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// Copyright (c) 2019 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 freetype
import (
os
gx
gg
stbi
glm
gl
)
#flag windows -I @VROOT/thirdparty/freetype/include
#flag windows -L @VROOT/thirdparty/freetype/win64
#flag darwin -I/usr/local/include/freetype2
#flag darwin -I/opt/local/include/freetype2
#flag -lfreetype
//#flag -I @VROOT/thirdparty/freetype
//#flag @VROOT/thirdparty/freetype/libfreetype.a
#flag darwin -lpng -lbz2 -lz
#flag linux -I/usr/include/freetype2
#flag linux -I.
#include "ft2build.h"
#include FT_FREETYPE_H
const (
DEFAULT_FONT_SIZE = 12
)
struct Character {
texture_id u32
size gg.Vec2
bearing gg.Vec2
advance u32
}
struct Face {
cobj voidptr
}
[typedef]
struct C.FT_Library {
}
struct Context {
shader gl.Shader
// use_ortho bool
width int
height int
vao u32
rect_vao u32
rect_vbo u32
line_vao u32
line_vbo u32
vbo u32
chars []Character
utf_runes []string
utf_chars []Character
face Face
scale int // retina = 2 , normal = 1
}
struct C.Bitmap {
width int
rows int
buffer int
}
struct C.Advance {
x int
}
struct C.Glyph {
bitmap Bitmap
bitmap_left int
bitmap_top int
advance Advance
}
[typedef]
struct C.FT_Face {
glyph *Glyph
}
fn ft_load_char(_face Face, code i64) Character {
//println('ftload_char( code=$code)')
//C.printf('face=%p\n', _face)
face := FT_Face(_face.cobj)
ret := int(C.FT_Load_Char(face, code, C.FT_LOAD_RENDER))
if ret != 0 {
println('freetype: failed to load glyph (utf32 code=$code, ' +
'error code=$ret)')
return Character{}
}
// Generate texture
mut texture := 0
C.glGenTextures(1, &texture)
C.glBindTexture(C.GL_TEXTURE_2D, texture)
fgwidth := face.glyph.bitmap.width
fgrows := face.glyph.bitmap.rows
C.glTexImage2D(C.GL_TEXTURE_2D, 0, C.GL_RED, fgwidth, fgrows,
0, C.GL_RED, C.GL_UNSIGNED_BYTE, face.glyph.bitmap.buffer)
// Set texture options
C.glTexParameteri(C.GL_TEXTURE_2D, C.GL_TEXTURE_WRAP_S, C.GL_CLAMP_TO_EDGE)
C.glTexParameteri(C.GL_TEXTURE_2D, C.GL_TEXTURE_WRAP_T, C.GL_CLAMP_TO_EDGE)
C.glTexParameteri(C.GL_TEXTURE_2D, C.GL_TEXTURE_MIN_FILTER, C.GL_LINEAR)
C.glTexParameteri(C.GL_TEXTURE_2D, C.GL_TEXTURE_MAG_FILTER, C.GL_LINEAR)
fgleft := face.glyph.bitmap_left
fgtop := face.glyph.bitmap_top
// Create the character
return Character {
texture_id: u32(texture)
size: gg.vec2(int(u32(fgwidth)), int(u32(fgrows)))
bearing: gg.vec2(int(u32(fgleft)), int(u32(fgtop)))
advance: (u32(face.glyph.advance.x))
}
}
pub fn new_context(cfg gg.Cfg) *Context {
scale := cfg.scale
// Can only have text in ortho mode
if !cfg.use_ortho {
return &Context{}
}
mut width := cfg.width * scale
mut height := cfg.height * scale
font_size := cfg.font_size * scale
// exit('fs=$font_size')
// if false {
// retina
// width = width * 2// scale// 2
// height = height * 2// scale// 2
// font_size *= scale// 2
// }
/*
gl.viewport(0, 0, width, height)
*/
// gl.enable(GL_CULL_FACE) // TODO NEED CULL?
gl.enable(C.GL_BLEND)
C.glBlendFunc(C.GL_SRC_ALPHA, C.GL_ONE_MINUS_SRC_ALPHA)
shader := gl.new_shader('text')
shader.use()
projection := glm.ortho(0, width, 0, height)// 0 at BOT
shader.set_mat4('projection', projection)
// FREETYPE
ft := FT_Library{}
// All functions return a value different than 0 whenever
// an error occurred
mut ret := C.FT_Init_FreeType(&ft)
if ret != 0 {
panic('freetype: Could not init FreeType Library')
}
// Load font as face
mut font_path := cfg.font_path
if font_path == '' {
font_path = 'RobotoMono-Regular.ttf'
}
if !os.file_exists(font_path) {
exe_path := os.executable()
exe_dir := os.basedir(exe_path)
font_path = '$exe_dir/$font_path'
}
if !os.file_exists(font_path) {
println('failed to load $font_path')
return 0
}
println('Trying to load font from $font_path')
face := C.FT_Face{}
ret = int(C.FT_New_Face(ft, font_path.str, 0, &face))
if ret != 0 {
println('freetype: failed to load the font (error=$ret)')
exit(1)
}
// Set size to load glyphs as
C.FT_Set_Pixel_Sizes(face, 0, font_size)
// Disable byte-alignment restriction
C.glPixelStorei(C.GL_UNPACK_ALIGNMENT, 1)
// Gen texture
// Load first 128 characters of ASCII set
mut chars := []Character{}
f := Face {
cobj: &face
}
for c := 0; c < 128; c++ {
mut ch := ft_load_char(f, i64(c))
// s := utf32_to_str(uint(0x043f))
// s := 'п'
// ch = ft_load_char(f, s.utf32_code())
// # unsigned long c = FT_Get_Char_Index(face, 0x043f );
// # printf("!!!!!!!!! %lu\n", c);
// # c = FT_Get_Char_Index(face, 0xd0bf );
// # printf("!!!!!!!!! %lu\n", c);
// # ch = gg__ft_load_char(f, 0xd0bf) ; // UTF 8
chars << ch
}
ch := Character{}
// Configure VAO
vao := gl.gen_vertex_array()
println('new gg text context vao=$vao')
vbo := gl.gen_buffer()
gl.bind_vao(vao)
gl.bind_buffer(C.GL_ARRAY_BUFFER, vbo)
// # glBufferData(GL_ARRAY_BUFFER, sizeof(GLf32) * 6 * 4, NULL, GL_DYNAMIC_DRAW);
gl.enable_vertex_attrib_array(0)
gl.vertex_attrib_pointer(0, 4, C.GL_FLOAT, false, 4, 0)
// # glVertexAttribPointer(0, 4, GL_FLOAT,false, 4 * sizeof(GLf32), 0);
// gl.bind_buffer(GL_ARRAY_BUFFER, uint(0))
// # glBindVertexArray(0);
mut ctx := &Context {
shader: shader
width: width
height: height
scale: scale
vao: vao
vbo: vbo
chars: chars
face: f
}
ctx.init_utf8_runes()
return ctx
}
// A dirty hack to implement rendering of cyrillic letters.
// All UTF-8 must be supported.
fn (ctx mut Context) init_utf8_runes() {
s := 'йцукенгшщзхъфывапролджэячсмитьбюЙЦУКЕНГШЩЗХЪФЫВАПРОЛДЖЭЯЧСМИТЬБЮ'
print('init utf8 runes: ')
//println(s)
us := s.ustring()
for i := 0; i < us.len; i++ {
_rune := us.at(i)
ch := ft_load_char(ctx.face, _rune.utf32_code())
// ctx.utf_rune_map.set(rune, ch)
ctx.utf_runes << _rune
ctx.utf_chars << ch
}
}
pub fn (ctx mut Context) draw_text(_x, _y int, text string, cfg gx.TextCfg) {
//utext := text.ustring_tmp()
utext := text.ustring()
ctx._draw_text(_x, _y, utext, cfg)
}
fn (ctx mut Context) draw_text_fast(_x, _y int, text ustring, cfg gx.TextCfg) {
ctx._draw_text(_x, _y, text, cfg)
}
fn (ctx mut Context) _draw_text(_x, _y int, utext ustring, cfg gx.TextCfg) {
/*
if utext.s.contains('on_seg') {
println('\nat(0)')
println(utext.runes)
firstc := utext.at(0)
println('drawtext "$utext.s" len=$utext.s.len ulen=$utext.len x=$_x firstc=$firstc')
if firstc != ' ' {
exit(1)
}
}
*/
mut x := f32(_x)
mut y := f32(_y)
// println('scale=$ctx.scale size=$cfg.size')
if cfg.align == gx.ALIGN_RIGHT {
width := utext.len * 7
x -= width + 10
}
x *= ctx.scale// f32(2)
// println('y=$_y height=$ctx.height')
// _y = _y * int(ctx.scale) //+ 26
y = y * int(ctx.scale) + ((cfg.size * ctx.scale) / 2) + 5 * ctx.scale
y = f32(ctx.height) - y
color := cfg.color
// Activate corresponding render state
ctx.shader.use()
ctx.shader.set_color('textColor', color)
C.glActiveTexture(C.GL_TEXTURE0)
gl.bind_vao(ctx.vao)
// Iterate through all characters
// utext := text.ustring()
for i := 0; i < utext.len; i++ {
_rune := utext.at(i)
// println('$i => $_rune')
mut ch := Character{}
if _rune.len == 1 {
idx := _rune[0]
if idx < 0 || idx >= ctx.chars.len {
println('BADE RUNE $_rune')
continue
}
ch = ctx.chars[_rune[0]]
}
else if _rune.len > 1 {
// TODO O(1) use map
for j := 0; j < ctx.utf_runes.len; j++ {
rune_j := ctx.utf_runes[j]
if rune_j==_rune {
ch = ctx.utf_chars[j]
break
}
}
}
if ch.size.x == 0 && _rune.len > 1{
c := _rune[0]
println('cant draw rune "$_rune" code=$c, loading')
continue
ch = ft_load_char(ctx.face, _rune.utf32_code())
println('done loading')
ctx.utf_runes << _rune
ctx.utf_chars << ch
// continue
}
xpos := x + f32(ch.bearing.x) * 1
ypos := y - f32(ch.size.y - ch.bearing.y) * 1
w := f32(ch.size.x) * 1
h := f32(ch.size.y) * 1
// Update VBO for each character
vertices := [
xpos, ypos + h, 0.0, 0.0 ,
xpos, ypos, 0.0, 1.0 ,
xpos + w, ypos, 1.0, 1.0 ,
xpos, ypos + h, 0.0, 0.0 ,
xpos + w, ypos, 1.0, 1.0 ,
xpos + w, ypos + h, 1.0, 0.0
]
// Render glyph texture over quad
C.glBindTexture(C.GL_TEXTURE_2D, ch.texture_id)
// Update content of VBO memory
gl.bind_buffer(C.GL_ARRAY_BUFFER, ctx.vbo)
// glBufferSubData(..)
C.glBufferData(C.GL_ARRAY_BUFFER, 96, vertices.data, C.GL_DYNAMIC_DRAW)
// Render quad
gl.draw_arrays(C.GL_TRIANGLES, 0, 6)
// Now advance cursors for next glyph (note that advance is number of 1/64 pixels)
// Bitshift by 6 to get value in pixels (2^6 = 64 (divide amount of 1/64th pixels by 64 to get amount of pixels))
x += ch.advance >> u32(6)
}
gl.bind_vao(u32(0))
C.glBindTexture(C.GL_TEXTURE_2D, 0)
}
pub fn (ctx mut Context) draw_text_def(x, y int, text string) {
cfg := gx.TextCfg {
color: gx.Black,
size: DEFAULT_FONT_SIZE,
align: gx.ALIGN_LEFT,
}
ctx.draw_text(x, y, text, cfg)
}