v/vlib/gg/text_rendering.c.v

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// Copyright (c) 2019-2024 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license that can be found in the LICENSE file.
module gg
import fontstash
import sokol.sfons
import sokol.sgl
import gx
import os
import os.font
struct FT {
pub:
fons &fontstash.Context = unsafe { nil }
font_normal int
font_bold int
font_mono int
font_italic int
pub mut:
fonts_map map[string]int // for storing custom fonts, provided via cfg.family in draw_text()
scale f32 = 1.0
}
const buff_size = int($d('gg_text_buff_size', 2048))
fn clear_atlas_callback(uptr voidptr, error int, _val int) {
if error == 1 { // atlas overflow error code
fons := unsafe { &fontstash.Context(uptr) }
fons.reset_atlas(buff_size, buff_size)
}
}
fn new_ft(c FTConfig) ?&FT {
if c.font_path == '' {
if c.bytes_normal.len > 0 {
fons := sfons.create(buff_size, buff_size, 1)
bytes_normal := c.bytes_normal
bytes_bold := if c.bytes_bold.len > 0 {
c.bytes_bold
} else {
debug_font_println('setting bold variant to normal')
bytes_normal
}
bytes_mono := if c.bytes_mono.len > 0 {
c.bytes_mono
} else {
debug_font_println('setting mono variant to normal')
bytes_normal
}
bytes_italic := if c.bytes_italic.len > 0 {
c.bytes_italic
} else {
debug_font_println('setting italic variant to normal')
bytes_normal
}
fons.set_error_callback(clear_atlas_callback, fons)
return &FT{
fons: fons
font_normal: fons.add_font_mem('sans', bytes_normal.clone(), true)
font_bold: fons.add_font_mem('sans', bytes_bold.clone(), true)
font_mono: fons.add_font_mem('sans', bytes_mono.clone(), true)
font_italic: fons.add_font_mem('sans', bytes_italic.clone(), true)
scale: c.scale
}
} else {
// Load default font
}
}
if c.font_path == '' || !os.exists(c.font_path) {
$if !android {
println('failed to load font "${c.font_path}"')
return none
}
}
mut normal_path := c.font_path
mut bytes := []u8{}
$if android {
// First try any filesystem paths
bytes = os.read_bytes(c.font_path) or { []u8{} }
if bytes.len == 0 {
// ... then try the APK asset path
bytes = os.read_apk_asset(c.font_path) or {
println('failed to load font "${c.font_path}"')
return none
}
}
} $else {
bytes = os.read_bytes(c.font_path) or {
println('failed to load font "${c.font_path}"')
return none
}
}
mut bold_path := if c.custom_bold_font_path != '' {
c.custom_bold_font_path
} else {
font.get_path_variant(c.font_path, .bold)
}
bytes_bold := os.read_bytes(bold_path) or {
debug_font_println('failed to load font "${bold_path}"')
bold_path = c.font_path
bytes
}
mut mono_path := font.get_path_variant(c.font_path, .mono)
bytes_mono := os.read_bytes(mono_path) or {
debug_font_println('failed to load font "${mono_path}"')
mono_path = c.font_path
bytes
}
mut italic_path := font.get_path_variant(c.font_path, .italic)
bytes_italic := os.read_bytes(italic_path) or {
debug_font_println('failed to load font "${italic_path}"')
italic_path = c.font_path
bytes
}
fons := sfons.create(buff_size, buff_size, 1)
debug_font_println('Font used for font_normal : ${normal_path}')
debug_font_println('Font used for font_bold : ${bold_path}')
debug_font_println('Font used for font_mono : ${mono_path}')
debug_font_println('Font used for font_italic : ${italic_path}')
fons.set_error_callback(clear_atlas_callback, fons)
return &FT{
fons: fons
font_normal: fons.add_font_mem('sans', bytes.clone(), true)
font_bold: fons.add_font_mem('sans', bytes_bold.clone(), true)
font_mono: fons.add_font_mem('sans', bytes_mono.clone(), true)
font_italic: fons.add_font_mem('sans', bytes_italic.clone(), true)
scale: c.scale
}
}
// set_text_cfg sets the current text configuration
pub fn (ctx &Context) set_text_cfg(cfg gx.TextCfg) {
if !ctx.font_inited {
return
}
if cfg.family != '' {
// println('set text cfg family=${cfg.family}')
mut f := ctx.ft.fonts_map[cfg.family]
if f == 0 {
// No such font in the cache yet, create it
bytes := os.read_bytes(cfg.family) or {
debug_font_println('failed to load font "${cfg.family}"')
return
}
f = ctx.ft.fons.add_font_mem(cfg.family, bytes.clone(), true)
unsafe {
ctx.ft.fonts_map[cfg.family] = f
}
}
ctx.ft.fons.set_font(f)
} else if cfg.bold {
ctx.ft.fons.set_font(ctx.ft.font_bold)
} else if cfg.mono {
ctx.ft.fons.set_font(ctx.ft.font_mono)
} else if cfg.italic {
ctx.ft.fons.set_font(ctx.ft.font_italic)
} else {
ctx.ft.fons.set_font(ctx.ft.font_normal)
}
scale := if ctx.ft.scale == 0 { f32(1) } else { ctx.ft.scale }
size := if cfg.mono { cfg.size - 2 } else { cfg.size }
ctx.ft.fons.set_size(scale * f32(size))
ctx.ft.fons.set_align(int(cfg.align) | int(cfg.vertical_align))
color := sfons.rgba(cfg.color.r, cfg.color.g, cfg.color.b, cfg.color.a)
if cfg.color.a != 255 {
sgl.load_pipeline(ctx.pipeline.alpha)
}
ctx.ft.fons.set_color(color)
ascender := f32(0.0)
descender := f32(0.0)
lh := f32(0.0)
ctx.ft.fons.vert_metrics(&ascender, &descender, &lh)
}
@[params]
pub struct DrawTextParams {
pub:
x int
y int
text string
color Color = gx.black
size int = 16
align gx.HorizontalAlign = .left
vertical_align gx.VerticalAlign = .top
max_width int
family string
bold bool
mono bool
italic bool
}
pub fn (ctx &Context) draw_text2(p DrawTextParams) {
ctx.draw_text(p.x, p.y, p.text, gx.TextCfg{
color: p.color
size: p.size
align: p.align
vertical_align: p.vertical_align
max_width: p.max_width
family: p.family
bold: p.bold
mono: p.mono
italic: p.italic
}) // TODO: perf once it's the only function to draw text
}
// draw_text draws the string in `text_` starting at top-left position `x`,`y`.
// Text settings can be provided with `cfg`.
pub fn (ctx &Context) draw_text(x int, y int, text_ string, cfg gx.TextCfg) {
$if macos {
if ctx.native_rendering {
if cfg.align == gx.align_right {
width := ctx.text_width(text_)
// println('draw text ctx.height = ${ctx.height}')
C.darwin_draw_string(x - width, ctx.height - y, text_, cfg)
} else {
C.darwin_draw_string(x, ctx.height - y, text_, cfg)
}
return
}
}
if !ctx.font_inited {
eprintln('gg: draw_text(): font not initialized')
return
}
// text := text_.trim_space() // TODO: remove/optimize
// mut text := text_
// if text.contains('\t') {
// text = text.replace('\t', ' ')
// }
ctx.set_text_cfg(cfg)
scale := if ctx.ft.scale == 0 { f32(1) } else { ctx.ft.scale }
ctx.ft.fons.draw_text(x * scale, y * scale, text_) // TODO: check offsets/alignment
}
// draw_text draws the string in `text_` starting at top-left position `x`,`y` using
// default text settings.
pub fn (ctx &Context) draw_text_def(x int, y int, text string) {
ctx.draw_text(x, y, text)
}
// flush prepares the font for use.
pub fn (ft &FT) flush() {
sfons.flush(ft.fons)
}
// text_width returns the width of the `string` `s` in pixels.
pub fn (ctx &Context) text_width(s string) int {
$if macos {
if ctx.native_rendering {
return C.darwin_text_width(s)
}
}
// ctx.set_text_cfg(cfg) TODO
if !ctx.font_inited {
return 0
}
mut buf := [4]f32{}
ctx.ft.fons.text_bounds(0, 0, s, &buf[0])
if s.ends_with(' ') {
return int((buf[2] - buf[0]) / ctx.scale) +
ctx.text_width('i') // TODO: fix this in fontstash?
}
res := int((buf[2] - buf[0]) / ctx.scale)
// println('TW "$s" = $res')
$if macos {
if ctx.native_rendering {
return res * 2
}
}
return int((buf[2] - buf[0]) / ctx.scale)
}
// text_height returns the height of the `string` `s` in pixels.
pub fn (ctx &Context) text_height(s string) int {
// ctx.set_text_cfg(cfg) TODO
if !ctx.font_inited {
return 0
}
mut buf := [4]f32{}
ctx.ft.fons.text_bounds(0, 0, s, &buf[0])
return int((buf[3] - buf[1]) / ctx.scale)
}
// text_size returns the width and height of the `string` `s` in pixels.
pub fn (ctx &Context) text_size(s string) (int, int) {
// ctx.set_text_cfg(cfg) TODO
if !ctx.font_inited {
return 0, 0
}
mut buf := [4]f32{}
ctx.ft.fons.text_bounds(0, 0, s, &buf[0])
return int((buf[2] - buf[0]) / ctx.scale), int((buf[3] - buf[1]) / ctx.scale)
}