[PATCH 06/10] lib/fonts: Refactor glyph-pattern helpers
From: Thomas Zimmermann <tzimmermann@suse.de>
Date: 2026-03-27 13:04:58
Also in:
dri-devel, linux-serial, lkml
Subsystem:
framebuffer console, library code, the rest · Maintainers:
Helge Deller, Thomas Zimmermann, Andrew Morton, Linus Torvalds
Change the signatures of the pattern helpers to align them with other font-glyph helpers: use the font_glyph_ prefix and pass the glyph buffer first. Calculating the position of the involved bit is somewhat obfuscated in the original implementation. Move it into the new helper __font_glphy_pos() and use the result as array index and bit position. Note that these bit helpers use a bit pitch, while other code uses a byte pitch. This is intentional an required here. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> --- lib/fonts/font_rotate.c | 45 ++++++++++++++++++++++++----------------- 1 file changed, 27 insertions(+), 18 deletions(-)
diff --git a/lib/fonts/font_rotate.c b/lib/fonts/font_rotate.c
index 3e0a19c889f3..cfaf5b98f49a 100644
--- a/lib/fonts/font_rotate.c
+++ b/lib/fonts/font_rotate.c@@ -15,21 +15,33 @@ #include "font.h" -static inline int pattern_test_bit(u32 x, u32 y, u32 pitch, const char *pat) +static unsigned int __font_glyph_pos(unsigned int x, unsigned int y, unsigned int bit_pitch, + unsigned int *bit) { - u32 tmp = (y * pitch) + x, index = tmp / 8, bit = tmp % 8; + unsigned int off = y * bit_pitch + x; + unsigned int bit_shift = off % 8; - pat += index; - return (*pat) & (0x80 >> bit); + *bit = 0x80 >> bit_shift; /* MSB has position 0, LSB has position 7 */ + + return off / 8; } -static inline void pattern_set_bit(u32 x, u32 y, u32 pitch, char *pat) +static bool font_glyph_test_bit(const unsigned char *glyph, unsigned int x, unsigned int y, + unsigned int bit_pitch) { - u32 tmp = (y * pitch) + x, index = tmp / 8, bit = tmp % 8; + unsigned int bit; + unsigned int i = __font_glyph_pos(x, y, bit_pitch, &bit); + + return glyph[i] & bit; +} - pat += index; +static void font_glyph_set_bit(unsigned char *glyph, unsigned int x, unsigned int y, + unsigned int bit_pitch) +{ + unsigned int bit; + unsigned int i = __font_glyph_pos(x, y, bit_pitch, &bit); - (*pat) |= 0x80 >> bit; + glyph[i] |= bit; } static inline void rotate_cw(const char *in, char *out, u32 width, u32 height)
@@ -42,9 +54,8 @@ static inline void rotate_cw(const char *in, char *out, u32 width, u32 height) for (i = 0; i < h; i++) { for (j = 0; j < w; j++) { - if (pattern_test_bit(j, i, width, in)) - pattern_set_bit(height - 1 - i - shift, j, - height, out); + if (font_glyph_test_bit(in, j, i, width)) + font_glyph_set_bit(out, height - 1 - i - shift, j, height); } } }
@@ -81,10 +92,9 @@ static inline void rotate_ud(const char *in, char *out, u32 width, u32 height) for (i = 0; i < height; i++) { for (j = 0; j < width - shift; j++) { - if (pattern_test_bit(j, i, width, in)) - pattern_set_bit(width - (1 + j + shift), - height - (1 + i), - width, out); + if (font_glyph_test_bit(in, j, i, width)) + font_glyph_set_bit(out, width - (1 + j + shift), + height - (1 + i), width); } } }
@@ -119,9 +129,8 @@ static inline void rotate_ccw(const char *in, char *out, u32 width, u32 height) for (i = 0; i < h; i++) { for (j = 0; j < w; j++) { - if (pattern_test_bit(j, i, width, in)) - pattern_set_bit(i, width - 1 - j - shift, - height, out); + if (font_glyph_test_bit(in, j, i, width)) + font_glyph_set_bit(out, i, width - 1 - j - shift, height); } } }
--
2.53.0