From 068bc2213b17d2020202d4cba60858dfeb96b23d Mon Sep 17 00:00:00 2001
From: Noah Metz <noah@metznet.ca>
Date: Tue, 15 Oct 2024 11:44:59 -0600
Subject: [PATCH] Create draw buffer

---
 client/include/pipeline.h      |  8 ++++++++
 client/shader_src/ui_text.comp | 17 ++++++++++++++++-
 client/src/main.c              | 24 ++++++++++++++++++++++++
 3 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/client/include/pipeline.h b/client/include/pipeline.h
index 3fc34c0..da99e13 100644
--- a/client/include/pipeline.h
+++ b/client/include/pipeline.h
@@ -34,10 +34,18 @@ typedef struct TextStruct {
   uint32_t offset;
 } Text;
 
+typedef struct DrawCommandStruct {
+  uint32_t vertex_count;
+  uint32_t instance_count;
+  uint32_t first_vertex;
+  uint32_t first_instance;
+} DrawCommand;
+
 typedef struct TextPointersStruct {
   VkDeviceAddress strings;
   VkDeviceAddress codes;
   VkDeviceAddress characters;
+  VkDeviceAddress draw;
 } TextPointers;
 
 typedef struct CharStruct {
diff --git a/client/shader_src/ui_text.comp b/client/shader_src/ui_text.comp
index 3b38843..eac5182 100644
--- a/client/shader_src/ui_text.comp
+++ b/client/shader_src/ui_text.comp
@@ -19,7 +19,7 @@ struct String {
   vec4 color;
   float size;
   uint offset;
-  uint length;
+  uint len;
 };
 
 layout(buffer_reference, std430) readonly buffer SymbolList{ 
@@ -46,15 +46,30 @@ layout(set = 0, binding = 0) uniform Font {
   SymbolList symbol_list;
 } font;
 
+layout(buffer_reference, std430) buffer DrawCommand {
+  uint vertex_count;
+  uint instance_count;
+  uint first_vertx;
+  uint first_instance;
+};
+
 layout(buffer_reference, std430) readonly buffer Pointers {
   Strings strings;
   Characters codes;
   CharacterList characters;
+  DrawCommand draw;
 };
 
 layout(std430, push_constant) uniform Push {
   Pointers pointers;
 } push;
 
+layout(local_size_x = 1) in;
+
 void main() {
+  uint gID = gl_GlobalInvocationID.x;
+  String string = push.pointers.strings.strings[gID];
+
+  uint buffer_pos = atomicAdd(push.pointers.draw.instance_count, string.len);
+  // Write the characters to push.pointers.characters.characters[buffer_pos:buffer_pos+string.len)
 }
diff --git a/client/src/main.c b/client/src/main.c
index 44b5c5c..155148c 100644
--- a/client/src/main.c
+++ b/client/src/main.c
@@ -197,6 +197,25 @@ VkResult render_thread(GLFWwindow* window, RenderContext* render_context) {
 
   vmaUnmapMemory(render_context->allocator, text_memory);
 
+  VkBuffer draw_buffer;
+  VmaAllocation draw_memory;
+
+  VkBufferCreateInfo draw_buffer_info = {
+    .sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO,
+    .usage = VK_BUFFER_USAGE_STORAGE_BUFFER_BIT | VK_BUFFER_USAGE_SHADER_DEVICE_ADDRESS_BIT,
+    .size = sizeof(DrawCommand),
+    .sharingMode = VK_SHARING_MODE_EXCLUSIVE,
+  };
+
+  VmaAllocationCreateInfo draw_memory_info = {
+    .usage = VMA_MEMORY_USAGE_GPU_ONLY,
+  };
+
+  result = vmaCreateBuffer(render_context->allocator, &draw_buffer_info, &draw_memory_info, &draw_buffer, &draw_memory, NULL);
+  if(result != VK_SUCCESS) {
+    return result;
+  }
+
   VkBuffer text_pointer_buffer;
   VmaAllocation text_pointer_memory;
 
@@ -227,6 +246,11 @@ VkResult render_thread(GLFWwindow* window, RenderContext* render_context) {
     .buffer = text_buffer,
   };
   pointers->characters = vkGetBufferDeviceAddress(render_context->device, &test_address_info);
+  VkBufferDeviceAddressInfo draw_address_info = {
+    .sType = VK_STRUCTURE_TYPE_BUFFER_DEVICE_ADDRESS_INFO,
+    .buffer = draw_buffer,
+  };
+  pointers->draw = vkGetBufferDeviceAddress(render_context->device, &draw_address_info);
   vmaUnmapMemory(render_context->allocator, text_pointer_memory);
 
   VkBufferDeviceAddressInfo pointers_address_info = {