fix freetype font loading

This commit is contained in:
Matthew 2025-08-27 07:02:44 +10:00
parent f211a29857
commit 69f5cd1a76

125
fonts.d
View File

@ -88,6 +88,19 @@ CloseFont(FontFace font)
}
}
i32
Float26(f32 f)
{
return cast(i32)round(cast(f32)(1 << 6) * f);
}
u8
DeMultiply(u8 color, u8 alpha)
{
u32 v = cast(u32)(255.0 * cast(f32)(color) / cast(f32)(alpha + f32.epsilon) + 0.5);
return v > 255 ? 255 : cast(u8)v;
}
FontAtlasBuf
CreateAtlas(Arena* arena, FontFace font, f32 size, u32 dimension)
{
@ -105,8 +118,6 @@ CreateAtlas(Arena* arena, FontFace font, f32 size, u32 dimension)
// TODO: proper packing algorithm
if (font != null)
{
FT_Set_Pixel_Sizes(font, 0, cast(FT_UInt)((96.0/72.0) * size));
i64 f_ascent = cast(i64)(font.size.metrics.ascender >> 6);
i64 f_descent = cast(i64)(font.size.metrics.descender >> 6);
i64 f_height = cast(i64)(font.size.metrics.height >> 6);
@ -116,8 +127,13 @@ CreateAtlas(Arena* arena, FontFace font, f32 size, u32 dimension)
u32 current_h = 0;
u32 count = 0;
i32 font_size = Float26(size);
FT_Library_SetLcdFilter(FT_LIB, FT_LCD_FILTER_NONE);
foreach(FT_ULong char_code; 0 .. 0x7F)
{
FT_Set_Char_Size(font, font_size, 0, 0, 0);
FT_Error res = FT_Load_Char(font, char_code, cast(FT_Int32)FT_LOAD_RENDER);
if (res != 0)
{
@ -139,16 +155,16 @@ CreateAtlas(Arena* arena, FontFace font, f32 size, u32 dimension)
count += 1;
}
max_w = 0;
max_h = 0;
const u32 PADDING = 2;
max_w = PADDING;
max_h = PADDING;
current_h = 0;
count = 0;
u32 font_w = font.size.metrics.x_ppem;
u32 font_h = font.size.metrics.y_ppem;
foreach(FT_ULong char_code; 0 .. 0x7F)
{
FT_Set_Char_Size(font, font_size, 0, 0, 0);
FT_Error res = FT_Load_Char(font, char_code, cast(FT_Int32)FT_LOAD_RENDER);
if (res != 0)
{
@ -162,24 +178,88 @@ CreateAtlas(Arena* arena, FontFace font, f32 size, u32 dimension)
if (max_w + bmp.rows > dimension)
{
max_h += current_h;
max_w = 0;
max_h += cast(u32)(size) + PADDING;
max_w = PADDING;
}
i32 x, y;
foreach(r; 0 .. bmp.rows)
switch(bmp.pixel_mode)
{
y = cast(i32)(max_h + r);
foreach(c; 0 .. bmp.width)
{
x = max_w + c;
u64 offset = (y*dimension + x) * 4;
case FT_PIXEL_MODE_BGRA:
{
i32 x, y;
foreach(r; 0 .. bmp.rows)
{
y = cast(i32)(max_h + r);
foreach(c; 0 .. bmp.width)
{
x = max_w + c;
u64 offset = (y*dimension + x) * 4;
atlas.data[offset+0] = 255;
atlas.data[offset+1] = 255;
atlas.data[offset+2] = 255;
atlas.data[offset+3] = bmp.buffer[r*bmp.pitch + c];
}
u8 p_b = bmp.buffer[offset+0];
u8 p_g = bmp.buffer[offset+1];
u8 p_r = bmp.buffer[offset+2];
u8 p_a = bmp.buffer[offset+3];
atlas.data[offset+0] = DeMultiply(p_r, p_a);
atlas.data[offset+1] = DeMultiply(p_b, p_a);
atlas.data[offset+2] = DeMultiply(p_g, p_a);
atlas.data[offset+3] = p_a;
}
}
} break;
case FT_PIXEL_MODE_MONO:
{
u32 pitch = bmp.pitch;
u8* buf = bmp.buffer;
i32 x, y;
foreach(r; 0 .. bmp.rows)
{
u8 bits = 0;
u8* buf_ptr = buf;
y = cast(i32)(max_h + r);
foreach(c; 0 .. bmp.width)
{
if ((c & 7) == 0)
{
bits = *buf_ptr;
buf_ptr += 1;
}
x = max_w + c;
u64 offset = (y*dimension + x) * 4;
atlas.data[offset+0] = 255;
atlas.data[offset+1] = 255;
atlas.data[offset+2] = 255;
atlas.data[offset+3] = (bits & 0x80) ? 255 : 0;
bits <<= 1;
}
buf += pitch;
}
} break;
case FT_PIXEL_MODE_GRAY:
{
i32 x, y;
foreach(r; 0 .. bmp.rows)
{
y = cast(i32)(max_h + r);
foreach(c; 0 .. bmp.width)
{
x = max_w + c;
u64 offset = (y*dimension + x) * 4;
atlas.data[offset+0] = 255;
atlas.data[offset+1] = 255;
atlas.data[offset+2] = 255;
atlas.data[offset+3] = bmp.buffer[r*bmp.pitch + c];
}
}
} break;
default:
assert(false, "Unknown pixel_mode value");
break;
}
Glyph* g = atlas.atlas.glyphs.ptr + char_code;
@ -196,7 +276,7 @@ CreateAtlas(Arena* arena, FontFace font, f32 size, u32 dimension)
g.atlas_bottom = max_h + bmp.rows;
g.atlas_right = max_w + bmp.width;
max_w += bmp.width;
max_w += bmp.width + PADDING;
current_h = bmp.rows > current_h ? bmp.rows : current_h;
count += 1;
@ -206,3 +286,4 @@ CreateAtlas(Arena* arena, FontFace font, f32 size, u32 dimension)
return atlas;
}