From de597ebc5d41f78a91ec4caca6e3b201a6f0de10 Mon Sep 17 00:00:00 2001
From: Piotr Krygier <piotrkrygier@everyonecancode@xyz>
Date: Tue, 10 Feb 2026 19:07:40 +0100
Subject: [PATCH] Replace uniform with storage buffer for instances

Signed-off-by: Piotr Krygier <piotrkrygier@everyonecancode@xyz>
---
 graphics/shaders/shader.vert  |  6 ++----
 graphics/src/rse_graphics.c   |  7 +++----
 graphics/src/vulkan_buffers.c | 15 +++++++++++----
 3 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/graphics/shaders/shader.vert b/graphics/shaders/shader.vert
index da23d7a0..df229617 100644
--- a/graphics/shaders/shader.vert
+++ b/graphics/shaders/shader.vert
@@ -6,8 +6,6 @@ layout(push_constant) uniform pc {
     mat4 proj;
 } ubo;
 
-#define MAX_INSTANCES 1024
-
 struct InstanceData
 {
     vec3 pos;
@@ -16,8 +14,8 @@ struct InstanceData
     uint texture_id;
 };
 
-layout(binding = 0) uniform InstanceUniformBuffer {
-    InstanceData instances[MAX_INSTANCES];
+layout(set=0, binding = 0, std430) readonly buffer InstanceBuffer {
+    InstanceData instances[];
 };
 
 layout(location = 0) in vec3 inPosition;
diff --git a/graphics/src/rse_graphics.c b/graphics/src/rse_graphics.c
index 501d0e72..1e7df270 100644
--- a/graphics/src/rse_graphics.c
+++ b/graphics/src/rse_graphics.c
@@ -5,7 +5,6 @@
 #include <SDL3/SDL_render.h>
 #include <cglm/util.h>
 #include <stdint.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
 #include <vulkan/vulkan_core.h>
@@ -203,14 +202,14 @@ rse_err_t rse_graphics_test_function(struct rse_graphics_context_t* rse_context)
 
     STATUS_CHECK(sampler_create(context, &context->vulkan_handles.sampler));
 
-    STATUS_CHECK(descriptor_pool_add_type(context, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1));
+    STATUS_CHECK(descriptor_pool_add_type(context, VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 1));
     STATUS_CHECK(descriptor_pool_add_type(context, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, TEXTURES_COUNT));
     STATUS_CHECK(descriptor_pool_initialize(context));
 
     /* Normal rendering */
     STATUS_CHECK(descriptor_create_new_set(context, &descriptor_set_handle));
     STATUS_CHECK(
-        descriptor_add_layout(&layout_bindings, 0, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1, VK_SHADER_STAGE_VERTEX_BIT));
+        descriptor_add_layout(&layout_bindings, 0, VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 1, VK_SHADER_STAGE_VERTEX_BIT));
     STATUS_CHECK(descriptor_add_layout(&layout_bindings,
                                        1,
                                        VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
@@ -223,7 +222,7 @@ rse_err_t rse_graphics_test_function(struct rse_graphics_context_t* rse_context)
                                           descriptor_set_handle,
                                           &context->render_targets[RENDER_TARGET_3D].instance_buffer,
                                           0,
-                                          VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER));
+                                          VK_DESCRIPTOR_TYPE_STORAGE_BUFFER));
 
     STATUS_CHECK(descriptor_attach_images(context,
                                           descriptor_set_handle,
diff --git a/graphics/src/vulkan_buffers.c b/graphics/src/vulkan_buffers.c
index bd44f3ca..88968274 100644
--- a/graphics/src/vulkan_buffers.c
+++ b/graphics/src/vulkan_buffers.c
@@ -119,7 +119,12 @@ static rse_err_t create_instance_buffers(struct graphics_context_t* context)
     buffer_size = sizeof(struct instance_data_t) * MAX_INSTANCE_NUMBER;
 
     STATUS_CHECK(
-        buffer_create_uniform(context, &context->render_targets[RENDER_TARGET_3D].instance_buffer, buffer_size));
+        create_buffer(context,
+                      buffer_size,
+                      VK_BUFFER_USAGE_STORAGE_BUFFER_BIT,
+                      VMA_MEMORY_USAGE_AUTO_PREFER_HOST,
+                      VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT | VMA_ALLOCATION_CREATE_MAPPED_BIT,
+                      &context->render_targets[RENDER_TARGET_3D].instance_buffer));
     /* TODO: Move creation to somewhere else? */
     STATUS_CHECK(create_buffer(context,
                                CMD_BUFFER_SIZE,
@@ -435,10 +440,12 @@ void destroy_buffers(struct graphics_context_t* context)
     destroy_buffer(context, &context->render_targets[RENDER_TARGET_3D].vertex_buffer);
     destroy_buffer(context, &context->render_targets[RENDER_TARGET_3D].index_buffer);
     destroy_buffer(context, &context->render_targets[RENDER_TARGET_3D].draw_indirect_command_buffer);
+    destroy_buffer(context, &context->render_targets[RENDER_TARGET_3D].instance_buffer);
 
-    for (iter = 0U; iter < context->uniform_buffers.vulkan_buffers_count; ++iter)
-    {
-        vmaDestroyBuffer(context->vulkan_handles.allocator, context->uniform_buffers.vulkan_buffers[iter].buffer, context->uniform_buffers.vulkan_buffers[iter].allocation);
+    for (iter = 0U; iter < context->uniform_buffers.vulkan_buffers_count; ++iter) {
+        vmaDestroyBuffer(context->vulkan_handles.allocator,
+                         context->uniform_buffers.vulkan_buffers[iter].buffer,
+                         context->uniform_buffers.vulkan_buffers[iter].allocation);
     }
 
     context->uniform_buffers.vulkan_buffers_count = 0;