fixt Improve text rendering

3 files changed, 39 insertions, 23 deletions

diff --git a/src/vk/character.cpp b/src/vk/character.cpp
index 04ddb0c..e5eb87f 100644
--- a/src/vk/character.cpp
+++ b/src/vk/character.cpp
@@ -61,19 +61,28 @@ load_image(void *obj)
   error = FT_Render_Glyph(self->face->glyph, FT_RENDER_MODE_NORMAL);
   if(error) throw CommandError{"failed to render glyph"};
 
+  self->character->bearing_x = self->face->glyph->bitmap_left;
+  self->character->bearing_y = self->face->glyph->bitmap_top;
+  self->character->advance = (self->face->glyph->advance.x >> 6);
   self->character->width = self->face->glyph->bitmap.width;
   self->character->height = self->face->glyph->bitmap.rows;
   self->character->mip_levels = 1;
-  self->character->bearing_x = self->face->glyph->bitmap_left;
-  self->character->bearing_y = self->face->glyph->bitmap_top;
-  self->character->advance = self->face->glyph->bitmap.width; // self->face->glyph->advance.x;
+
+  // Character is a white-space.
+  if(self->character->width <= 0)
+  {
+    self->character->image = VK_NULL_HANDLE;
+    self->character->device_memory = VK_NULL_HANDLE;
+
+    return;
+  }
 
   auto image_size{static_cast<size_t>(
       self->face->glyph->bitmap.width *
       self->face->glyph->bitmap.rows * num_channels)};
 
   { // Create the data for the image buffer
-    source_image_raw.resize(image_size);
+    source_image_raw.resize(image_size, 0);
 
     for(auto y{0}; y < self->face->glyph->bitmap.width; y++)
     {
@@ -83,11 +92,11 @@ load_image(void *obj)
           x * num_channels;
         auto glyph_coord = y * self->face->glyph->bitmap.rows + x;
         // Red
-        source_image_raw[image_coord] = 0;
+        source_image_raw[image_coord] = 255;
         // Green
-        source_image_raw[image_coord + 1] = 0;
+        source_image_raw[image_coord + 1] = 255;
         // Blue
-        source_image_raw[image_coord + 2] = 0;
+        source_image_raw[image_coord + 2] = 255;
         // Alpha
         source_image_raw[image_coord + 3] =
           self->face->glyph->bitmap.buffer[glyph_coord];
diff --git a/src/vk/character.hpp b/src/vk/character.hpp
index c1dfc79..82ada49 100644
--- a/src/vk/character.hpp
+++ b/src/vk/character.hpp
@@ -31,8 +31,8 @@ struct Character
 {
   VkImage image;
   VkDeviceMemory device_memory;
-  uint32_t width, height, bearing_x, bearing_y, advance;
-  uint32_t mip_levels;
+  int32_t bearing_y, bearing_x;
+  uint32_t width, height, advance, mip_levels;
 
   Character(FT_Face face, uint32_t character_code);
   ~Character();
diff --git a/src/vk/texture.cpp b/src/vk/texture.cpp
index 93bfe61..c699ecc 100644
--- a/src/vk/texture.cpp
+++ b/src/vk/texture.cpp
@@ -247,12 +247,11 @@ const CommandChain image_loader{
 
 struct CharacterToDraw
 {
-  int pos_x, pos_y;
+  int pos_x;
   std::shared_ptr<VK::Character> character;
 
-  CharacterToDraw(int x, int y, std::shared_ptr<VK::Character> character):
+  CharacterToDraw(int x, std::shared_ptr<VK::Character> character):
     pos_x{x},
-    pos_y{y},
     character{character}
     {};
 };
@@ -261,6 +260,7 @@ struct TextTextureBuilder: public ImageBuilder
 {
   VK::Font *font;
   const char* str;
+  uint32_t max_bearing_y;
   std::vector<CharacterToDraw> chars_to_draw;
 
   TextTextureBuilder(VK::Texture *texture, VK::Font *font, const char* str):
@@ -276,31 +276,35 @@ load_text_proportions(void *obj)
 {
   auto self = static_cast<TextTextureBuilder*>(obj);
 
-  uint32_t texture_width, texture_height;
+  uint32_t texture_width{0}, texture_descender{0};
   auto unicode_text{VK::Character::str_to_unicode(self->str)};
 
-  texture_width = 0;
-  texture_height = 0;
+  auto first_image{self->font->character(unicode_text[0])};
+  if(first_image->bearing_x < 0) texture_width = - first_image->bearing_x;
+
+  self->max_bearing_y = 0;
   self->chars_to_draw.reserve(unicode_text.size());
   { // Calculate image size
     int max_height;
     for(auto char_code : unicode_text)
     {
-      auto char_image = self->font->character(char_code);
+      auto char_image{self->font->character(char_code)};
+      uint32_t descender{char_image->height - char_image->bearing_y};
       uint32_t pos_x{texture_width + char_image->bearing_x};
-      uint32_t pos_y{char_image->height - char_image->bearing_y};
 
-      self->chars_to_draw.emplace_back(pos_x,  pos_y, char_image);
+      if(char_image->image != VK_NULL_HANDLE)
+        self->chars_to_draw.emplace_back(pos_x, char_image);
 
-      if(char_image->height > texture_height)
-        texture_height = char_image->height;
+      if(char_image->bearing_y > self->max_bearing_y)
+        self->max_bearing_y = char_image->bearing_y;
+      if(descender > texture_descender) texture_descender = descender;
 
       texture_width += char_image->advance;
     }
   }
 
   self->texture->width = texture_width;
-  self->texture->height = texture_height;
+  self->texture->height = self->max_bearing_y + texture_descender;
   self->texture->mip_levels = 1;
 }
 
@@ -323,7 +327,7 @@ load_text_image(void *obj)
       pixels[image_coord] = 0; // Red
       pixels[image_coord + 1] = 0; // Green
       pixels[image_coord + 2] = 0; // Blue
-      pixels[image_coord + 3] = 255; // Alpha
+      pixels[image_coord + 3] = 0; // Alpha
     }
   }
   VK::SourceBuffer source_image_buffer{
@@ -392,7 +396,10 @@ load_text_image(void *obj)
         image_copy.srcSubresource = source_subresources;
         image_copy.srcOffset = {0, 0, 0};
         image_copy.dstSubresource = destination_subresources;
-        image_copy.dstOffset = {to_draw.pos_x, to_draw.pos_y, 0};
+        image_copy.dstOffset = {
+          to_draw.pos_x,
+          (int)(self->max_bearing_y - to_draw.character->bearing_y),
+          0};
         image_copy.extent = {
           to_draw.character->width, to_draw.character->height, 1};