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