mirror of
https://github.com/Ed94/VEFontCache-Odin.git
synced 2025-08-05 22:42:43 -07:00
455 lines
12 KiB
Odin
455 lines
12 KiB
Odin
package vefontcache
|
|
|
|
/*
|
|
Notes:
|
|
|
|
Freetype will do memory allocations and has an interface the user can implement.
|
|
That interface is not exposed from this parser but could be added to parser_init.
|
|
|
|
STB_Truetype has macros for its allocation unfortuantely
|
|
*/
|
|
|
|
import "base:runtime"
|
|
import "core:c"
|
|
import "core:math"
|
|
import "core:slice"
|
|
import stbtt "vendor:stb/truetype"
|
|
import freetype "thirdparty:freetype"
|
|
|
|
ParserKind :: enum u32 {
|
|
STB_TrueType,
|
|
Freetype,
|
|
}
|
|
|
|
ParserFontInfo :: struct {
|
|
label : string,
|
|
kind : ParserKind,
|
|
using _ : struct #raw_union {
|
|
stbtt_info : stbtt.fontinfo,
|
|
freetype_info : freetype.Face
|
|
},
|
|
data : []byte,
|
|
}
|
|
|
|
GlyphVertType :: enum u8 {
|
|
None,
|
|
Move = 1,
|
|
Line,
|
|
Curve,
|
|
Cubic,
|
|
}
|
|
|
|
// Based directly off of stb_truetype's vertex
|
|
ParserGlyphVertex :: struct {
|
|
x, y : i16,
|
|
contour_x0, contour_y0 : i16,
|
|
contour_x1, contour_y1 : i16,
|
|
type : GlyphVertType,
|
|
padding : u8,
|
|
}
|
|
// A shape can be a dynamic array free_type or an opaque set of data handled by stb_truetype
|
|
ParserGlyphShape :: [dynamic]ParserGlyphVertex
|
|
|
|
ParserContext :: struct {
|
|
kind : ParserKind,
|
|
ft_library : freetype.Library,
|
|
|
|
// fonts : HMapChained(ParserFontInfo),
|
|
}
|
|
|
|
parser_init :: proc( ctx : ^ParserContext, kind : ParserKind )
|
|
{
|
|
switch kind
|
|
{
|
|
case .Freetype:
|
|
result := freetype.init_free_type( & ctx.ft_library )
|
|
assert( result == freetype.Error.Ok, "VEFontCache.parser_init: Failed to initialize freetype" )
|
|
|
|
case .STB_TrueType:
|
|
// Do nothing intentional
|
|
}
|
|
|
|
ctx.kind = kind
|
|
|
|
// error : AllocatorError
|
|
// ctx.fonts, error = make( HMapChained(ParserFontInfo), 256 )
|
|
// assert( error == .None, "VEFontCache.parser_init: Failed to allocate fonts array" )
|
|
}
|
|
|
|
parser_shutdown :: proc( ctx : ^ParserContext ) {
|
|
// TODO(Ed): Implement
|
|
}
|
|
|
|
parser_load_font :: proc( ctx : ^ParserContext, label : string, data : []byte ) -> (font : ParserFontInfo)
|
|
{
|
|
// key := font_key_from_label(label)
|
|
// font = get( ctx.fonts, key )
|
|
// if font != nil do return
|
|
|
|
// error : AllocatorError
|
|
// font, error = set( ctx.fonts, key, ParserFontInfo {} )
|
|
// assert( error == .None, "VEFontCache.parser_load_font: Failed to set a new parser font info" )
|
|
switch ctx.kind
|
|
{
|
|
case .Freetype:
|
|
error := freetype.new_memory_face( ctx.ft_library, raw_data(data), cast(i32) len(data), 0, & font.freetype_info )
|
|
if error != .Ok do return
|
|
|
|
case .STB_TrueType:
|
|
success := stbtt.InitFont( & font.stbtt_info, raw_data(data), 0 )
|
|
if ! success do return
|
|
}
|
|
|
|
font.label = label
|
|
font.data = data
|
|
font.kind = ctx.kind
|
|
return
|
|
}
|
|
|
|
parser_unload_font :: proc( font : ^ParserFontInfo )
|
|
{
|
|
switch font.kind {
|
|
case .Freetype:
|
|
error := freetype.done_face( font.freetype_info )
|
|
assert( error == .Ok, "VEFontCache.parser_unload_font: Failed to unload freetype face" )
|
|
|
|
case .STB_TrueType:
|
|
// Do Nothing
|
|
}
|
|
}
|
|
|
|
parser_find_glyph_index :: #force_inline proc "contextless" ( font : ^ParserFontInfo, codepoint : rune ) -> (glyph_index : Glyph)
|
|
{
|
|
switch font.kind
|
|
{
|
|
case .Freetype:
|
|
glyph_index = transmute(Glyph) freetype.get_char_index( font.freetype_info, transmute(u32) codepoint )
|
|
return
|
|
|
|
case .STB_TrueType:
|
|
glyph_index = transmute(Glyph) stbtt.FindGlyphIndex( & font.stbtt_info, codepoint )
|
|
return
|
|
}
|
|
return Glyph(-1)
|
|
}
|
|
|
|
parser_free_shape :: proc( font : ^ParserFontInfo, shape : ParserGlyphShape )
|
|
{
|
|
switch font.kind
|
|
{
|
|
case .Freetype:
|
|
delete(shape)
|
|
|
|
case .STB_TrueType:
|
|
stbtt.FreeShape( & font.stbtt_info, transmute( [^]stbtt.vertex) raw_data(shape) )
|
|
}
|
|
}
|
|
|
|
parser_get_codepoint_horizontal_metrics :: #force_inline proc "contextless" ( font : ^ParserFontInfo, codepoint : rune ) -> ( advance, to_left_side_glyph : i32 )
|
|
{
|
|
switch font.kind
|
|
{
|
|
case .Freetype:
|
|
glyph_index := transmute(Glyph) freetype.get_char_index( font.freetype_info, transmute(u32) codepoint )
|
|
if glyph_index != 0
|
|
{
|
|
freetype.load_glyph( font.freetype_info, c.uint(codepoint), { .No_Bitmap, .No_Hinting, .No_Scale } )
|
|
advance = i32(font.freetype_info.glyph.advance.x) >> 6
|
|
to_left_side_glyph = i32(font.freetype_info.glyph.metrics.hori_bearing_x) >> 6
|
|
}
|
|
else
|
|
{
|
|
advance = 0
|
|
to_left_side_glyph = 0
|
|
}
|
|
|
|
case .STB_TrueType:
|
|
stbtt.GetCodepointHMetrics( & font.stbtt_info, codepoint, & advance, & to_left_side_glyph )
|
|
}
|
|
return
|
|
}
|
|
|
|
parser_get_codepoint_kern_advance :: #force_inline proc "contextless" ( font : ^ParserFontInfo, prev_codepoint, codepoint : rune ) -> i32
|
|
{
|
|
switch font.kind
|
|
{
|
|
case .Freetype:
|
|
prev_glyph_index := transmute(Glyph) freetype.get_char_index( font.freetype_info, transmute(u32) prev_codepoint )
|
|
glyph_index := transmute(Glyph) freetype.get_char_index( font.freetype_info, transmute(u32) codepoint )
|
|
if prev_glyph_index != 0 && glyph_index != 0
|
|
{
|
|
kerning : freetype.Vector
|
|
font.freetype_info.driver.clazz.get_kerning( font.freetype_info, transmute(u32) prev_codepoint, transmute(u32) codepoint, & kerning )
|
|
}
|
|
|
|
case .STB_TrueType:
|
|
kern := stbtt.GetCodepointKernAdvance( & font.stbtt_info, prev_codepoint, codepoint )
|
|
return kern
|
|
}
|
|
return -1
|
|
}
|
|
|
|
parser_get_font_vertical_metrics :: #force_inline proc "contextless" ( font : ^ParserFontInfo ) -> (ascent, descent, line_gap : i32 )
|
|
{
|
|
switch font.kind
|
|
{
|
|
case .Freetype:
|
|
info := font.freetype_info
|
|
ascent = i32(info.ascender)
|
|
descent = i32(info.descender)
|
|
line_gap = i32(info.height) - (ascent - descent)
|
|
|
|
case .STB_TrueType:
|
|
stbtt.GetFontVMetrics( & font.stbtt_info, & ascent, & descent, & line_gap )
|
|
}
|
|
return
|
|
}
|
|
|
|
parser_get_glyph_box :: #force_inline proc ( font : ^ParserFontInfo, glyph_index : Glyph ) -> (bounds_0, bounds_1 : Vec2i)
|
|
{
|
|
switch font.kind
|
|
{
|
|
case .Freetype:
|
|
freetype.load_glyph( font.freetype_info, c.uint(glyph_index), { .No_Bitmap, .No_Hinting, .No_Scale } )
|
|
|
|
metrics := font.freetype_info.glyph.metrics
|
|
|
|
bounds_0 = {i32(metrics.hori_bearing_x), i32(metrics.hori_bearing_y - metrics.height)}
|
|
bounds_1 = {i32(metrics.hori_bearing_x + metrics.width), i32(metrics.hori_bearing_y)}
|
|
|
|
case .STB_TrueType:
|
|
x0, y0, x1, y1 : i32
|
|
success := cast(bool) stbtt.GetGlyphBox( & font.stbtt_info, i32(glyph_index), & x0, & y0, & x1, & y1 )
|
|
assert( success )
|
|
|
|
bounds_0 = { i32(x0), i32(y0) }
|
|
bounds_1 = { i32(x1), i32(y1) }
|
|
}
|
|
return
|
|
}
|
|
|
|
parser_get_glyph_shape :: proc( font : ^ParserFontInfo, glyph_index : Glyph ) -> (shape : ParserGlyphShape, error : AllocatorError)
|
|
{
|
|
switch font.kind
|
|
{
|
|
case .Freetype:
|
|
error := freetype.load_glyph(font.freetype_info, cast(u32)glyph_index, {.No_Bitmap, .No_Hinting, .No_Scale})
|
|
if error != .Ok {
|
|
return
|
|
}
|
|
|
|
glyph := font.freetype_info.glyph
|
|
if glyph.format != .Outline {
|
|
return
|
|
}
|
|
|
|
outline := &glyph.outline
|
|
n_points := int(outline.n_points)
|
|
n_contours := int(outline.n_contours)
|
|
|
|
vertices, alloc_error := make([dynamic]ParserGlyphVertex, 0, n_points + n_contours)
|
|
if alloc_error != .None {
|
|
// Handle allocation error
|
|
return
|
|
}
|
|
|
|
points := slice.from_ptr(cast([^]freetype.Vector) outline.points, n_points)
|
|
tags := slice.from_ptr(cast([^]u8) outline.tags, n_points)
|
|
contours := slice.from_ptr(cast([^]i16) outline.contours, n_contours)
|
|
|
|
start := 0
|
|
for contour_index in 0 ..< n_contours
|
|
{
|
|
end := int(contours[contour_index]) + 1
|
|
|
|
first_point := points[start]
|
|
append( & vertices, ParserGlyphVertex { type = .Move, x = i16(first_point.x), y = i16(first_point.y) })
|
|
|
|
for point_index := start; point_index < end; point_index += 1
|
|
{
|
|
tag := tags[point_index]
|
|
point := points[point_index]
|
|
next_point := points[(point_index + 1) % end]
|
|
|
|
if tag & 1 == 0
|
|
{
|
|
// Off-curve point
|
|
if tags[(point_index + 1) % end] & 1 == 0
|
|
{
|
|
// Next is also off-curve
|
|
mid_point := Vec2{
|
|
(f32(point.x) + f32(next_point.x)) / 2,
|
|
(f32(point.y) + f32(next_point.y)) / 2,
|
|
}
|
|
append(&vertices, ParserGlyphVertex {
|
|
type = .Curve,
|
|
x = i16(mid_point.x),
|
|
y = i16(mid_point.y),
|
|
contour_x0 = i16(point.x),
|
|
contour_y0 = i16(point.y),
|
|
})
|
|
}
|
|
else
|
|
{
|
|
// Next is on-curve
|
|
append(&vertices, ParserGlyphVertex{
|
|
type = .Curve,
|
|
x = i16(next_point.x),
|
|
y = i16(next_point.y),
|
|
contour_x0 = i16(point.x),
|
|
contour_y0 = i16(point.y),
|
|
})
|
|
point_index += 1
|
|
}
|
|
}
|
|
else
|
|
{
|
|
// On-curve point
|
|
append(&vertices, ParserGlyphVertex{
|
|
type = .Line,
|
|
x = i16(point.x), y = i16(point.y),
|
|
})
|
|
}
|
|
}
|
|
|
|
start = end
|
|
}
|
|
|
|
shape = vertices
|
|
|
|
case .STB_TrueType:
|
|
stb_shape : [^]stbtt.vertex
|
|
nverts := stbtt.GetGlyphShape( & font.stbtt_info, cast(i32) glyph_index, & stb_shape )
|
|
|
|
shape_raw := transmute( ^runtime.Raw_Dynamic_Array) & shape
|
|
shape_raw.data = stb_shape
|
|
shape_raw.len = int(nverts)
|
|
shape_raw.cap = int(nverts)
|
|
shape_raw.allocator = runtime.nil_allocator()
|
|
error = AllocatorError.None
|
|
return
|
|
}
|
|
|
|
return
|
|
}
|
|
|
|
parser_is_glyph_empty :: #force_inline proc "contextless" ( font : ^ParserFontInfo, glyph_index : Glyph ) -> b32
|
|
{
|
|
switch font.kind
|
|
{
|
|
case .Freetype:
|
|
error := freetype.load_glyph( font.freetype_info, cast(u32) glyph_index, { .No_Bitmap, .No_Hinting, .No_Scale } )
|
|
if error == .Ok
|
|
{
|
|
if font.freetype_info.glyph.format == .Outline {
|
|
return font.freetype_info.glyph.outline.n_points == 0
|
|
}
|
|
else if font.freetype_info.glyph.format == .Bitmap {
|
|
return font.freetype_info.glyph.bitmap.width == 0 && font.freetype_info.glyph.bitmap.rows == 0;
|
|
}
|
|
}
|
|
return false
|
|
|
|
case .STB_TrueType:
|
|
return stbtt.IsGlyphEmpty( & font.stbtt_info, cast(c.int) glyph_index )
|
|
}
|
|
return false
|
|
}
|
|
|
|
parser_scale :: #force_inline proc "contextless" ( font : ^ParserFontInfo, size : f32 ) -> f32
|
|
{
|
|
size_scale := size < 0.0 ? \
|
|
parser_scale_for_pixel_height( font, -size ) \
|
|
: parser_scale_for_mapping_em_to_pixels( font, size )
|
|
// size_scale = 1.0
|
|
return size_scale
|
|
}
|
|
|
|
parser_scale_for_pixel_height :: #force_inline proc "contextless" ( font : ^ParserFontInfo, size : f32 ) -> f32
|
|
{
|
|
switch font.kind {
|
|
case .Freetype:
|
|
freetype.set_pixel_sizes( font.freetype_info, 0, cast(u32) size )
|
|
size_scale := size / cast(f32)font.freetype_info.units_per_em
|
|
return size_scale
|
|
|
|
case.STB_TrueType:
|
|
return stbtt.ScaleForPixelHeight( & font.stbtt_info, size )
|
|
}
|
|
return 0
|
|
}
|
|
|
|
parser_scale_for_mapping_em_to_pixels :: #force_inline proc "contextless" ( font : ^ParserFontInfo, size : f32 ) -> f32
|
|
{
|
|
switch font.kind {
|
|
case .Freetype:
|
|
Inches_To_CM :: cast(f32) 2.54
|
|
Points_Per_CM :: cast(f32) 28.3465
|
|
CM_Per_Point :: cast(f32) 1.0 / DPT_DPCM
|
|
CM_Per_Pixel :: cast(f32) 1.0 / DPT_PPCM
|
|
DPT_DPCM :: cast(f32) 72.0 * Inches_To_CM // 182.88 points/dots per cm
|
|
DPT_PPCM :: cast(f32) 96.0 * Inches_To_CM // 243.84 pixels per cm
|
|
DPT_DPI :: cast(f32) 72.0
|
|
|
|
// TODO(Ed): Don't assume the dots or pixels per inch.
|
|
system_dpi :: DPT_DPI
|
|
|
|
FT_Font_Size_Point_Unit :: 1.0 / 64.0
|
|
FT_Point_10 :: 64.0
|
|
|
|
points_per_em := (size / system_dpi ) * DPT_DPI
|
|
freetype.set_char_size( font.freetype_info, 0, cast(freetype.F26Dot6) f32(points_per_em * FT_Point_10), cast(u32) DPT_DPI, cast(u32) DPT_DPI )
|
|
size_scale := f32(f64(size) / cast(f64) font.freetype_info.units_per_em)
|
|
return size_scale
|
|
|
|
case .STB_TrueType:
|
|
return stbtt.ScaleForMappingEmToPixels( & font.stbtt_info, size )
|
|
}
|
|
return 0
|
|
}
|
|
|
|
when false {
|
|
parser_convert_conic_to_cubic_freetype :: proc( vertices : Array(ParserGlyphVertex), p0, p1, p2 : freetype.Vector, tolerance : f32 )
|
|
{
|
|
scratch : [Kilobyte * 4]u8
|
|
scratch_arena : Arena; arena_init(& scratch_arena, scratch[:])
|
|
|
|
points, error := make( Array(freetype.Vector), 256, allocator = arena_allocator( &scratch_arena) )
|
|
assert(error == .None)
|
|
|
|
append( & points, p0)
|
|
append( & points, p1)
|
|
append( & points, p2)
|
|
|
|
to_float : f32 = 1.0 / 64.0
|
|
control_conv :: f32(2.0 / 3.0) // Conic to cubic control point distance
|
|
|
|
for ; points.num > 1; {
|
|
p0 := points.data[0]
|
|
p1 := points.data[1]
|
|
p2 := points.data[2]
|
|
|
|
fp0 := Vec2{ f32(p0.x), f32(p0.y) } * to_float
|
|
fp1 := Vec2{ f32(p1.x), f32(p1.y) } * to_float
|
|
fp2 := Vec2{ f32(p2.x), f32(p2.y) } * to_float
|
|
|
|
delta_x := fp0.x - 2 * fp1.x + fp2.x;
|
|
delta_y := fp0.y - 2 * fp1.y + fp2.y;
|
|
distance := math.sqrt(delta_x * delta_x + delta_y * delta_y);
|
|
|
|
if distance <= tolerance
|
|
{
|
|
control1 := {
|
|
|
|
}
|
|
}
|
|
else
|
|
{
|
|
control2 := {
|
|
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|