.0;
+ elem->v.scale = 0.5;
+ elem->v.asym = 1.0;
+ elem->v.shear = 0.0;
+ elem->v.flip = 0;
+
+ elem->v.red_color = *color;
+ elem->v.blue_color = *color;
+ elem->v.green_color = *color;
+ elem->v.black_color = *color;
+
+ elem->v.target_color = *color;
+ elem->v.hue_scale = 0.5;
+ elem->v.value_scale = 0.5;
+
+ elem->v.simple_color = TRUE;
+
+ elem->draw_boundary = NULL;
+ elem->click_boundary = NULL;
+
+ aff_element_compute_color_trans (elem);
+
+ elem->v.prob = 1.0;
+
+ sprintf (buffer,"%d", count);
+ elem->name = g_strdup (buffer);
+
+ return elem;
+}
+
+void
+aff_element_free (AffElement *elem)
+{
+ if (elem->click_boundary != elem->draw_boundary)
+ g_free (elem->click_boundary);
+
+ g_free (elem->draw_boundary);
+ g_free (elem);
+}
+
+#ifdef DEBUG_BRUSH
+static brush_chars[] = {' ',':','*','@'};
+#endif
+
+static guchar *
+create_brush (IfsComposeVals *ifsvals,
+ gint *brush_size,
+ gdouble *brush_offset)
+{
+ gint i, j;
+ gint ii, jj;
+ guchar *brush;
+#ifdef DEBUG_BRUSH
+ gdouble totpix = 0.0;
+#endif
+
+ gdouble radius = ifsvals->radius * ifsvals->subdivide;
+
+ *brush_size = ceil (2 * radius);
+ *brush_offset = 0.5 * (*brush_size - 1);
+
+ brush = g_new (guchar, SQR (*brush_size));
+
+ for (i = 0; i < *brush_size; i++)
+ {
+ for (j = 0; j < *brush_size; j++)
+ {
+ gdouble pixel = 0.0;
+ gdouble d = sqrt (SQR (i - *brush_offset) +
+ SQR (j - *brush_offset));
+
+ if (d - 0.5 * G_SQRT2 > radius)
+ pixel = 0.0;
+ else if (d + 0.5 * G_SQRT2 < radius)
+ pixel = 1.0;
+ else
+ for (ii = 0; ii < 10; ii++)
+ for (jj = 0; jj < 10; jj++)
+ {
+ d = sqrt (SQR (i - *brush_offset + ii * 0.1 - 0.45) +
+ SQR (j - *brush_offset + jj * 0.1 - 0.45));
+ pixel += (d < radius) / 100.0;
+ }
+
+ brush[i * *brush_size + j] = 255.999 * pixel;
+
+#ifdef DEBUG_BRUSH
+ putchar(brush_chars[(gint)(pixel * 3.999)]);
+ totpix += pixel;
+#endif /* DEBUG_BRUSH */
+ }
+#ifdef DEBUG_BRUSH
+ putchar('\n');
+#endif /* DEBUG_BRUSH */
+ }
+#ifdef DEBUG_BRUSH
+ printf ("Brush total / area = %f\n", totpix / SQR (ifsvals->subdivide));
+#endif /* DEBUG_BRUSH */
+ return brush;
+}
+
+void
+ifs_render (AffElement **elements,
+ gint num_elements,
+ gint width,
+ gint height,
+ gint nsteps,
+ IfsComposeVals *vals,
+ gint band_y,
+ gint band_height,
+ guchar *data,
+ guchar *mask,
+ guchar *nhits,
+ gboolean preview)
+{
+ gint i, k, n;
+ gdouble x, y;
+ gdouble r, g, b;
+ gint ri, gi, bi;
+ guint32 p0, psum;
+ gdouble pt;
+ guchar *ptr;
+ guint32 *prob;
+ gdouble *fprob;
+ gint subdivide;
+ guchar *brush = NULL;
+ gint brush_size = 1;
+ gdouble brush_offset = 0.0;
+
+ if (preview)
+ subdivide = 1;
+ else
+ subdivide = vals->subdivide;
+
+ /* compute the probabilities and transforms */
+ fprob = g_new (gdouble, num_elements);
+ prob = g_new (guint32, num_elements);
+ pt = 0.0;
+
+ for (i = 0; i < num_elements; i++)
+ {
+ aff_element_compute_trans(elements[i],
+ width * subdivide,
+ height * subdivide,
+ vals->center_x,
+ vals->center_y);
+ fprob[i] = fabs(
+ elements[i]->trans.a11 * elements[i]->trans.a22
+ - elements[i]->trans.a12 * elements[i]->trans.a21);
+
+ /* As a heuristic, if the determinant is really small, it's
+ probably a line element, so increase the probability so
+ it gets rendered */
+
+ /* FIXME: figure out what 0.01 really should be */
+ if (fprob[i] < 0.01)
+ fprob[i] = 0.01;
+
+ fprob[i] *= elements[i]->v.prob;
+
+ pt += fprob[i];
+ }
+
+ psum = 0;
+ for (i = 0; i < num_elements; i++)
+ {
+ psum += (guint32) -1 * (fprob[i] / pt);
+ prob[i] = psum;
+ }
+
+ prob[i - 1] = (guint32) -1; /* make sure we don't get bitten by roundoff */
+
+ /* create the brush */
+ if (!preview)
+ brush = create_brush (vals, &brush_size, &brush_offset);
+
+ x = y = 0;
+ r = g = b = 0;
+
+ /* n is used to limit the number of progress updates */
+ n = nsteps / 32;
+
+ /* now run the iteration */
+ for (i = 0; i < nsteps; i++)
+ {
+ if (!preview && ((i % n) == 0))
+ gimp_progress_update ((gdouble) i / (gdouble) nsteps);
+
+ p0 = g_random_int ();
+ k = 0;
+
+ while (p0 > prob[k])
+ k++;
+
+ aff2_apply (&elements[k]->trans, x, y, &x, &y);
+ aff3_apply (&elements[k]->color_trans, r, g, b, &r, &g, &b);
+
+ if (i < 50)
+ continue;
+
+ ri = (gint) (255.0 * r + 0.5);
+ gi = (gint) (255.0 * g + 0.5);
+ bi = (gint) (255.0 * b + 0.5);
+
+ if ((ri < 0) || (ri > 255) ||
+ (gi < 0) || (gi > 255) ||
+ (bi < 0) || (bi > 255))
+ continue;
+
+ if (preview)
+ {
+ if ((x < width) && (y < (band_y + band_height)) &&
+ (x >= 0) && (y >= band_y))
+ {
+ ptr = data + 3 * (((gint) (y - band_y)) * width + (gint) x);
+
+ *ptr++ = ri;
+ *ptr++ = gi;
+ *ptr = bi;
+ }
+ }
+ else
+ {
+ if ((x < width * subdivide) && (y < height * subdivide) &&
+ (x >= 0) && (y >= 0))
+ {
+ gint ii;
+ gint jj;
+ gint jj0 = floor (y - brush_offset - band_y * subdivide);
+ gint ii0 = floor (x - brush_offset);
+ gint jjmin = 0;
+ gint iimin = 0;
+ gint jjmax;
+ gint iimax;
+
+ if (ii0 < 0)
+ iimin = - ii0;
+ else
+ iimin = 0;
+
+ if (jj0 < 0)
+ jjmin = - jj0;
+ else
+ jjmin = 0;
+
+ if (jj0 + brush_size >= subdivide * band_height)
+ jjmax = subdivide * band_height - jj0;
+ else
+ jjmax = brush_size;
+
+ if (ii0 + brush_size >= subdivide * width)
+ iimax = subdivide * width - ii0;
+ else
+ iimax = brush_size;
+
+ for (jj = jjmin; jj < jjmax; jj++)
+ for (ii = iimin; ii < iimax; ii++)
+ {
+ guint m_old;
+ guint m_new;
+ guint m_pix;
+ guint n_hits;
+ guint old_scale;
+ guint pix_scale;
+ gint index = (jj0 + jj) * width * subdivide + ii0 + ii;
+
+ n_hits = nhits[index];
+ if (n_hits == 255)
+ continue;
+
+ m_pix = brush[jj * brush_size + ii];
+ if (!m_pix)
+ continue;
+
+ nhits[index] = ++n_hits;
+ m_old = mask[index];
+ m_new = m_old + m_pix - m_old * m_pix / 255;
+ mask[index] = m_new;
+
+ /* relative probability that old colored pixel is on top */
+ old_scale = m_old * (255 * n_hits - m_pix);
+
+ /* relative probability that new colored pixel is on top */
+ pix_scale = m_pix * ((255 - m_old) * n_hits + m_old);
+
+ ptr = data + 3 * index;
+
+ *ptr = ((old_scale * (*ptr) + pix_scale * ri) /
+ (old_scale + pix_scale));
+ ptr++;
+
+ *ptr = ((old_scale * (*ptr) + pix_scale * gi) /
+ (old_scale + pix_scale));
+ ptr++;
+
+ *ptr = ((old_scale * (*ptr) + pix_scale * bi) /
+ (old_scale + pix_scale));
+ }
+ }
+ }
+ } /* main iteration */
+
+ if (!preview )
+ gimp_progress_update (1.0);
+
+ g_free (brush);
+ g_free (prob);
+ g_free (fprob);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-30 11:11:43 +0000