rebuild instance buffers as they become oversized

1 files changed, 111 insertions, 2 deletions

diff --git a/src/entities.cpp b/src/entities.cpp
index f61927a..a9108a0 100644
--- a/src/entities.cpp
+++ b/src/entities.cpp
@@ -1,6 +1,7 @@
 
 #include "entities.hpp"
 
+#include <vulkan/vulkan_core.h>
 DynArray<EntityType> GlobalEntityTypes{16};
 
 void EntityType_Init() {
@@ -597,8 +598,10 @@ void EntityType_Load(EntityType &et) {
 		}
 
 		// set up instance buffer
-		bufferCI.size = sizeof(InstPos) * et.startingInstanceCount;
-		bufferCI.usage = VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_BUFFER_USAGE_VERTEX_BUFFER_BIT;
+		grBinds.instanceBufferMaxCount = et.startingInstanceCount;
+		grBinds.instanceBufferMaxCount = grBinds.instanceBufferMaxCount < 1 ? 1 : grBinds.instanceBufferMaxCount;
+		bufferCI.size = sizeof(glm::mat4) * grBinds.instanceBufferMaxCount;
+		bufferCI.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_BUFFER_USAGE_VERTEX_BUFFER_BIT;
 		vkCreateBuffer(vkDevice, &bufferCI, vkAllocator, &grBinds.instanceBuffer);
 		VkMemoryRequirements vkMemoryRequirementsInst;
 		vkGetBufferMemoryRequirements(vkDevice, grBinds.instanceBuffer, &vkMemoryRequirementsInst);
@@ -613,6 +616,112 @@ void EntityType_Load(EntityType &et) {
 	}
 }
 
+void EntityType_Tick_Late(double delta) {
+	while (EntitiesWithExcessInstances.Count() != 0) {
+		auto entHandle = EntitiesWithExcessInstances.Pop();
+		auto index = EntityType_FindByEntityHandle(entHandle);
+		auto &et = GlobalEntityTypes[index];
+		auto &grBinds = *ECS_GetGrBinds(entHandle);
+		EntityType_RolloverInstances(et, grBinds);
+	}
+}
+
+void EntityType_RolloverInstances(EntityType &et, CompGrBinds &grBinds) {
+	int32_t oldCount = grBinds.instanceBufferMaxCount;
+	int32_t newCount = std::ceil(grBinds.instanceBufferMaxCount * 1.5);
+	newCount = newCount < 4 ? 4 : newCount;
+	grBinds.instanceBufferMaxCount = newCount;
+	uint32_t oldSize = sizeof(glm::mat4) * oldCount;
+
+	VkDeviceMemory oldMemory(et.deviceMemoryInst);
+	VkBuffer oldBuffer(grBinds.instanceBuffer);
+
+	VkBufferCreateInfo vkBufferCreateInfo{};
+	vkBufferCreateInfo.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
+	vkBufferCreateInfo.pNext = nullptr;
+	vkBufferCreateInfo.flags = 0;
+	vkBufferCreateInfo.size = sizeof(glm::mat4) * newCount;
+	vkBufferCreateInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_BUFFER_USAGE_VERTEX_BUFFER_BIT;
+	vkBufferCreateInfo.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
+	vkBufferCreateInfo.queueFamilyIndexCount = 1;
+	vkBufferCreateInfo.pQueueFamilyIndices = &graphicsFamilyIndex;
+	vkCreateBuffer(vkDevice, &vkBufferCreateInfo, vkAllocator, &grBinds.instanceBuffer);
+
+	VkMemoryRequirements vkMemoryRequirementsInst;
+	vkGetBufferMemoryRequirements(vkDevice, grBinds.instanceBuffer, &vkMemoryRequirementsInst);
+
+	VkMemoryAllocateInfo vkMemoryAllocateInfo;
+	vkMemoryAllocateInfo.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
+	vkMemoryAllocateInfo.pNext = nullptr;
+	vkMemoryAllocateInfo.allocationSize = vkMemoryRequirementsInst.size;
+	vkMemoryAllocateInfo.memoryTypeIndex = FindMemoryTypeIndex(vkMemoryRequirementsInst.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
+	vkAllocateMemory(vkDevice, &vkMemoryAllocateInfo, vkAllocator, &et.deviceMemoryInst);
+
+	vkBindBufferMemory(vkDevice, grBinds.instanceBuffer, et.deviceMemoryInst, 0);
+
+	// copy data
+	{
+		vkResetCommandBuffer(graphicsCommandBuffer, 0);
+		VkBufferMemoryBarrier memBarriers[2];
+		for (long i = 0; i < 2; ++i) {
+			memBarriers[i].sType = VK_STRUCTURE_TYPE_BUFFER_MEMORY_BARRIER;
+			memBarriers[i].pNext = nullptr;
+		}
+
+		memBarriers[0].srcAccessMask = VK_ACCESS_TRANSFER_READ_BIT;
+		memBarriers[0].dstAccessMask = {};
+		memBarriers[0].srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
+		memBarriers[0].dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
+		memBarriers[0].buffer = oldBuffer;
+		memBarriers[0].offset = 0;
+		memBarriers[0].size = oldSize;
+
+		memBarriers[1].srcAccessMask = {};
+		memBarriers[1].dstAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
+		memBarriers[1].srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
+		memBarriers[1].dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
+		memBarriers[1].buffer = grBinds.instanceBuffer;
+		memBarriers[1].offset = 0;
+		memBarriers[1].size = vkMemoryRequirementsInst.size;
+
+		VkCommandBufferBeginInfo vkCommandBufferBeginInfo;
+		vkCommandBufferBeginInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
+		vkCommandBufferBeginInfo.pNext = nullptr;
+		// TODO consider single-use?
+		vkCommandBufferBeginInfo.flags = 0;
+		vkCommandBufferBeginInfo.pInheritanceInfo = nullptr;
+
+		vkBeginCommandBuffer(graphicsCommandBuffer, &vkCommandBufferBeginInfo);
+		vkCmdPipelineBarrier(graphicsCommandBuffer, VK_PIPELINE_STAGE_TRANSFER_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT, 0, 0, nullptr, 2, memBarriers, 0, nullptr);
+
+		VkBufferCopy vkBufferCopy;
+		vkBufferCopy.srcOffset = 0;
+		vkBufferCopy.dstOffset = 0;
+		vkBufferCopy.size = oldSize;
+		vkCmdCopyBuffer(graphicsCommandBuffer, oldBuffer, grBinds.instanceBuffer, 1, &vkBufferCopy);
+
+		vkEndCommandBuffer(graphicsCommandBuffer);
+
+		VkSubmitInfo submitInfo;
+		submitInfo.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
+		submitInfo.pNext = nullptr;
+		submitInfo.waitSemaphoreCount = 0;
+		submitInfo.pWaitSemaphores = nullptr;
+		submitInfo.pWaitDstStageMask = nullptr;
+		submitInfo.commandBufferCount = 1;
+		submitInfo.pCommandBuffers = &graphicsCommandBuffer;
+		submitInfo.signalSemaphoreCount = 0;
+		submitInfo.pSignalSemaphores = nullptr;
+		vkQueueSubmit(graphicsQueue, 1, &submitInfo, nullptr);
+		vkQueueWaitIdle(graphicsQueue);
+		vkResetCommandBuffer(graphicsCommandBuffer, 0);
+	}
+
+	// cleanup
+	vkDestroyBuffer(vkDevice, oldBuffer, vkAllocator);
+	vkFreeMemory(vkDevice, oldMemory, vkAllocator);
+}
+
 void EntityType_Teardown() {
 	long entityTypeCount = GlobalEntityTypes.Count();
 	for (long i = 0; i < entityTypeCount; ++i) {