Implement damage buffer conversion

include/damage.h

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2020 Andri Yngvason
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <stdio.h>
+
+struct pixman_region16;
+struct pixman_box16;
+
+void damage_check(struct pixman_region16* damage, const uint8_t* buffer,
+                  uint32_t width, uint32_t height, struct pixman_box16* hint);
+
+void damage_dump(FILE* stream, struct pixman_region16* damage,
+                 uint32_t width, uint32_t height, uint32_t tile_size);

src/damage.c

@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2020 Andri Yngvason
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <assert.h>
+#include <sys/param.h>
+#include <pixman.h>
+
+#define UDIV_UP(a, b) (((a) + (b) - 1) / (b))
+
+bool damage_check_32_byte_block(const void* block)
+{
+	const uint64_t* a = block;
+	return a[0] || a[1] || a[2] || a[3];
+}
+
+void damage_check_row(uint8_t* dst, const uint8_t* src, uint32_t width)
+{
+	uint32_t aligned_width = (width / 32) * 32;
+
+	for (uint32_t x = 0; x < aligned_width; x += 32)
+		dst[x / 32] |= damage_check_32_byte_block(&src[x]);
+
+	for (uint32_t x = aligned_width; x < width; ++x)
+		dst[x / 32] |= src[x];
+}
+
+void damage_check_tile_row(struct pixman_region16* damage,
+                           uint8_t* row_buffer, const uint8_t* buffer,
+			   uint32_t y_start, uint32_t width, uint32_t height)
+{
+	memset(row_buffer, 0, width / 32);
+
+	for (uint32_t y = y_start; y < y_start + height; ++y)
+		damage_check_row(row_buffer, buffer + y * width, width);
+
+	for (uint32_t x = 0; x < width / 32; ++x)
+		if (row_buffer[x])
+			pixman_region_union_rect(damage, damage,
+			                         x * 32, y_start, 32, 32);
+}
+
+void damage_check(struct pixman_region16* damage, const uint8_t* buffer,
+                  uint32_t width, uint32_t height, struct pixman_box16* hint)
+{
+	uint32_t tiled_width = UDIV_UP(width, 32);
+	uint8_t* row_buffer = malloc(tiled_width);
+	assert(row_buffer);
+
+	for (uint32_t y = 0; y < height; y += 32) {
+		uint32_t current_height = MIN(32, height - y);
+		damage_check_tile_row(damage, row_buffer, buffer, y, width,
+		                      current_height);
+	}
+
+	free(row_buffer);
+}
+
+void damage_dump(FILE* stream, struct pixman_region16* damage,
+                 uint32_t width, uint32_t height, uint32_t tile_size)
+{
+	uint32_t tiled_width = UDIV_UP(width, tile_size);
+	uint32_t tiled_height = UDIV_UP(height, tile_size);
+
+	fprintf(stream, "\033[2J");
+
+	for (uint32_t y = 0; y < tiled_height; ++y) {
+		for (uint32_t x = 0; x < tiled_width; ++x) {
+			struct pixman_box16 box = {
+				.x1 = x * tile_size,
+				.x2 = ((x + 1) * tile_size) - 1,
+				.y1 = y * tile_size,
+				.y2 = ((y + 1) * tile_size) - 1,
+			};
+
+			pixman_region_overlap_t overlap =
+				pixman_region_contains_rectangle(damage, &box); 
+
+			putc(overlap == PIXMAN_REGION_IN ? 'x' : ' ', stream);
+		}
+		putc('\n', stream);
+	}
+}