114 lines
3.3 KiB
C++
114 lines
3.3 KiB
C++
#include "Font.h"
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#include <iostream>
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#include <stdint.h>
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#define round_up_26_6(val) (((val) + 63) >> 6u)
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namespace jes
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{
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Font::Font()
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{
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m_loaded = false;
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}
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Font::~Font()
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{
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if (m_loaded)
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{
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FT_Done_Face(m_face);
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}
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}
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bool Font::load(FT_Library ft, const char * fname, size_t size)
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{
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if (FT_New_Face(ft, fname, 0, &m_face) != 0)
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{
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std::cerr << "Could not load font " << fname << std::endl;
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return false;
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}
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FT_Set_Pixel_Sizes(m_face, 0, size);
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GlyphRef x_glyph = load_glyph('x');
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if (x_glyph == NULL)
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{
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std::cerr << "Could not load 'x' glyph from font" << fname << std::endl;
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return false;
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}
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m_glyphs['x'] = x_glyph;
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m_advance = x_glyph->get_advance();
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m_line_height = round_up_26_6(m_face->size->metrics.height);
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m_baseline_offset = round_up_26_6((m_face->size->metrics.height - (m_face->size->metrics.ascender - m_face->size->metrics.descender)) / 2 - m_face->size->metrics.descender);
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m_loaded = true;
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return true;
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}
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Font::GlyphRef Font::load_glyph(FT_ULong char_code)
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{
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GlyphRef glyph = new Glyph();
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if (glyph->load(m_face, char_code))
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return glyph;
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return NULL;
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}
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Font::Glyph::Glyph()
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{
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m_loaded = false;
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}
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Font::Glyph::~Glyph()
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{
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if (m_loaded)
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{
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glDeleteTextures(1, &m_texture_id);
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}
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}
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bool Font::Glyph::load(FT_Face face, FT_ULong char_code)
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{
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if (FT_Load_Char(face, char_code, FT_LOAD_RENDER) != 0)
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return false;
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int width = face->glyph->bitmap.width;
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int height = face->glyph->bitmap.rows;
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int left = face->glyph->bitmap_left;
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int top = face->glyph->bitmap_top;
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m_advance = round_up_26_6(face->glyph->advance.x);
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uint8_t * texture = new uint8_t[width * height];
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for (int i = 0; i < height; i++)
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{
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memcpy(&texture[width * i],
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&face->glyph->bitmap.buffer[width * (height - i - 1)],
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width);
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}
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glGenTextures(1, &m_texture_id);
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glActiveTexture(GL_TEXTURE0);
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glBindTexture(GL_TEXTURE_2D, m_texture_id);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
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glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
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glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, width, height, 0, GL_ALPHA, GL_UNSIGNED_BYTE, texture);
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delete[] texture;
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float s = 1.0 / (width * 2);
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float t = 1.0 / (height * 2);
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GLfloat box[4][4] = {
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{(GLfloat)left, (GLfloat)(top - height), s, t},
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{(GLfloat)(left + width - 1), (GLfloat)(top - height), 1 - s, t},
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{(GLfloat)left, (GLfloat)(top - 1), s, 1 - t},
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{(GLfloat)(left + width - 1), (GLfloat)(top - 1), 1 - s, 1 - t},
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};
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glGenBuffers(1, &m_vbo_id);
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glBindBuffer(GL_ARRAY_BUFFER, m_vbo_id);
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glBufferData(GL_ARRAY_BUFFER, sizeof(box), box, GL_STATIC_DRAW);
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m_loaded = true;
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return true;
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}
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}
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