Try to calculate required font atlas bitmap size

Currently results in HUGE textures

app/src/main/cpp/AssetManager.cpp

@@ -37,25 +37,9 @@ bool AssetManager::loadFontData(const char* path, float char_height, FontData* p
     FileBuffer ttf_data = {};
     if (!loadFile(path, &ttf_data))
         return false;
-    static unsigned char bitmap_memory[STBTT_PH_VALUE * STBTT_PH_VALUE];
+
     FontData font_data = {};
     auto* data = reinterpret_cast<const unsigned char*>(ttf_data.data);
-    /*stbtt_BakeFontBitmap(data,
-        0,
-        char_height,
-        bitmap_memory,
-        STBTT_PH_VALUE,
-        STBTT_PH_VALUE,
-        32,
-        225, // latin-1 printable characters range
-        font_data.char_data);*/
-
-    stbtt_pack_context context;
-    stbtt_PackBegin(&context, bitmap_memory, STBTT_PH_VALUE, STBTT_PH_VALUE, 0, 1, nullptr);
-    stbtt_PackSetOversampling(&context, 1, 1);
-    stbtt_PackFontRange(&context, data, 0, STBTT_POINT_SIZE(char_height), 32, 225, font_data.char_data);
-    stbtt_PackFontRange(&context, data, 0, STBTT_POINT_SIZE(char_height), 8364, 1, font_data.char_data + 225);
-    stbtt_PackEnd(&context);
 
     font_data.char_height = char_height;
     int off = stbtt_GetFontOffsetForIndex(data, 0);
@@ -63,6 +47,7 @@ bool AssetManager::loadFontData(const char* path, float char_height, FontData* p
         releaseFileBuffer(ttf_data);
         return false;
     }
+
     stbtt_fontinfo info;
     if (!stbtt_InitFont(&info, data, off)) {
         releaseFileBuffer(ttf_data);
@@ -73,6 +58,37 @@ bool AssetManager::loadFontData(const char* path, float char_height, FontData* p
     int x0, y0, x1, y1;
     stbtt_GetFontBoundingBox(&info, &x0, &y0, &x1, &y1);
     font_data.baseline_adjust = font_data.scale_factor * static_cast<float>(-y0);
+
+    const int GLYPH_COUNT = (225 - 32) + 1;
+
+    float w = font_data.scale_factor * (x1 - x0);
+    float h = font_data.scale_factor * (y1 - y0);
+    size_t size = (int)ceilf((w > h) ? w : h);
+    size *= GLYPH_COUNT;
+    font_data.bitmap_size = size;
+
+    unsigned char* bitmap_memory = (unsigned char*)malloc(font_data.bitmap_size * font_data.bitmap_size);
+
+    stbtt_pack_context context;
+    stbtt_PackBegin(&context, bitmap_memory, font_data.bitmap_size, font_data.bitmap_size, 0, 1, nullptr);
+    stbtt_PackSetOversampling(&context, 1, 1);
+    stbtt_PackFontRange(&context,
+                        reinterpret_cast<const unsigned char*>(ttf_data.data),
+                        0,
+                        STBTT_POINT_SIZE(char_height),
+                        32,
+                        225,
+                        font_data.char_data);
+    stbtt_PackFontRange(&context,
+                        reinterpret_cast<const unsigned char*>(ttf_data.data),
+                        0,
+                        STBTT_POINT_SIZE(char_height),
+                        8364,
+                        1,
+                        font_data.char_data + 225);
+    stbtt_PackEnd(&context);
+    free(bitmap_memory);
+
     *p_font = font_data;
     releaseFileBuffer(ttf_data);
     m_font_cache[lookup_pair] = font_data;
@@ -81,29 +97,30 @@ bool AssetManager::loadFontData(const char* path, float char_height, FontData* p
 bool AssetManager::loadFontBitmap(const char* path, float char_height, Texture* p_texture)
 {
     ZoneScoped;
+
+    FontData font_data;
+    if (!loadFontData(path, char_height, &font_data))
+        return false;
+
     FileBuffer ttf_data = {};
     if (!loadFile(path, &ttf_data))
         return false;
-    static unsigned char bitmap_memory[STBTT_PH_VALUE * STBTT_PH_VALUE];
+
+    unsigned char* bitmap_memory = (unsigned char *)malloc(font_data.bitmap_size * font_data.bitmap_size);
     stbtt_packedchar char_data[226];
-    /*stbtt_BakeFontBitmap(reinterpret_cast<const unsigned char*>(ttf_data.data),
+  
-        0,
-        char_height,
-        bitmap_memory,
-        STBTT_PH_VALUE,
-        STBTT_PH_VALUE,
-        32,
-        225, // latin-1 printable characters range
-        char_data);*/
     stbtt_pack_context context;
-    stbtt_PackBegin(&context, bitmap_memory, STBTT_PH_VALUE, STBTT_PH_VALUE, 0, 1, nullptr);
+    stbtt_PackBegin(&context, bitmap_memory, font_data.bitmap_size, font_data.bitmap_size, 0, 1, nullptr);
     stbtt_PackSetOversampling(&context, 1, 1);
     stbtt_PackFontRange(&context, reinterpret_cast<const unsigned char*>(ttf_data.data),
         0, STBTT_POINT_SIZE(char_height), 32, 225, char_data);
     stbtt_PackFontRange(&context, reinterpret_cast<const unsigned char*>(ttf_data.data),
         0, STBTT_POINT_SIZE(char_height), 8364, 1, char_data + 225);
     stbtt_PackEnd(&context);
-    *p_texture = Texture(STBTT_PH_VALUE, STBTT_PH_VALUE, bitmap_memory, GL_R8);
+    *p_texture = Texture(font_data.bitmap_size, font_data.bitmap_size, bitmap_memory, GL_R8);
     releaseFileBuffer(ttf_data);
+
+    free(bitmap_memory);
+
     return true;
 }

app/src/main/cpp/AssetManager.h

@@ -8,6 +8,8 @@
 #include "Renderer.h"
 #include "Font.h"
 
+#include <map>
+
 // Predefine, because that saves us from including android headers here
 struct AAssetManager;
 
@@ -61,8 +63,10 @@ protected:
     virtual ~AssetManager() = default;
     AssetManager(const AssetManager&) = delete;
     AssetManager& operator=(const AssetManager&) = delete;
+
+private:
+    // FIXME(Kevin): Temporary workaround
+    std::map<std::pair<StringHandle, float>, FontData> m_font_cache;
 };
 
-const int STBTT_PH_VALUE = 1024;
-
 #endif

app/src/main/cpp/Font.h

@@ -20,6 +20,7 @@ struct FontData
     int descent;
     int line_gap;
     float baseline_adjust;
+    size_t bitmap_size;
 };
 
 #endif

app/src/main/cpp/win32_kde.cpp

@@ -97,7 +97,7 @@ int main()
     StringHandle smiley = StringRepository::global->internString("smiley_PNG42.png");
     StringHandle ttf = StringRepository::global->internString("Milky Honey.ttf");
     FontData fd;
-    AssetManager::ptr->loadFontData("Milky Honey.ttf", 24.f, &fd);
+    AssetManager::ptr->loadFontData("Milky Honey.ttf", 128.f, &fd);
     // ENDE BEISPIELCODE
 
     glfwSwapInterval(1);
@@ -192,12 +192,13 @@ int main()
         while (*text) {
             if (*text >= 32 && *text < 128) {
                 stbtt_aligned_quad q;
-                stbtt_GetBakedQuad(fd.char_data, 1024, 1024, *text - 32, &tx, &ty, &q, 1);
+                stbtt_GetPackedQuad(fd.char_data, fd.bitmap_size, fd.bitmap_size, *text - 32, &tx, &ty, &q, 1);
                 float w = q.x1 - q.x0, h = q.y1 - q.y0;
                 Renderer::ptr->addFontRect(q.x0,
                                            q.y0,
                                            w,
                                            h,
+                                           1.f, 0.f, 0.f, 1.f, 
                                            fd.char_height,
                                            ttf,
                                            StringRepository::global->internString("1"),