[U-Boot] [PATCH 04/19] video: Use fractional units for X coordinates

Simon Glass
2016-01-15T01:10:37Z

With anti-aliased fonts we need a more fine-grained horizontal position
than a single pixel. Characters can be positioned to start part-way through
a pixel, with anti-aliasing (greyscale edges) taking care of the visual
effect.

To cope with this, use fractional units (1/256 pixel) for horizontal
positions in the text console.

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

drivers/video/console_normal.c | 24 ++++++++++++--
drivers/video/console_rotate.c | 66 +++++++++++++++++++++++++++++----------
drivers/video/vidconsole-uclass.c | 57 +++++++++++++++++++--------------
include/video_console.h | 40 ++++++++++++++++++------
test/dm/video.c | 4 +--
5 files changed, 138 insertions(+), 53 deletions(-)

diff --git a/drivers/video/console_normal.c b/drivers/video/console_normal.c
index d1031c8..89a55dd 100644
--- a/drivers/video/console_normal.c
+++ b/drivers/video/console_normal.c
@@ -71,13 +71,18 @@ static int console_normal_move_rows(struct udevice *dev, uint rowdst,
return 0;
}

-static int console_normal_putc_xy(struct udevice *dev, uint x, uint y, char ch)
+static int console_normal_putc_xy(struct udevice *dev, uint x_frac, uint y,
+ char ch)
{
+ struct vidconsole_priv *vc_priv = dev_get_uclass_priv(dev);
struct udevice *vid = dev->parent;
struct video_priv *vid_priv = dev_get_uclass_priv(vid);
int i, row;
void *line = vid_priv->fb + y * vid_priv->line_length +
- x * VNBYTES(vid_priv->bpix);
+ VID_TO_PIXEL(x_frac) * VNBYTES(vid_priv->bpix);
+
+ if (x_frac + VID_TO_POS(vc_priv->x_charsize) > vc_priv->xsize_frac)
+ return -EAGAIN;

for (row = 0; row < VIDEO_FONT_HEIGHT; row++) {
uchar bits = video_fontdata[ch * VIDEO_FONT_HEIGHT + row];
@@ -125,6 +130,20 @@ static int console_normal_putc_xy(struct udevice *dev, uint x, uint y, char ch)
line += vid_priv->line_length;
}

+ return VID_TO_POS(VIDEO_FONT_WIDTH);
+}
+
+static int console_normal_probe(struct udevice *dev)
+{
+ struct vidconsole_priv *vc_priv = dev_get_uclass_priv(dev);
+ struct udevice *vid_dev = dev->parent;
+ struct video_priv *vid_priv = dev_get_uclass_priv(vid_dev);
+
+ vc_priv->x_charsize = VIDEO_FONT_WIDTH;
+ vc_priv->y_charsize = VIDEO_FONT_HEIGHT;
+ vc_priv->cols = vid_priv->xsize / VIDEO_FONT_WIDTH;
+ vc_priv->rows = vid_priv->ysize / VIDEO_FONT_HEIGHT;
+
return 0;
}

@@ -138,4 +157,5 @@ U_BOOT_DRIVER(vidconsole_normal) = {
.name = "vidconsole0",
.id = UCLASS_VIDEO_CONSOLE,
.ops = &console_normal_ops,
+ .probe = console_normal_probe,
};
diff --git a/drivers/video/console_rotate.c b/drivers/video/console_rotate.c
index 4c5c4ef..227141d 100644
--- a/drivers/video/console_rotate.c
+++ b/drivers/video/console_rotate.c
@@ -82,17 +82,22 @@ static int console_move_rows_1(struct udevice *dev, uint rowdst, uint rowsrc,
return 0;
}

-static int console_putc_xy_1(struct udevice *dev, uint x, uint y, char ch)
+static int console_putc_xy_1(struct udevice *dev, uint x_frac, uint y, char ch)
{
+ struct vidconsole_priv *vc_priv = dev_get_uclass_priv(dev);
struct udevice *vid = dev->parent;
struct video_priv *vid_priv = dev_get_uclass_priv(vid);
int pbytes = VNBYTES(vid_priv->bpix);
int i, col;
int mask = 0x80;
- void *line = vid_priv->fb + (x + 1) * vid_priv->line_length -
- (y + 1) * pbytes;
+ void *line;
uchar *pfont = video_fontdata + ch * VIDEO_FONT_HEIGHT;

+ line = vid_priv->fb + (VID_TO_PIXEL(x_frac) + 1) *
+ vid_priv->line_length - (y + 1) * pbytes;
+ if (x_frac + VID_TO_POS(vc_priv->x_charsize) > vc_priv->xsize_frac)
+ return -EAGAIN;
+
for (col = 0; col < VIDEO_FONT_HEIGHT; col++) {
switch (vid_priv->bpix) {
#ifdef CONFIG_VIDEO_BPP8
@@ -135,7 +140,7 @@ static int console_putc_xy_1(struct udevice *dev, uint x, uint y, char ch)
mask >>= 1;
}

- return 0;
+ return VID_TO_POS(VIDEO_FONT_WIDTH);
}

@@ -201,16 +206,21 @@ static int console_move_rows_2(struct udevice *dev, uint rowdst, uint rowsrc,
return 0;
}

-static int console_putc_xy_2(struct udevice *dev, uint x, uint y, char ch)
+static int console_putc_xy_2(struct udevice *dev, uint x_frac, uint y, char ch)
{
+ struct vidconsole_priv *vc_priv = dev_get_uclass_priv(dev);
struct udevice *vid = dev->parent;
struct video_priv *vid_priv = dev_get_uclass_priv(vid);
int i, row;
void *line;

- line = vid_priv->fb + (vid_priv->ysize - y - 1) * vid_priv->line_length +
- (vid_priv->xsize - x - VIDEO_FONT_WIDTH - 1) *
- VNBYTES(vid_priv->bpix);
+ if (x_frac + VID_TO_POS(vc_priv->x_charsize) > vc_priv->xsize_frac)
+ return -EAGAIN;
+
+ line = vid_priv->fb + (vid_priv->ysize - y - 1) *
+ vid_priv->line_length +
+ (vid_priv->xsize - VID_TO_PIXEL(x_frac) -
+ VIDEO_FONT_WIDTH - 1) * VNBYTES(vid_priv->bpix);

for (row = 0; row < VIDEO_FONT_HEIGHT; row++) {
uchar bits = video_fontdata[ch * VIDEO_FONT_HEIGHT + row];
@@ -258,7 +268,7 @@ static int console_putc_xy_2(struct udevice *dev, uint x, uint y, char ch)
line -= vid_priv->line_length;
}

- return 0;
+ return VID_TO_POS(VIDEO_FONT_WIDTH);
}

static int console_set_row_3(struct udevice *dev, uint row, int clr)
@@ -328,17 +338,22 @@ static int console_move_rows_3(struct udevice *dev, uint rowdst, uint rowsrc,
return 0;
}

-static int console_putc_xy_3(struct udevice *dev, uint x, uint y, char ch)
+static int console_putc_xy_3(struct udevice *dev, uint x_frac, uint y, char ch)
{
+ struct vidconsole_priv *vc_priv = dev_get_uclass_priv(dev);
struct udevice *vid = dev->parent;
struct video_priv *vid_priv = dev_get_uclass_priv(vid);
int pbytes = VNBYTES(vid_priv->bpix);
int i, col;
int mask = 0x80;
- void *line = vid_priv->fb + (vid_priv->ysize - x - 1) *
+ void *line = vid_priv->fb +
+ (vid_priv->ysize - VID_TO_PIXEL(x_frac) - 1) *
vid_priv->line_length + y * pbytes;
uchar *pfont = video_fontdata + ch * VIDEO_FONT_HEIGHT;

+ if (x_frac + VID_TO_POS(vc_priv->x_charsize) > vc_priv->xsize_frac)
+ return -EAGAIN;
+
for (col = 0; col < VIDEO_FONT_HEIGHT; col++) {
switch (vid_priv->bpix) {
#ifdef CONFIG_VIDEO_BPP8
@@ -381,17 +396,35 @@ static int console_putc_xy_3(struct udevice *dev, uint x, uint y, char ch)
mask >>= 1;
}

- return 0;
+ return VID_TO_POS(VIDEO_FONT_WIDTH);
}

+static int console_probe_2(struct udevice *dev)
+{
+ struct vidconsole_priv *vc_priv = dev_get_uclass_priv(dev);
+ struct udevice *vid_dev = dev->parent;
+ struct video_priv *vid_priv = dev_get_uclass_priv(vid_dev);
+
+ vc_priv->x_charsize = VIDEO_FONT_WIDTH;
+ vc_priv->y_charsize = VIDEO_FONT_HEIGHT;
+ vc_priv->cols = vid_priv->xsize / VIDEO_FONT_WIDTH;
+ vc_priv->rows = vid_priv->ysize / VIDEO_FONT_HEIGHT;
+
+ return 0;
+}
+
static int console_probe_1_3(struct udevice *dev)
{
- struct vidconsole_priv *priv = dev_get_uclass_priv(dev);
- struct video_priv *vid_priv = dev_get_uclass_priv(dev->parent);
+ struct vidconsole_priv *vc_priv = dev_get_uclass_priv(dev);
+ struct udevice *vid_dev = dev->parent;
+ struct video_priv *vid_priv = dev_get_uclass_priv(vid_dev);

- priv->cols = vid_priv->ysize / VIDEO_FONT_WIDTH;
- priv->rows = vid_priv->xsize / VIDEO_FONT_HEIGHT;
+ vc_priv->x_charsize = VIDEO_FONT_WIDTH;
+ vc_priv->y_charsize = VIDEO_FONT_HEIGHT;
+ vc_priv->cols = vid_priv->ysize / VIDEO_FONT_WIDTH;
+ vc_priv->rows = vid_priv->xsize / VIDEO_FONT_HEIGHT;
+ vc_priv->xsize_frac = VID_TO_POS(vid_priv->ysize);

return 0;
}
@@ -425,6 +458,7 @@ U_BOOT_DRIVER(vidconsole_2) = {
.name = "vidconsole2",
.id = UCLASS_VIDEO_CONSOLE,
.ops = &console_ops_2,
+ .probe = console_probe_2,
};

U_BOOT_DRIVER(vidconsole_3) = {
diff --git a/drivers/video/vidconsole-uclass.c b/drivers/video/vidconsole-uclass.c
index a4c919e..da92ee8 100644
--- a/drivers/video/vidconsole-uclass.c
+++ b/drivers/video/vidconsole-uclass.c
@@ -52,14 +52,14 @@ static void vidconsole_back(struct udevice *dev)
{
struct vidconsole_priv *priv = dev_get_uclass_priv(dev);

- if (--priv->curr_col < 0) {
- priv->curr_col = priv->cols - 1;
- if (--priv->curr_row < 0)
- priv->curr_row = 0;
+ priv->xcur_frac -= VID_TO_POS(priv->x_charsize);
+ if (priv->xcur_frac < 0) {
+ priv->xcur_frac = (priv->cols - 1) *
+ VID_TO_POS(priv->x_charsize);
+ priv->ycur -= priv->y_charsize;
+ if (priv->ycur < 0)
+ priv->ycur = 0;
}
-
- vidconsole_putc_xy(dev, priv->curr_col * VIDEO_FONT_WIDTH,
- priv->curr_row * VIDEO_FONT_HEIGHT, ' ');
}

/* Move to a newline, scrolling the display if necessary */
@@ -71,15 +71,16 @@ static void vidconsole_newline(struct udevice *dev)
const int rows = CONFIG_CONSOLE_SCROLL_LINES;
int i;

- priv->curr_col = 0;
+ priv->xcur_frac = 0;
+ priv->ycur += priv->y_charsize;

/* Check if we need to scroll the terminal */
- if (++priv->curr_row >= priv->rows) {
+ if ((priv->ycur + priv->y_charsize) / priv->y_charsize > priv->rows) {
vidconsole_move_rows(dev, 0, rows, priv->rows - rows);
for (i = 0; i < rows; i++)
vidconsole_set_row(dev, priv->rows - i - 1,
vid_priv->colour_bg);
- priv->curr_row -= rows;
+ priv->ycur -= rows * priv->y_charsize;
}
video_sync(dev->parent);
}
@@ -91,16 +92,16 @@ int vidconsole_put_char(struct udevice *dev, char ch)

switch (ch) {
case '\r':
- priv->curr_col = 0;
+ priv->xcur_frac = 0;
break;
case '\n':
vidconsole_newline(dev);
break;
case '\t': /* Tab (8 chars alignment) */
- priv->curr_col += 8;
- priv->curr_col &= ~7;
+ priv->xcur_frac = ((priv->xcur_frac / priv->tab_width_frac)
+ + 1) * priv->tab_width_frac;

- if (priv->curr_col >= priv->cols)
+ if (priv->xcur_frac >= priv->xsize_frac)
vidconsole_newline(dev);
break;
case '\b':
@@ -112,13 +113,16 @@ int vidconsole_put_char(struct udevice *dev, char ch)
* colour depth. Check this and return an error to help with
* diagnosis.
*/
- ret = vidconsole_putc_xy(dev,
- priv->curr_col * VIDEO_FONT_WIDTH,
- priv->curr_row * VIDEO_FONT_HEIGHT,
- ch);
- if (ret)
+ ret = vidconsole_putc_xy(dev, priv->xcur_frac, priv->ycur, ch);
+ if (ret == -EAGAIN) {
+ vidconsole_newline(dev);
+ ret = vidconsole_putc_xy(dev, priv->xcur_frac,
+ priv->ycur, ch);
+ }
+ if (ret < 0)
return ret;
- if (++priv->curr_col >= priv->cols)
+ priv->xcur_frac += ret;
+ if (priv->xcur_frac >= priv->xsize_frac)
vidconsole_newline(dev);
break;
}
@@ -149,8 +153,7 @@ static int vidconsole_pre_probe(struct udevice *dev)
struct udevice *vid = dev->parent;
struct video_priv *vid_priv = dev_get_uclass_priv(vid);

- priv->rows = vid_priv->ysize / VIDEO_FONT_HEIGHT;
- priv->cols = vid_priv->xsize / VIDEO_FONT_WIDTH;
+ priv->xsize_frac = VID_TO_POS(vid_priv->xsize);

return 0;
}
@@ -162,12 +165,16 @@ static int vidconsole_post_probe(struct udevice *dev)
struct stdio_dev *sdev = &priv->sdev;
int ret;

+ if (!priv->tab_width_frac)
+ priv->tab_width_frac = VID_TO_POS(priv->x_charsize) * 8;
+
if (dev->seq) {
snprintf(sdev->name, sizeof(sdev->name), "vidconsole%d",
dev->seq);
} else {
strcpy(sdev->name, "vidconsole");
}
+
sdev->flags = DEV_FLAGS_OUTPUT;
sdev->putc = vidconsole_putc;
sdev->puts = vidconsole_puts;
@@ -190,9 +197,11 @@ UCLASS_DRIVER(vidconsole) = {
void vidconsole_position_cursor(struct udevice *dev, unsigned col, unsigned row)
{
struct vidconsole_priv *priv = dev_get_uclass_priv(dev);
+ struct udevice *vid_dev = dev->parent;
+ struct video_priv *vid_priv = dev_get_uclass_priv(vid_dev);

- priv->curr_col = min_t(short, col, priv->cols - 1);
- priv->curr_row = min_t(short, row, priv->rows - 1);
+ priv->xcur_frac = VID_TO_POS(min_t(short, col, vid_priv->xsize - 1));
+ priv->ycur = min_t(short, row, vid_priv->ysize - 1);
}

static int do_video_setcursor(cmd_tbl_t *cmdtp, int flag, int argc,
diff --git a/include/video_console.h b/include/video_console.h
index d4acbc8..2f7012e 100644
--- a/include/video_console.h
+++ b/include/video_console.h
@@ -7,21 +7,37 @@
#ifndef __video_console_h
#define __video_console_h

+#define VID_FRAC_DIV 256
+
+#define VID_TO_PIXEL(x) ((x) / VID_FRAC_DIV)
+#define VID_TO_POS(x) ((x) * VID_FRAC_DIV)
+
/**
* struct vidconsole_priv - uclass-private data about a console device
*
+ * Drivers must set up @rows, @cols, @x_charsize, @y_charsize in their probe()
+ * method. Drivers may set up @xstart_frac if desired.
+ *
* @sdev: stdio device, acting as an output sink
- * @curr_col: Current text column (0=left)
- * @curr_row: Current row (0=top)
+ * @xcur_frac: Current X position, in fractional units (VID_TO_POS(x))
+ * @curr_row: Current Y position in pixels (0=top)
* @rows: Number of text rows
* @cols: Number of text columns
+ * @x_charsize: Character width in pixels
+ * @y_charsize: Character height in pixels
+ * @tab_width_frac: Tab width in fractional units
+ * @xsize_frac: Width of the display in fractional units
*/
struct vidconsole_priv {
struct stdio_dev sdev;
- int curr_col;
- int curr_row;
+ int xcur_frac;
+ int ycur;
int rows;
int cols;
+ int x_charsize;
+ int y_charsize;
+ int tab_width_frac;
+ int xsize_frac;
};

/**
@@ -36,12 +52,15 @@ struct vidconsole_ops {
* putc_xy() - write a single character to a position
*
* @dev: Device to write to
- * @x: Pixel X position (0=left-most pixel)
+ * @x_frac: Fractional pixel X position (0=left-most pixel) which
+ * is the X position multipled by VID_FRAC_DIV.
* @y: Pixel Y position (0=top-most pixel)
* @ch: Character to write
- * @return 0 if OK, -ve on error
+ * @return number of fractional pixels that the cursor should move,
+ * if all is OK, -EAGAIN if we ran out of space on this line, other -ve
+ * on error
*/
- int (*putc_xy)(struct udevice *dev, uint x, uint y, char ch);
+ int (*putc_xy)(struct udevice *dev, uint x_frac, uint y, char ch);

/**
* move_rows() - Move text rows from one place to another
@@ -75,10 +94,13 @@ struct vidconsole_ops {
* vidconsole_putc_xy() - write a single character to a position
*
* @dev: Device to write to
- * @x: Pixel X position (0=left-most pixel)
+ * @x_frac: Fractional pixel X position (0=left-most pixel) which
+ * is the X position multipled by VID_FRAC_DIV.
* @y: Pixel Y position (0=top-most pixel)
* @ch: Character to write
- * @return 0 if OK, -ve on error
+ * @return number of fractional pixels that the cursor should move,
+ * if all is OK, -EAGAIN if we ran out of space on this line, other -ve
+ * on error
*/
int vidconsole_putc_xy(struct udevice *dev, uint x, uint y, char ch);

diff --git a/test/dm/video.c b/test/dm/video.c
index 52aba2e..3540271 100644
--- a/test/dm/video.c
+++ b/test/dm/video.c
@@ -106,14 +106,14 @@ static int dm_test_video_text(struct unit_test_state *uts)
ut_asserteq(46, compress_frame_buffer(dev));

for (i = 0; i < 20; i++)
- vidconsole_putc_xy(con, i * 8, 0, ' ' + i);
+ vidconsole_putc_xy(con, VID_TO_POS(i * 8), 0, ' ' + i);
ut_asserteq(273, compress_frame_buffer(dev));

vidconsole_set_row(con, 0, WHITE);
ut_asserteq(46, compress_frame_buffer(dev));

for (i = 0; i < 20; i++)
- vidconsole_putc_xy(con, i * 8, 0, ' ' + i);
+ vidconsole_putc_xy(con, VID_TO_POS(i * 8), 0, ' ' + i);
ut_asserteq(273, compress_frame_buffer(dev));

return 0;
--
2.6.0.rc2.230.g3dd15c0