jes/src-c/gui/Glyph.cc
2018-07-25 20:47:02 -04:00

53 lines
2.0 KiB
C++

#include "Glyph.h"
#define round_up_26_6(val) (((val) + 63) >> 6u)
bool Glyph::load(FT_Face face, FT_ULong char_code)
{
if (FT_Load_Char(face, char_code, FT_LOAD_RENDER) != 0)
return false;
m_texture = glcxx::Texture::create();
m_texture->bind(GL_TEXTURE_2D);
int width = face->glyph->bitmap.width;
int rounded_width = glcxx::Texture::next_power_of_2(width);
int height = face->glyph->bitmap.rows;
int rounded_height = glcxx::Texture::next_power_of_2(height);
m_advance = round_up_26_6(face->glyph->advance.x);
uint8_t * texture = new uint8_t[rounded_width * rounded_height];
memset(texture, 0, rounded_width * rounded_height);
for (int i = 0; i < height; i++)
{
memcpy(&texture[rounded_width * i],
&face->glyph->bitmap.buffer[width * (height - i - 1)],
width);
}
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, rounded_width, rounded_height, 0, GL_ALPHA, GL_UNSIGNED_BYTE, texture);
delete[] texture;
m_array = glcxx::Array::create();
m_array->bind();
int left = face->glyph->bitmap_left;
int top = face->glyph->bitmap_top;
float s_max = width / (float)rounded_width;
float t_max = height / (float)rounded_height;
m_buffer = glcxx::Buffer::create(GL_ARRAY_BUFFER, GL_STATIC_DRAW, {
(GLfloat)left, (GLfloat)(top - height), 0.0, 0.0,
(GLfloat)(left + width), (GLfloat)(top - height), s_max, 0.0,
(GLfloat)left, (GLfloat)top, 0.0, t_max,
(GLfloat)(left + width), (GLfloat)top, s_max, t_max,
});
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, 0);
return true;
}