feat: add font class and render font function

src/tools/font.cpp

@@ -0,0 +1,112 @@
+
+
+#include <Cubed/tools/font.hpp>
+#include <Cubed/tools/log.hpp>
+
+
+
+
+Font::Font() {
+
+    if (FT_Init_FreeType(&m_ft)) {
+        LOG::error("FREETYPE: Could not init FreeType Library");
+    }
+    if (FT_New_Face(m_ft, "assets/fonts/IBMPlexSans-Regular.ttf", 0, &m_face)) {
+        LOG::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);
+    for (const auto& [key, character] : m_characters) {
+        glDeleteTextures(1, &character.texture_id);
+    }
+}
+
+void Font::load_character(char8_t c) {
+    if (FT_Load_Char(m_face, c, FT_LOAD_RENDER)) {
+            LOG::error("FREETYTPE: Failed to load Glyph");
+            return;
+        }
+        GLuint texture;
+        glGenTextures(1, &texture);
+        glBindTexture(GL_TEXTURE_2D, texture);
+        glTexImage2D(
+            GL_TEXTURE_2D,
+            0,
+            GL_RED,
+            m_face->glyph->bitmap.width,
+            m_face->glyph->bitmap.rows,
+            0,
+            GL_RED,
+            GL_UNSIGNED_BYTE,
+            m_face->glyph->bitmap.buffer
+        );
+        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);
+
+        Character character = {
+            texture,
+            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);  
+    for (char8_t c = 0; c < 128; c++) {
+        load_character(c);
+    }
+}
+
+
+
+void Font::render_text(GLuint program, GLuint vbo, const std::string& text, float x, float y, float scale, const glm::vec3& color) {
+    static Font font;
+    glUseProgram(program);
+    glUniform3f(glGetUniformLocation(program, "textColor"), color.x, color.y, color.z);
+    glActiveTexture(GL_TEXTURE0);
+    for (char8_t c : text) {
+        auto it = font.m_characters.find(c);
+        if (it == font.m_characters.end()) {
+            LOG::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;
+
+        float vertices[6][4] {
+        { xpos,     ypos + h,   0.0, 1.0 },  
+        { xpos,     ypos,       0.0, 0.0 },  
+        { xpos + w, ypos,       1.0, 0.0 },  
+
+        { xpos,     ypos + h,   0.0, 1.0 },  
+        { xpos + w, ypos,       1.0, 0.0 },  
+        { xpos + w, ypos + h,   1.0, 1.0 }  
+        };
+        glBindTexture(GL_TEXTURE_2D, ch.texture_id);
+        glBindBuffer(GL_ARRAY_BUFFER, vbo);
+        glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertices), vertices);
+        glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 4 * sizeof(GLfloat), 0);
+        glEnableVertexAttribArray(0);
+        glDrawArrays(GL_TRIANGLES, 0, 6);
+        x += (ch.advance >> 6) * scale;
+        glBindBuffer(GL_ARRAY_BUFFER, 0);
+    }
+    glBindTexture(GL_TEXTURE_2D, 0);
+
+}