console: Correct truetype spacing error

The putc_xy() method is supposed to return the amount of space used. The
existing implementation erroneously adds the previous sub-pixel position
to the returned value. This spaces out the characters very slightly more
than it should. It is seldom noticeable but it does make accurate
measurement of the text impossible.

Fix this minor but long-standing bug.

Fixes: a29b012037c ("video: Add a console driver that uses TrueType fonts")

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

diff --git a/drivers/video/console_truetype.c b/drivers/video/console_truetype.c
index 63d7557..6f3fc82 100644 (file)
--- a/drivers/video/console_truetype.c
+++ b/drivers/video/console_truetype.c
@@ -256,7 +256,7 @@ static int console_truetype_putc_xy(struct udevice *dev, uint x, uint y,
         */
        x_shift = xpos - (double)tt_floor(xpos);
        xpos += advance * met->scale;
-       width_frac = (int)VID_TO_POS(xpos);
+       width_frac = (int)VID_TO_POS(advance * met->scale);
        if (x + width_frac >= vc_priv->xsize_frac)
                return -EAGAIN;
 

diff --git a/test/dm/video.c b/test/dm/video.c
index 3077815..6d9c55c 100644 (file)
--- a/test/dm/video.c
+++ b/test/dm/video.c
@@ -556,7 +556,7 @@ static int dm_test_video_truetype(struct unit_test_state *uts)
        ut_assertok(video_get_nologo(uts, &dev));
        ut_assertok(uclass_get_device(UCLASS_VIDEO_CONSOLE, 0, &con));
        vidconsole_put_string(con, test_string);
-       ut_asserteq(12237, compress_frame_buffer(uts, dev));
+       ut_asserteq(12187, compress_frame_buffer(uts, dev));
 
        return 0;
 }
@@ -577,7 +577,7 @@ static int dm_test_video_truetype_scroll(struct unit_test_state *uts)
        ut_assertok(video_get_nologo(uts, &dev));
        ut_assertok(uclass_get_device(UCLASS_VIDEO_CONSOLE, 0, &con));
        vidconsole_put_string(con, test_string);
-       ut_asserteq(35030, compress_frame_buffer(uts, dev));
+       ut_asserteq(34481, compress_frame_buffer(uts, dev));
 
        return 0;
 }
@@ -598,7 +598,7 @@ static int dm_test_video_truetype_bs(struct unit_test_state *uts)
        ut_assertok(video_get_nologo(uts, &dev));
        ut_assertok(uclass_get_device(UCLASS_VIDEO_CONSOLE, 0, &con));
        vidconsole_put_string(con, test_string);
-       ut_asserteq(29018, compress_frame_buffer(uts, dev));
+       ut_asserteq(29579, compress_frame_buffer(uts, dev));
 
        return 0;
 }