--- /dev/null
+/*
+ * Copyright (C) 2020 Collabora, Ltd.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+
+#include "util/ralloc.h"
+#include "pan_partial_update.h"
+
+static struct pan_rect
+pan_make_rect(unsigned minx, unsigned miny, unsigned maxx, unsigned maxy)
+{
+ struct pan_rect r = {
+ .minx = minx,
+ .miny = miny,
+ .maxx = maxx,
+ .maxy = maxy
+ };
+
+ return r;
+}
+
+static struct pan_rect
+pan_from_pipe(const struct pipe_box *p)
+{
+ return pan_make_rect(p->x, p->y, p->x + p->width, p->y + p->height);
+}
+
+/* Helper to clip a rect inside another box */
+
+static struct pan_rect
+pan_clip_rect(
+ const struct pan_rect *r,
+ const struct pan_rect *clip)
+{
+ unsigned minx = MAX2(r->minx, clip->minx);
+ unsigned miny = MAX2(r->miny, clip->miny);
+ unsigned maxx = MAX2(MIN2(r->maxx, clip->maxx), minx);
+ unsigned maxy = MAX2(MIN2(r->maxy, clip->maxy), miny);
+
+ return pan_make_rect(minx, miny, maxx, maxy);
+}
+
+/* Subtract d from r, yielding four (possibly degenerate) rectangles for each
+ * bounding region */
+
+static void
+pan_subtract_from_rect(
+ struct pan_rect *out,
+ const struct pan_rect *r,
+ const struct pan_rect *d)
+{
+ struct pan_rect dc = pan_clip_rect(r, d);
+
+ out[0] = pan_make_rect(r->minx, r->miny, dc.minx, r->maxy);
+ out[1] = pan_make_rect(dc.minx, r->miny, dc.maxx, dc.miny);
+ out[2] = pan_make_rect(dc.maxx, r->miny, r->maxx, r->maxy);
+ out[3] = pan_make_rect(dc.minx, dc.maxy, dc.maxx, r->maxy);
+}
+
+/* Subtract d from the set of rects R, returning the number of
+ * (non-degenerate) rectangles returned.
+ *
+ * out must be at least sizeof(struct pan_rect) * R_len * 4 bytes
+ *
+ * Trivially satisfies: return value < (R_len * 4) */
+
+static unsigned
+pan_subtract_from_rects(
+ struct pan_rect *out,
+ const struct pan_rect *R,
+ unsigned R_len,
+ const struct pan_rect *d)
+{
+ unsigned count = 0;
+ struct pan_rect temp[4];
+
+ for (unsigned r = 0; r < R_len; ++r) {
+ pan_subtract_from_rect(temp, &R[r], d);
+
+ /* Copy the rectangles with nonzero area */
+ for (unsigned i = 0; i < 4; ++i) {
+ if (temp[i].maxx <= temp[i].minx) continue;
+ if (temp[i].maxy <= temp[i].miny) continue;
+
+ out[count++] = temp[i];
+ }
+ }
+
+ return count;
+}
+
+struct pan_rect *
+pan_subtract_damage(
+ void *memctx,
+ unsigned initial_w, unsigned initial_h,
+ unsigned nrects,
+ const struct pipe_box *rects,
+ unsigned *out_len)
+{
+ struct pan_rect *R = ralloc(memctx, struct pan_rect);
+ *R = pan_make_rect(0, 0, initial_w, initial_h);
+ unsigned R_len = 1;
+
+ for (unsigned d = 0; d < nrects; ++d) {
+ const struct pan_rect D = pan_from_pipe(&rects[d]);
+ struct pan_rect *out = rzalloc_array(memctx, struct pan_rect,
+ R_len * 4);
+
+ R_len = pan_subtract_from_rects(out, R, R_len, &D);
+ ralloc_free(R);
+ R = out;
+ }
+
+ *out_len = R_len;
+ return R;
+}
--- /dev/null
+/*
+ * Copyright (C) 2019 Collabora, Ltd.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Authors (Collabora):
+ * Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
+ *
+ */
+
+#ifndef __PAN_PARTIAL_UPDATE_H
+#define __PAN_PARTIAL_UPDATE_H
+
+#include "pipe/p_state.h"
+
+/* Like pipe_box but in terms of maxx/maxy instead of w/h, which is much easier
+ * to work with for our purposes */
+
+struct pan_rect {
+ unsigned minx, miny;
+ unsigned maxx, maxy;
+};
+
+struct pan_rect *
+pan_subtract_damage(
+ void *memctx,
+ unsigned initial_w, unsigned initial_h,
+ unsigned nrects,
+ const struct pipe_box *rects,
+ unsigned *R_len);
+
+#endif