Files
Cubed/src/tools/font.cpp
2026-04-16 10:44:05 +08:00

124 lines
3.8 KiB
C++

#include <Cubed/shader.hpp>
#include <Cubed/tools/font.hpp>
#include <Cubed/tools/log.hpp>
#include <Cubed/tools/shader_tools.hpp>
Font::Font() {
if (FT_Init_FreeType(&m_ft)) {
Logger::error("FREETYPE: Could not init FreeType Library");
}
if (FT_New_Face(m_ft, "assets/fonts/IBMPlexSans-Regular.ttf", 0, &m_face)) {
Logger::error("FREETYPE: Failed to load font");
}
FT_Set_Pixel_Sizes(m_face, 0, 48);
setup_font_character();
}
Font::~Font() {
FT_Done_Face(m_face);
FT_Done_FreeType(m_ft);
glDeleteTextures(1, &m_text_texture);
}
void Font::load_character(char8_t c) {
if (FT_Load_Char(m_face, c, FT_LOAD_RENDER)) {
Logger::error("FREETYTPE: Failed to load Glyph");
return;
}
const auto& width = m_face->glyph->bitmap.width;
const auto& height = m_face->glyph->bitmap.rows;
glBindTexture(GL_TEXTURE_2D_ARRAY, m_text_texture);
glTexSubImage3D(
GL_TEXTURE_2D_ARRAY,
0,
0,
0,
static_cast<int>(c),
width,
height,
1,
GL_RED,
GL_UNSIGNED_BYTE,
m_face->glyph->bitmap.buffer
);
Character character = {
glm::vec2{0.0f, 0.0f},
glm::vec2{static_cast<float>(width) / m_texture_width, static_cast<float>(height) / m_texture_height},
glm::ivec2(m_face->glyph->bitmap.width, m_face->glyph->bitmap.rows),
glm::ivec2(m_face->glyph->bitmap_left, m_face->glyph->bitmap_top),
static_cast<GLuint>(m_face->glyph->advance.x)
};
m_characters.insert({c, std::move(character)});
}
void Font::setup_font_character() {
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glGenTextures(1, &m_text_texture);
glBindTexture(GL_TEXTURE_2D_ARRAY, m_text_texture);
glTexImage3D(
GL_TEXTURE_2D_ARRAY,
0,
GL_RED,
m_texture_width,
m_texture_height,
MAX_CHARACTER,
0,
GL_RED,
GL_UNSIGNED_BYTE,
nullptr
);
for (char8_t c = 0; c < 128; c++) {
load_character(c);
}
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glBindTexture(GL_TEXTURE_2D_ARRAY, 0);
}
std::vector<Vertex2D> Font::vertices(const std::string &text, float x, float y, float scale) {
static Font font;
std::vector<Vertex2D> vertices;
for (char8_t c : text) {
auto it = font.m_characters.find(c);
if (it == font.m_characters.end()) {
Logger::error("Can't find character {}", static_cast<char>(c));
continue;
}
Character& ch = it->second;
float xpos = x + ch.bearing.x * scale;
float ypos = y - ch.bearing.y * scale;
float w = ch.size.x * scale;
float h = ch.size.y * scale;
vertices.emplace_back(xpos, ypos + h, ch.uv_min.x, ch.uv_max.y, static_cast<float>(c));
vertices.emplace_back(xpos, ypos, ch.uv_min.x, ch.uv_min.y, static_cast<float>(c));
vertices.emplace_back(xpos + w, ypos, ch.uv_max.x, ch.uv_min.y, static_cast<float>(c));
vertices.emplace_back(xpos, ypos + h, ch.uv_min.x, ch.uv_max.y, static_cast<float>(c));
vertices.emplace_back(xpos + w, ypos, ch.uv_max.x, ch.uv_min.y, static_cast<float>(c));
vertices.emplace_back(xpos + w, ypos + h, ch.uv_max.x, ch.uv_max.y, static_cast<float>(c));
x += (ch.advance >> 6) * scale;
}
return vertices;
}
GLuint Font::text_texture() {
return m_text_texture;
}