console: Allow measuring the bounding box of text

For laying out text accurately it is necessary to know the width and
height of the text. Add a measure() method to the console API, so this
can be supported.

Add an implementation for truetype and a base implementation for the
normal console.

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

1 files changed, 48 insertions, 0 deletions

diff --git a/include/video_console.h b/include/video_console.h
index 81d4c4d874..2694e44f6e 100644
--- a/include/video_console.h
+++ b/include/video_console.h
@@ -83,6 +83,27 @@ struct vidconsole_colour {
 };
 
 /**
+ * struct vidconsole_bbox - Bounding box of text
+ *
+ * This describes the bounding box of something, measured in pixels. The x0/y0
+ * pair is inclusive; the x1/y2 pair is exclusive, meaning that it is one pixel
+ * beyond the extent of the object
+ *
+ * @valid: Values are valid (bounding box is known)
+ * @x0: left x position, in pixels from left side
+ * @y0: top y position, in pixels from top
+ * @x1: right x position + 1
+ * @y1: botton y position + 1
+ */
+struct vidconsole_bbox {
+	bool valid;
+	int x0;
+	int y0;
+	int x1;
+	int y1;
+};
+
+/**
  * struct vidconsole_ops - Video console operations
  *
  * These operations work on either an absolute console position (measured
@@ -189,6 +210,20 @@ struct vidconsole_ops {
 	 * Returns: 0 on success, -ENOENT if no such font
 	 */
 	int (*select_font)(struct udevice *dev, const char *name, uint size);
+
+	/**
+	 * measure() - Measure the bounds of some text
+	 *
+	 * @dev:	Device to adjust
+	 * @name:	Font name to use (NULL to use default)
+	 * @size:	Font size to use (0 to use default)
+	 * @text:	Text to measure
+	 * @bbox:	Returns bounding box of text, assuming it is positioned
+	 *		at 0,0
+	 * Returns: 0 on success, -ENOENT if no such font
+	 */
+	int (*measure)(struct udevice *dev, const char *name, uint size,
+		       const char *text, struct vidconsole_bbox *bbox);
 };
 
 /* Get a pointer to the driver operations for a video console device */
@@ -215,6 +250,19 @@ int vidconsole_get_font(struct udevice *dev, int seq,
  */
 int vidconsole_select_font(struct udevice *dev, const char *name, uint size);
 
+/*
+ * vidconsole_measure() - Measuring the bounding box of some text
+ *
+ * @dev: Console device to use
+ * @name: Font name, NULL for default
+ * @size: Font size, ignored if @name is NULL
+ * @text: Text to measure
+ * @bbox: Returns nounding box of text
+ * Returns: 0 if OK, -ve on error
+ */
+int vidconsole_measure(struct udevice *dev, const char *name, uint size,
+		       const char *text, struct vidconsole_bbox *bbox);
+
 /**
  * vidconsole_push_colour() - Temporarily change the font colour
  *