[PATCH 22/40] console: Allow measuring the bounding box of text
Simon Glass
sjg at chromium.org
Thu Jun 1 18:22:46 CEST 2023
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 at chromium.org>
---
drivers/video/console_truetype.c | 64 ++++++++++++++++++++++++++++++-
drivers/video/vidconsole-uclass.c | 22 +++++++++++
include/video_console.h | 48 +++++++++++++++++++++++
3 files changed, 132 insertions(+), 2 deletions(-)
diff --git a/drivers/video/console_truetype.c b/drivers/video/console_truetype.c
index 6f3fc82f9b05..288123a2e065 100644
--- a/drivers/video/console_truetype.c
+++ b/drivers/video/console_truetype.c
@@ -614,8 +614,8 @@ static void select_metrics(struct udevice *dev, struct console_tt_metrics *met)
vc_priv->tab_width_frac = VID_TO_POS(met->font_size) * 8 / 2;
}
-static int truetype_select_font(struct udevice *dev, const char *name,
- uint size)
+static int get_metrics(struct udevice *dev, const char *name, uint size,
+ struct console_tt_metrics **metp)
{
struct console_tt_priv *priv = dev_get_priv(dev);
struct console_tt_metrics *met;
@@ -653,11 +653,70 @@ static int truetype_select_font(struct udevice *dev, const char *name,
met = priv->metrics;
}
+ *metp = met;
+
+ return 0;
+}
+
+static int truetype_select_font(struct udevice *dev, const char *name,
+ uint size)
+{
+ struct console_tt_metrics *met;
+ int ret;
+
+ ret = get_metrics(dev, name, size, &met);
+ if (ret)
+ return log_msg_ret("sel", ret);
+
select_metrics(dev, met);
return 0;
}
+int truetype_measure(struct udevice *dev, const char *name, uint size,
+ const char *text, struct vidconsole_bbox *bbox)
+{
+ struct console_tt_metrics *met;
+ stbtt_fontinfo *font;
+ int lsb, advance;
+ const char *s;
+ int width;
+ int last;
+ int ret;
+
+ ret = get_metrics(dev, name, size, &met);
+ if (ret)
+ return log_msg_ret("sel", ret);
+
+ bbox->valid = false;
+ if (!*text)
+ return 0;
+
+ font = &met->font;
+ width = 0;
+ for (last = 0, s = text; *s; s++) {
+ int ch = *s;
+
+ /* Used kerning to fine-tune the position of this character */
+ if (last)
+ width += stbtt_GetCodepointKernAdvance(font, last, ch);
+
+ /* First get some basic metrics about this character */
+ stbtt_GetCodepointHMetrics(font, ch, &advance, &lsb);
+
+ width += advance;
+ last = ch;
+ }
+
+ bbox->valid = true;
+ bbox->x0 = 0;
+ bbox->y0 = 0;
+ bbox->x1 = tt_ceil((double)width * met->scale);
+ bbox->y1 = met->font_size;
+
+ return 0;
+}
+
const char *console_truetype_get_font_size(struct udevice *dev, uint *sizep)
{
struct console_tt_priv *priv = dev_get_priv(dev);
@@ -709,6 +768,7 @@ struct vidconsole_ops console_truetype_ops = {
.get_font = console_truetype_get_font,
.get_font_size = console_truetype_get_font_size,
.select_font = truetype_select_font,
+ .measure = truetype_measure,
};
U_BOOT_DRIVER(vidconsole_truetype) = {
diff --git a/drivers/video/vidconsole-uclass.c b/drivers/video/vidconsole-uclass.c
index 3f89537c47b7..05f930478096 100644
--- a/drivers/video/vidconsole-uclass.c
+++ b/drivers/video/vidconsole-uclass.c
@@ -596,6 +596,28 @@ int vidconsole_select_font(struct udevice *dev, const char *name, uint size)
return ops->select_font(dev, name, size);
}
+int vidconsole_measure(struct udevice *dev, const char *name, uint size,
+ const char *text, struct vidconsole_bbox *bbox)
+{
+ struct vidconsole_priv *priv = dev_get_uclass_priv(dev);
+ struct vidconsole_ops *ops = vidconsole_get_ops(dev);
+ int ret;
+
+ if (ops->select_font) {
+ ret = ops->measure(dev, name, size, text, bbox);
+ if (ret != -ENOSYS)
+ return ret;
+ }
+
+ bbox->valid = true;
+ bbox->x0 = 0;
+ bbox->y0 = 0;
+ bbox->x1 = priv->x_charsize * strlen(text);
+ bbox->y1 = priv->y_charsize;
+
+ return 0;
+}
+
void vidconsole_push_colour(struct udevice *dev, enum colour_idx fg,
enum colour_idx bg, struct vidconsole_colour *old)
{
diff --git a/include/video_console.h b/include/video_console.h
index 81d4c4d874df..2694e44f6ecf 100644
--- a/include/video_console.h
+++ b/include/video_console.h
@@ -82,6 +82,27 @@ struct vidconsole_colour {
u32 colour_bg;
};
+/**
+ * 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
*
@@ -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
*
--
2.41.0.rc0.172.g3f132b7071-goog
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