feat Create text rendering system

1 files changed, 265 insertions, 0 deletions

diff --git a/src/vk/character.cpp b/src/vk/character.cpp
new file mode 100644
index 0000000..04ddb0c
--- /dev/null
+++ b/src/vk/character.cpp
@@ -0,0 +1,265 @@
+/*
+ * Copyright 2022-2023 Frederico de Oliveira Linhares
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "character.hpp"
+
+#include "../command.hpp"
+#include "../core.hpp"
+#include "font.hpp"
+#include "image.hpp"
+#include "source_buffer.hpp"
+
+namespace
+{
+
+struct CharacterBuilder
+{
+  VK::Character *character;
+  FT_Face face;
+  uint32_t character_code;
+
+  CharacterBuilder(
+    VK::Character *character, FT_Face face, uint32_t character_code);
+};
+
+CharacterBuilder::CharacterBuilder(
+  VK::Character *character, FT_Face face, uint32_t character_code):
+  character{character},
+  face{face},
+  character_code{character_code}
+{
+}
+
+// TODO: creating one image with one device memory for each character is
+// ineficient
+void
+load_image(void *obj)
+{
+  auto self = static_cast<CharacterBuilder*>(obj);
+
+  FT_Error error;
+  std::vector<uint8_t> source_image_raw;
+  const int num_channels = 4; // all images are converted to RGBA
+  auto glyph_index{FT_Get_Char_Index(self->face, self->character_code)};
+
+  error = FT_Load_Glyph(self->face, glyph_index, FT_LOAD_DEFAULT);
+  if(error) throw CommandError{"failed to load glyph"};
+
+  error = FT_Render_Glyph(self->face->glyph, FT_RENDER_MODE_NORMAL);
+  if(error) throw CommandError{"failed to render glyph"};
+
+  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;
+
+  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);
+
+    for(auto y{0}; y < self->face->glyph->bitmap.width; y++)
+    {
+      for(auto x{0}; x < self->face->glyph->bitmap.rows; x++)
+      {
+        auto image_coord = y * self->face->glyph->bitmap.rows * num_channels +
+          x * num_channels;
+        auto glyph_coord = y * self->face->glyph->bitmap.rows + x;
+        // Red
+        source_image_raw[image_coord] = 0;
+        // Green
+        source_image_raw[image_coord + 1] = 0;
+        // Blue
+        source_image_raw[image_coord + 2] = 0;
+        // Alpha
+        source_image_raw[image_coord + 3] =
+          self->face->glyph->bitmap.buffer[glyph_coord];
+      }
+    }
+  }
+
+  VK::SourceBuffer source_image_buffer{
+    cg_core.vk_device_with_swapchain, source_image_raw.data(),
+    image_size};
+
+  { // Create Vulkan image.
+    try
+    {
+      VkExtent3D vk_extent3d;
+      vk_extent3d.width = self->face->glyph->bitmap.width;
+      vk_extent3d.height = self->face->glyph->bitmap.rows;
+      vk_extent3d.depth = 1;
+
+      VK::Image::create(
+        cg_core.vk_device_with_swapchain,
+	&self->character->image,
+	&self->character->device_memory,
+	VK_FORMAT_R8G8B8A8_UNORM,
+	vk_extent3d,
+	self->character->mip_levels,
+	VK_IMAGE_TILING_OPTIMAL,
+	VK_IMAGE_USAGE_TRANSFER_SRC_BIT | VK_IMAGE_USAGE_TRANSFER_DST_BIT);
+    }
+    catch(VK::Image::Error error)
+    {
+      throw CommandError{error.what()};
+    }
+  }
+
+  { // Copy image from buffer into image.
+    auto queue_family{cg_core.vk_device_with_swapchain->
+      get_queue_family_with_presentation()};
+    auto queue{queue_family->get_queue()};
+    VK::CommandPool command_pool{queue_family, 1};
+    VkCommandBuffer vk_command_buffer{command_pool.command_buffers[0]};
+
+    queue.submit_one_time_command(vk_command_buffer, [&](){
+      VK::Image::move_image_state(
+        vk_command_buffer, self->character->image, VK_FORMAT_R8G8B8A8_UNORM,
+        0, VK_ACCESS_TRANSFER_WRITE_BIT, VK_IMAGE_LAYOUT_UNDEFINED,
+        VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, VK_PIPELINE_STAGE_HOST_BIT,
+        VK_PIPELINE_STAGE_TRANSFER_BIT);
+
+      VkBufferImageCopy image_copy;
+      image_copy.bufferOffset = 0;
+      image_copy.bufferRowLength = 0;
+      image_copy.bufferImageHeight = 0;
+      image_copy.imageSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
+      image_copy.imageSubresource.mipLevel = 0;
+      image_copy.imageSubresource.baseArrayLayer = 0;
+      image_copy.imageSubresource.layerCount = 1;
+      image_copy.imageOffset = {0, 0, 0};
+      image_copy.imageExtent = {
+        self->character->width, self->character->height, 1};
+
+      vkCmdCopyBufferToImage(
+        vk_command_buffer, source_image_buffer.buffer, self->character->image,
+        VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, 1, &image_copy);
+
+      VK::Image::move_image_state(
+        vk_command_buffer, self->character->image, VK_FORMAT_R8G8B8A8_UNORM,
+        VK_ACCESS_TRANSFER_WRITE_BIT, VK_ACCESS_SHADER_READ_BIT,
+        VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
+        VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL,
+        VK_PIPELINE_STAGE_TRANSFER_BIT,
+        VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT);
+    });
+  }
+}
+
+void
+unload_image(void *obj)
+{
+  auto self = static_cast<CharacterBuilder*>(obj);
+
+  vkDestroyImage(
+    cg_core.vk_device_with_swapchain->device, self->character->image, nullptr);
+  vkFreeMemory(
+    cg_core.vk_device_with_swapchain->device, self->character->device_memory,
+    nullptr);
+}
+
+const CommandChain loader{
+  {&load_image, &unload_image}
+};
+
+}
+
+namespace VK
+{
+
+Character::Character(FT_Face face, uint32_t character_code)
+{
+  CharacterBuilder character_builder(this, face, character_code);
+  loader.execute(&character_builder);
+}
+
+Character::~Character()
+{
+  CharacterBuilder character_builder(this, nullptr, 0);
+  loader.revert(&character_builder);
+}
+
+std::vector<uint32_t>
+Character::str_to_unicode(const char* str)
+{
+  std::vector<uint32_t> unicode_text;
+  int text_width{0};
+  int text_height{0};
+
+  { // Reserve memory
+    int size{0};
+    for(auto i{0}; str[i] != '\0'; i++)
+      if((str[i] & 0b11000000) != 0b10000000) size++;
+    unicode_text.reserve(size);
+  }
+
+  for(auto i{0}; str[i] != '\0'; i++)
+  {
+    int num_bytes;
+    uint32_t codepoint{0};
+
+    if(str[i] >= 0 && str[i] < 127)
+    { // Normal ASCI character, 1-byte.
+      num_bytes = 1;
+      codepoint = str[i];
+    }
+    else if((str[i] & 0xE0) == 0xC0)
+    { // 2-byte character.
+      num_bytes = 2;
+      codepoint += ((str[i] & 0b00011111) << 6);
+    }
+    else if((str[i] & 0xF0) == 0xE0)
+    { // 3-byte character.
+      num_bytes = 3;
+      codepoint += ((str[i] & 0b00001111) << 12);
+    }
+    else if((str[i] & 0xF8) == 0xF0)
+    { // 4-byte character.
+      num_bytes = 4;
+      codepoint += ((str[i] & 0b00000111) << 18);
+    }
+    else
+    { // FIXME: Add support to 5-byte and 6-byte characters.
+    }
+
+    switch (num_bytes)
+    {
+    case 4:
+      i++;
+      codepoint += ((str[i] & 0b00111111) << 12);
+    case 3:
+      i++;
+      codepoint += ((str[i] & 0b00111111) << 6);
+    case 2:
+      i++;
+      codepoint += (str[i] & 0b00111111);
+    case 1:
+    default:
+      break;
+    }
+
+    unicode_text.push_back(codepoint);
+  }
+
+  return unicode_text;
+}
+
+}