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add Font::Glyph class

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This commit is contained in:
Josh Holtrop 2014-06-23 14:23:34 -04:00
parent 959a2571af
commit 91e6988fce
2 changed files with 109 additions and 2 deletions
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73
src/gui/Font.cc
View File

@ -1,5 +1,8 @@
#include "Font.h"
#include <iostream>
#include <stdint.h>
#define round_up_26_6(val) (((val) + 63) >> 6u)
namespace jes
{
@ -26,6 +29,76 @@ namespace jes
FT_Set_Pixel_Sizes(m_face, 0, size);
m_line_height = round_up_26_6(m_face->size->metrics.height);
m_loaded = true;
return true;
}
Font::GlyphRef Font::load_glyph(FT_ULong char_code)
{
GlyphRef glyph = new Glyph();
if (glyph->load(m_face, char_code))
return glyph;
return NULL;
}
Font::Glyph::Glyph()
{
m_loaded = false;
}
Font::Glyph::~Glyph()
{
if (m_loaded)
{
glDeleteTextures(1, &m_texture_id);
}
}
bool Font::Glyph::load(FT_Face face, FT_ULong char_code)
{
if (FT_Load_Char(face, char_code, FT_LOAD_RENDER) != 0)
return false;
int width = face->glyph->bitmap.width;
int height = face->glyph->bitmap.rows;
m_left = face->glyph->bitmap_left;
m_top = face->glyph->bitmap_top;
m_advance = round_up_26_6(face->glyph->advance.x);
uint8_t * texture = new uint8_t[width * height];
for (int i = 0; i < height; i++)
{
memcpy(&texture[width * i],
&face->glyph->bitmap.buffer[width * (height - i - 1)],
width);
}
glGenTextures(1, &m_texture_id);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, m_texture_id);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, width, height, 0, GL_ALPHA, GL_UNSIGNED_BYTE, texture);
delete[] texture;
float w = width - 1;
float h = height - 1;
float s = 1.0 / (width * 2);
float t = 1.0 / (height * 2);
GLfloat box[4][4] = {
{0, 0, s, t},
{w, 0, 1 - s, t},
{0, h, s, 1 - t},
{w, h, 1 - s, 1 - t},
};
glGenBuffers(1, &m_vbo_id);
glBindBuffer(GL_ARRAY_BUFFER, m_vbo_id);
glBufferData(GL_ARRAY_BUFFER, sizeof(box), box, GL_STATIC_DRAW);
m_loaded = true;
return true;
}

38
src/gui/Font.h
View File

@ -4,20 +4,54 @@
#include "jes/Ref.h"
#include <ft2build.h>
#include FT_FREETYPE_H
#include "gl3w.h"
#include <unordered_map>
namespace jes
{
class Font
{
public:
class Glyph
{
public:
Glyph();
~Glyph();
bool load(FT_Face face, FT_ULong char_code);
int get_top() { return m_top; }
int get_left() { return m_left; }
int get_advance() { return m_advance; }
void draw()
{
glBindTexture(GL_TEXTURE_2D, m_texture_id);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, 0);
glBindBuffer(GL_ARRAY_BUFFER, m_vbo_id);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
}
protected:
bool m_loaded;
int m_top;
int m_left;
int m_advance;
GLuint m_texture_id;
GLuint m_vbo_id;
};
typedef Ref<Glyph> GlyphRef;
Font();
~Font();
bool load(FT_Library ft, const char * fname, size_t size);
int get_line_height() { return round_up_26_6(m_face->size->metrics.height); }
int get_line_height() { return m_line_height; }
int get_advance() { return m_advance; }
protected:
int round_up_26_6(int val) { return (val + 63) >> 6u; }
GlyphRef load_glyph(FT_ULong char_code);
FT_Face m_face;
int m_line_height;
int m_advance;
bool m_loaded;
std::unordered_map<FT_ULong, GlyphRef> m_glyphs;
};
typedef Ref<Font> FontRef;