From b2b1a256fec072bac92e714f7720c19db8755cae Mon Sep 17 00:00:00 2001
From: Camden Dixie O'Brien <cobrien@witekio.com>
Date: Fri, 26 Sep 2025 12:02:44 +0100
Subject: [PATCH] Create procedure for setting up GPU buffers

---
 gpu.c | 87 ++++++++++++++++++++++++++++++++---------------------------
 1 file changed, 48 insertions(+), 39 deletions(-)

diff --git a/gpu.c b/gpu.c
index 39790d2..25fb473 100644
--- a/gpu.c
+++ b/gpu.c
@@ -47,6 +47,50 @@ load_shader_module(VkDevice dev, const char *code, size_t code_size)
 	return mod;
 }
 
+static void create_buffer(
+    const gpu_ctx_t *ctx, VkDeviceSize size, VkBufferUsageFlags usage,
+    VkMemoryPropertyFlags props, VkBuffer *buf_out, VkDeviceMemory *mem_out)
+{
+	VkResult result;
+
+	// Create buffer
+	const VkBufferCreateInfo buf_config = {
+		.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO,
+		.size = size,
+		.usage = usage,
+		.sharingMode = VK_SHARING_MODE_EXCLUSIVE,
+	};
+	result = vkCreateBuffer(ctx->dev, &buf_config, nullptr, buf_out);
+	assert(result == VK_SUCCESS);
+
+	// Find appropriate memory type
+	VkMemoryRequirements requirements;
+	vkGetBufferMemoryRequirements(ctx->dev, *buf_out, &requirements);
+	VkPhysicalDeviceMemoryProperties mem_props;
+	vkGetPhysicalDeviceMemoryProperties(ctx->physical_dev, &mem_props);
+	uint32_t mem_type = UINT32_MAX;
+	for (unsigned i = 0; i < mem_props.memoryTypeCount; ++i) {
+		if ((requirements.memoryTypeBits & (1 << i)) == 0)
+			continue;
+		if ((mem_props.memoryTypes[i].propertyFlags & props) == props) {
+			mem_type = i;
+			break;
+		}
+	}
+	assert(mem_type != UINT32_MAX);
+
+	// Allocate memory
+	VkMemoryAllocateInfo allocate_config = {
+		.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO,
+		.allocationSize = requirements.size,
+		.memoryTypeIndex = mem_type,
+	};
+	result = vkAllocateMemory(ctx->dev, &allocate_config, nullptr, mem_out);
+	assert(result == VK_SUCCESS);
+
+	vkBindBufferMemory(ctx->dev, *buf_out, *mem_out, 0);
+}
+
 void gpu_init(gpu_ctx_t *ctx, const gpu_config_t *config)
 {
 	// Initialise Vulkan instance.
@@ -435,47 +479,12 @@ void gpu_init(gpu_ctx_t *ctx, const gpu_config_t *config)
 
 	// Create vertex buffer
 	ctx->vertex_data_size = config->vertex_data_size;
-	const VkBufferCreateInfo vertex_buf_config = {
-		.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO,
-		.size = ctx->vertex_data_size,
-		.usage = VK_BUFFER_USAGE_VERTEX_BUFFER_BIT,
-		.sharingMode = VK_SHARING_MODE_EXCLUSIVE,
-	};
-	result = vkCreateBuffer(
-	    ctx->dev, &vertex_buf_config, nullptr, &ctx->vertex_buf);
-	assert(result == VK_SUCCESS);
-
-	// Allocate memory to vertex buffer
-	const VkMemoryPropertyFlags mem_flags
+	const VkMemoryPropertyFlags vertex_buf_props
 	    = VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT
 	    | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT;
-	VkMemoryRequirements mem_requirements;
-	vkGetBufferMemoryRequirements(
-	    ctx->dev, ctx->vertex_buf, &mem_requirements);
-	VkPhysicalDeviceMemoryProperties mem_props;
-	vkGetPhysicalDeviceMemoryProperties(ctx->physical_dev, &mem_props);
-	uint32_t mem_type = UINT32_MAX;
-	for (unsigned i = 0; i < mem_props.memoryTypeCount; ++i) {
-		const bool valid_type
-		    = (mem_requirements.memoryTypeBits & (1 << i)) != 0;
-		const bool has_flags
-		    = (mem_props.memoryTypes[i].propertyFlags & mem_flags)
-		    == mem_flags;
-		if (valid_type && has_flags) {
-			mem_type = i;
-			break;
-		}
-	}
-	assert(mem_type != UINT32_MAX);
-	VkMemoryAllocateInfo allocate_config = {
-		.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO,
-		.allocationSize = mem_requirements.size,
-		.memoryTypeIndex = mem_type,
-	};
-	result = vkAllocateMemory(
-	    ctx->dev, &allocate_config, nullptr, &ctx->vertex_buf_mem);
-	assert(result == VK_SUCCESS);
-	vkBindBufferMemory(ctx->dev, ctx->vertex_buf, ctx->vertex_buf_mem, 0);
+	create_buffer(
+	    ctx, ctx->vertex_data_size, VK_BUFFER_USAGE_VERTEX_BUFFER_BIT,
+	    vertex_buf_props, &ctx->vertex_buf, &ctx->vertex_buf_mem);
 
 	// Copy vertex data into vertex buffer
 	void *vertex_buf_ptr;