add double buffering

1 files changed, 20 insertions, 6 deletions

diff --git a/drw.c b/drw.c
index dc220dc..79f4ab1 100644
--- a/drw.c
+++ b/drw.c
@@ -53,7 +53,7 @@ create_drw(struct wl_shm *shm, unsigned width, unsigned height)
 		return NULL;
 	}
 
-	canvas->data = mmap(
+	canvas->buffer_data = mmap(
 			NULL,
 			canvas->size,
 			PROT_READ | PROT_WRITE,
@@ -62,10 +62,8 @@ create_drw(struct wl_shm *shm, unsigned width, unsigned height)
 			0
 		);
 
-	if (canvas->data == MAP_FAILED) {
-		close(fd);
-		return NULL;
-	}
+	if (canvas->buffer_data == MAP_FAILED)
+		die("mmap failed: ");
 
 	pool = wl_shm_create_pool(
 			shm,
@@ -85,6 +83,14 @@ create_drw(struct wl_shm *shm, unsigned width, unsigned height)
 	wl_shm_pool_destroy(pool);
 	close(fd);
 
+	fd = allocate_shm_file(canvas->size);
+	canvas->data = mmap(NULL, canvas->size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+
+	if (canvas->data == MAP_FAILED)
+		die("mmap failed: ");
+
+	close(fd);
+
 	return canvas;
 }
 
@@ -93,11 +99,19 @@ void
 free_drw(Canvas *canvas)
 {
 	munmap(canvas->data, canvas->size);
+	munmap(canvas->buffer_data, canvas->size);
 	free(canvas);
 }
 
 
 void
+push_buffer(Canvas *canvas)
+{
+	memcpy(canvas->buffer_data, canvas->data, canvas->size);
+}
+
+
+void
 draw_point(Canvas *canvas, unsigned x, unsigned y, uint32_t color)
 {
 	if (!(x < canvas->width && y < canvas->height))
@@ -159,7 +173,7 @@ font_cache_generate_box(FontCache *fontcache)
 	Font *font = get_font_with_charcode(fontcache, 0);
 	FT_Set_Pixel_Sizes(font->face, 0, fontcache->fontsize);
 	fprintf(stderr, "fontsize: %i\n", fontcache->fontsize);
-	fontcache->box.width = (font->face->bbox.xMax - font->face->bbox.xMin) >> 6;
+	fontcache->box.width = (font->face->size->metrics.max_advance) >> 6;
 	fontcache->box.height = (font->face->size->metrics.height) >> 6;
 	fprintf(stderr, "width: %i, height: %i\n", fontcache->box.width, fontcache->box.height);
 }