add progress bar to lightmap rendering

src/font.cpp

@@ -17,6 +17,7 @@ bool Font::load(const char* ttf, int font_size)
         auto bitmap = std::make_unique<uint8_t[]>(w*h);
         chars.resize(num_chars);
         stbtt_BakeFontBitmap(file.m_data, 0, (float)font_size*2, bitmap.get(), w, h, start_char, num_chars, chars.data());
+        calc_bounds();
         font_tex.create(w, h, GL_R8, GL_RED, bitmap.get());
         file.close();
         size = font_size;
@@ -25,6 +26,21 @@ bool Font::load(const char* ttf, int font_size)
     return false;
 }
 
+void Font::calc_bounds()
+{
+    glm::vec2 bbmin(FLT_MAX);
+    glm::vec2 bbmax(-FLT_MAX);
+    for (int i = 0; i < num_chars; i++)
+    {
+        stbtt_aligned_quad q;
+        float x = 0, y = 0;
+        stbtt_GetBakedQuad(chars.data(), w, h, i, &x, &y, &q, true);
+        bbmin = glm::min(bbmin, { q.x0 / 2.f, q.y0 / 2.f });
+        bbmax = glm::max(bbmax, { q.x1 / 2.f, q.y1 / 2.f });
+    }
+    bounds = { glm::vec4(bbmin, bbmax) };
+}
+
 void FontManager::init()
 {
     m_sampler.create();