--- /dev/null
+/* -*- indent-tabs-mode: nil; tab-width: 4; c-basic-offset: 4; -*-
+
+ overlap.c for the Openbox window manager
+ Copyright (c) 2011 Ian Zimmerman
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 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.
+
+ See the COPYING file for a copy of the GNU General Public License.
+*/
+
+#include "config.h"
+#include "geom.h"
+#include "place_overlap.h"
+
+#include <stdlib.h>
+
+static void make_grid(const Rect* client_rects, int n_client_rects,
+ const Rect* bound, int* x_edges, int* y_edges,
+ int max_edges);
+
+static int best_direction(const Point* grid_point,
+ const Rect* client_rects, int n_client_rects,
+ const Rect* bound, const Size* req_size,
+ Point* best_top_left);
+
+/* Choose the placement on a grid with least overlap */
+
+void place_overlap_find_least_placement(const Rect* client_rects,
+ int n_client_rects,
+ Rect *const bound,
+ const Size* req_size,
+ Point* result)
+{
+ result->x = result->y = 0;
+ int overlap = G_MAXINT;
+ int max_edges = 2 * (n_client_rects + 1);
+
+ int x_edges[max_edges];
+ int y_edges[max_edges];
+ make_grid(client_rects, n_client_rects, bound,
+ x_edges, y_edges, max_edges);
+ int i;
+ for (i = 0; i < max_edges; ++i) {
+ if (x_edges[i] == G_MAXINT)
+ break;
+ int j;
+ for (j = 0; j < max_edges; ++j) {
+ if (y_edges[j] == G_MAXINT)
+ break;
+ Point grid_point = {.x = x_edges[i], .y = y_edges[j]};
+ Point best_top_left;
+ int this_overlap =
+ best_direction(&grid_point, client_rects, n_client_rects,
+ bound, req_size, &best_top_left);
+ if (this_overlap < overlap) {
+ overlap = this_overlap;
+ *result = best_top_left;
+ }
+ if (overlap == 0)
+ break;
+ }
+ if (overlap == 0)
+ break;
+ }
+}
+
+static int compare_ints(const void* a, const void* b)
+{
+ const int* ia = (const int*)a;
+ const int* ib = (const int*)b;
+ return *ia - *ib;
+}
+
+static void uniquify(int* edges, int n_edges)
+{
+ int i = 0;
+ int j = 0;
+
+ while (j < n_edges) {
+ int last = edges[j++];
+ edges[i++] = last;
+ while (j < n_edges && edges[j] == last)
+ ++j;
+ }
+ /* fill the rest with nonsense */
+ for (; i < n_edges ; ++i)
+ edges[i] = G_MAXINT;
+}
+
+static void make_grid(const Rect* client_rects, int n_client_rects,
+ const Rect* bound, int* x_edges, int* y_edges,
+ int max_edges)
+{
+ int i;
+ int n_edges = 0;
+ for (i = 0; i < n_client_rects; ++i) {
+ if (!RECT_INTERSECTS_RECT(client_rects[i], *bound))
+ continue;
+ x_edges[n_edges] = client_rects[i].x;
+ y_edges[n_edges++] = client_rects[i].y;
+ x_edges[n_edges] = client_rects[i].x + client_rects[i].width;
+ y_edges[n_edges++] = client_rects[i].y + client_rects[i].height;
+ }
+ x_edges[n_edges] = bound->x;
+ y_edges[n_edges++] = bound->y;
+ x_edges[n_edges] = bound->x + bound->width;
+ y_edges[n_edges++] = bound->y + bound->height;
+ for (i = n_edges; i < max_edges; ++i)
+ x_edges[i] = y_edges[i] = G_MAXINT;
+ qsort(x_edges, n_edges, sizeof(int), compare_ints);
+ uniquify(x_edges, n_edges);
+ qsort(y_edges, n_edges, sizeof(int), compare_ints);
+ uniquify(y_edges, n_edges);
+}
+
+static int total_overlap(const Rect* client_rects, int n_client_rects,
+ const Rect* proposed_rect)
+{
+ int overlap = 0;
+ int i;
+ for (i = 0; i < n_client_rects; ++i) {
+ if (!RECT_INTERSECTS_RECT(*proposed_rect, client_rects[i]))
+ continue;
+ Rect rtemp;
+ RECT_SET_INTERSECTION(rtemp, *proposed_rect, client_rects[i]);
+ overlap += RECT_AREA(rtemp);
+ }
+ return overlap;
+}
+
+/* Given a list of Rect RECTS, a Point PT and a Size size, determine the
+ direction from PT which results in the least total overlap with RECTS
+ if a rectangle is placed in that direction. Return the top/left
+ Point of such rectangle and the resulting overlap amount. Only
+ consider placements within BOUNDS. */
+
+#define NUM_DIRECTIONS 4
+
+static int best_direction(const Point* grid_point,
+ const Rect* client_rects, int n_client_rects,
+ const Rect* bound, const Size* req_size,
+ Point* best_top_left)
+{
+ static const Size directions[NUM_DIRECTIONS] = {
+ {0, 0}, {0, -1}, {-1, 0}, {-1, -1}
+ };
+ int overlap = G_MAXINT;
+ int i;
+ for (i = 0; i < NUM_DIRECTIONS; ++i) {
+ Point pt = {
+ .x = grid_point->x + (req_size->width * directions[i].width),
+ .y = grid_point->y + (req_size->height * directions[i].height)
+ };
+ Rect r;
+ RECT_SET(r, pt.x, pt.y, req_size->width, req_size->height);
+ if (!RECT_CONTAINS_RECT(*bound, r))
+ continue;
+ int this_overlap = total_overlap(client_rects, n_client_rects, &r);
+ if (this_overlap < overlap) {
+ overlap = this_overlap;
+ *best_top_left = pt;
+ }
+ if (overlap == 0)
+ break;
+ }
+ return overlap;
+}