Commit 4ffd56e058e487f9806f4b1c77c73d292cabbd5c
2024-01-28T21:32:52
fixed horizontal advance and vertical baseline alignment for gl_text
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110
diff --git a/libc3/window/sdl2/gl_text.c b/libc3/window/sdl2/gl_text.c
index 7b1dd2a..2f0f92f 100644
--- a/libc3/window/sdl2/gl_text.c
+++ b/libc3/window/sdl2/gl_text.c
@@ -65,15 +65,18 @@ bool gl_text_render_to_texture (s_gl_text *text)
uw data_x;
uw data_y;
FT_Vector delta;
+ FT_Face face;
const s_gl_font *font;
FT_GlyphSlot glyph;
FT_UInt glyph_index;
uw i;
uw j;
- f32 max_height = 0.0;
+ uw max_ascent;
+ uw max_descent;
FT_UInt prev_glyph_index = 0;
s_str s;
- f32 total_width = 0.0;
+ f32 scale_y;
+ f32 x;
assert(text);
assert(text->font);
assert(text->texture);
@@ -83,50 +86,49 @@ bool gl_text_render_to_texture (s_gl_text *text)
glBindTexture(GL_TEXTURE_2D, text->texture);
assert(glGetError() == GL_NO_ERROR);
font = text->font;
+ face = font->ft_face;
s = text->str;
+ scale_y = face->size->metrics.y_scale / 65536.0;
+ max_ascent = (u32) (face->ascender * scale_y) >> 6;
+ max_descent = (u32) abs((int) (face->descender * scale_y)) >> 6;
+ data_w = 0;
+ data_h = max_ascent + max_descent;
while (str_read_character_utf8(&s, &c) > 0) {
- glyph_index = FT_Get_Char_Index(font->ft_face, c);
+ glyph_index = FT_Get_Char_Index(face, c);
if (prev_glyph_index && glyph_index) {
- FT_Get_Kerning(font->ft_face, prev_glyph_index, glyph_index,
+ FT_Get_Kerning(face, prev_glyph_index, glyph_index,
FT_KERNING_DEFAULT, &delta);
- total_width += delta.x >> 6;
+ data_w += delta.x >> 6;
}
- if (FT_Load_Glyph(font->ft_face, glyph_index, FT_LOAD_RENDER)) {
+ if (FT_Load_Glyph(face, glyph_index, FT_LOAD_RENDER)) {
err_write_1("gl_font_render_to_texture: failed to load glyph: ");
err_inspect_character(&c);
err_write_1("\n");
continue;
}
- glyph = font->ft_face->glyph;
- total_width += glyph->bitmap.width;
- if (glyph->bitmap.rows + glyph->bitmap_top > max_height)
- max_height = glyph->bitmap.rows + glyph->bitmap_top;
+ glyph = face->glyph;
+ data_w += glyph->metrics.horiAdvance >> 6;
prev_glyph_index = glyph_index;
}
- data_w = ceil(total_width);
- data_h = ceil(max_height);
data_size = data_w * data_h * 4;
data = calloc(1, data_size);
- f32 x = 0;
+ x = 0;
prev_glyph_index = 0;
s = text->str;
while (str_read_character_utf8(&s, &c) > 0) {
- glyph_index = FT_Get_Char_Index(font->ft_face, c);
-
- // Apply kerning (adjust spacing between characters)
+ glyph_index = FT_Get_Char_Index(face, c);
if (prev_glyph_index && glyph_index) {
FT_Vector delta;
- FT_Get_Kerning(font->ft_face, prev_glyph_index, glyph_index,
+ FT_Get_Kerning(face, prev_glyph_index, glyph_index,
FT_KERNING_DEFAULT, &delta);
x += delta.x >> 6;
}
- if (FT_Load_Glyph(font->ft_face, glyph_index, FT_LOAD_RENDER)) {
+ if (FT_Load_Glyph(face, glyph_index, FT_LOAD_RENDER))
continue;
- }
- glyph = font->ft_face->glyph;
+ glyph = face->glyph;
i = 0;
while (i < glyph->bitmap.rows) {
- data_y = i + glyph->bitmap_top;
+ data_y = data_h - 1 - i - max_ascent + glyph->bitmap_top;
//printf("\n");
j = 0;
while (j < glyph->bitmap.width) {
@@ -137,13 +139,13 @@ bool gl_text_render_to_texture (s_gl_text *text)
data_pixel[0] = 255;
data_pixel[1] = 255;
data_pixel[2] = 255;
- data_pixel[3] = (u8) value;
+ data_pixel[3] = value;
//printf("%s", (const char *[]) {" ", ".", ":", "#", "░", "▒", "▓", "█"}[value / 32]);
j++;
}
i++;
}
- x += glyph->bitmap.width;
+ x += glyph->metrics.horiAdvance >> 6;
prev_glyph_index = glyph_index;
}
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, data_w, data_h, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);