video: Use fractional units for X coordinates

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>
[agust: rebased]
Signed-off-by: Anatolij Gustschin <agust@denx.de>

diff --git a/drivers/video/console_normal.c b/drivers/video/console_normal.c
index d1031c8..89a55dd 100644 (file)
--- 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 ebb31d8..227141d 100644 (file)
--- 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);
 }
 
 
@@ -201,17 +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;
 
+       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 - x - VIDEO_FONT_WIDTH - 1) *
-               VNBYTES(vid_priv->bpix);
+                       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];
@@ -259,7 +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)
@@ -329,17 +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
@@ -382,17 +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;
 }
@@ -426,6 +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 706a189..3145fd8 100644 (file)
--- 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;
        }
@@ -148,8 +152,7 @@ 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;
 }
@@ -161,12 +164,16 @@ 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;
@@ -189,9 +196,11 @@ 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 c0fc792..eeba368 100644 (file)
--- 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 9f5e7fc..be94633 100644 (file)
--- 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;