video: Add a function to draw a rectangle

Provide a way to draw an unfilled box of a certain width. This is useful
for grouping menu items together.

Add a comment showing how to see the copy-framebuffer, for testing.

Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/video/video-uclass.c

@@ -26,6 +26,7 @@
 #ifdef CONFIG_SANDBOX
 #include <asm/sdl.h>
 #endif
+#include "vidconsole_internal.h"
 
 /*
  * Theory of operation:
@@ -216,6 +217,40 @@ int video_fill_part(struct udevice *dev, int xstart, int ystart, int xend,
 	return 0;
 }
 
+int video_draw_box(struct udevice *dev, int x0, int y0, int x1, int y1,
+		   int width, u32 colour)
+{
+	struct video_priv *priv = dev_get_uclass_priv(dev);
+	int pbytes = VNBYTES(priv->bpix);
+	void *start, *line;
+	int pixels = x1 - x0;
+	int row;
+
+	start = priv->fb + y0 * priv->line_length;
+	start += x0 * pbytes;
+	line = start;
+	for (row = y0; row < y1; row++) {
+		void *ptr = line;
+		int i;
+
+		for (i = 0; i < width; i++)
+			fill_pixel_and_goto_next(&ptr, colour, pbytes, pbytes);
+		if (row < y0 + width || row >= y1 - width) {
+			for (i = 0; i < pixels - width * 2; i++)
+				fill_pixel_and_goto_next(&ptr, colour, pbytes,
+							 pbytes);
+		} else {
+			ptr += (pixels - width * 2) * pbytes;
+		}
+		for (i = 0; i < width; i++)
+			fill_pixel_and_goto_next(&ptr, colour, pbytes, pbytes);
+		line += priv->line_length;
+	}
+	video_damage(dev, x0, y0, x1 - x0, y1 - y0);
+
+	return 0;
+}
+
 int video_reserve_from_bloblist(struct video_handoff *ho)
 {
 	if (!ho->fb || ho->size == 0)
@@ -481,6 +516,7 @@ int video_sync(struct udevice *vid, bool force)
 		video_flush_dcache(vid, true);
 
 #if defined(CONFIG_VIDEO_SANDBOX_SDL)
+	/* to see the copy framebuffer, use priv->copy_fb */
 	sandbox_sdl_sync(priv->fb);
 #endif
 	priv->last_sync = get_timer(0);

include/video.h

@@ -249,7 +249,7 @@ int video_fill(struct udevice *dev, u32 colour);
 /**
  * video_fill_part() - Erase a region
  *
- * Erase a rectangle of the display within the given bounds.
+ * Erase a rectangle on the display within the given bounds
  *
  * @dev:	Device to update
  * @xstart:	X start position in pixels from the left
@@ -262,6 +262,23 @@ int video_fill(struct udevice *dev, u32 colour);
 int video_fill_part(struct udevice *dev, int xstart, int ystart, int xend,
 		    int yend, u32 colour);
 
+/**
+ * video_draw_box() - Draw a box
+ *
+ * Draw a rectangle on the display within the given bounds
+ *
+ * @dev:	Device to update
+ * @x0:		X start position in pixels from the left
+ * @y0:		Y start position in pixels from the top
+ * @x1:		X end position in pixels from the left
+ * @y1:		Y end position in pixels from the top
+ * @width:	width in pixels
+ * @colour:	Value to write
+ * Return: 0 if OK, -ENOSYS if the display depth is not supported
+ */
+int video_draw_box(struct udevice *dev, int x0, int y0, int x1, int y1,
+		   int width, u32 colour);
+
 /**
  * video_sync() - Sync a device's frame buffer with its hardware
  *

test/dm/video.c

@@ -902,3 +902,24 @@ static int dm_test_video_silence(struct unit_test_state *uts)
 	return 0;
 }
 DM_TEST(dm_test_video_silence, UTF_SCAN_FDT);
+
+/* test drawing a box */
+static int dm_test_video_box(struct unit_test_state *uts)
+{
+	struct video_priv *priv;
+	struct udevice *dev;
+
+	ut_assertok(video_get_nologo(uts, &dev));
+	priv = dev_get_uclass_priv(dev);
+	video_draw_box(dev, 100, 100, 200, 200, 3,
+		       video_index_to_colour(priv, VID_LIGHT_BLUE));
+	video_draw_box(dev, 300, 100, 400, 200, 1,
+		       video_index_to_colour(priv, VID_MAGENTA));
+	video_draw_box(dev, 500, 100, 600, 200, 20,
+		       video_index_to_colour(priv, VID_LIGHT_RED));
+	ut_asserteq(133, video_compress_fb(uts, dev, false));
+	ut_assertok(video_check_copy_fb(uts, dev));
+
+	return 0;
+}
+DM_TEST(dm_test_video_box, UTF_SCAN_FDT);