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Merged
Overv merged 7 commits into from
Nov 3, 2022
Merged

Persistent mapping for uniform buffers #310

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bd59181
Updated UBO chapter and removed in-place map and unmap of the ubo
SaschaWillems Oct 3, 2022
1dd4c73
Fixed index for uniform buffer selection
SaschaWillems Oct 3, 2022
4381348
Update code samples to persistent ubo mapping
SaschaWillems Oct 3, 2022
a624d6e
Resize vector for mapped uniform buffer pointers
SaschaWillems Oct 3, 2022
80598c9
Use calculated buffer size for mapping
SaschaWillems Oct 3, 2022
eccadae
Update code samples to persistent ubo mapping
SaschaWillems Oct 3, 2022
30c39b1
Spelling
SaschaWillems Oct 3, 2022
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9 changes: 5 additions & 4 deletions code/22_descriptor_layout.cpp
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -159,6 +159,7 @@ class HelloTriangleApplication {

std::vector<VkBuffer> uniformBuffers;
std::vector<VkDeviceMemory> uniformBuffersMemory;
std::vector<void*> uniformBuffersMapped;

std::vector<VkCommandBuffer> commandBuffers;

Expand Down Expand Up @@ -746,9 +747,12 @@ class HelloTriangleApplication {

uniformBuffers.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMemory.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMapped.resize(MAX_FRAMES_IN_FLIGHT);

for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {
createBuffer(bufferSize, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, uniformBuffers[i], uniformBuffersMemory[i]);

vkMapMemory(device, uniformBuffersMemory[i], 0, bufferSize, 0, &uniformBuffersMapped[i]);
}
}

Expand Down Expand Up @@ -923,10 +927,7 @@ class HelloTriangleApplication {
ubo.proj = glm::perspective(glm::radians(45.0f), swapChainExtent.width / (float) swapChainExtent.height, 0.1f, 10.0f);
ubo.proj[1][1] *= -1;

void* data;
vkMapMemory(device, uniformBuffersMemory[currentImage], 0, sizeof(ubo), 0, &data);
memcpy(data, &ubo, sizeof(ubo));
vkUnmapMemory(device, uniformBuffersMemory[currentImage]);
memcpy(uniformBuffersMapped[currentImage], &ubo, sizeof(ubo));
}

void drawFrame() {
Expand Down
9 changes: 5 additions & 4 deletions code/23_descriptor_sets.cpp
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -159,6 +159,7 @@ class HelloTriangleApplication {

std::vector<VkBuffer> uniformBuffers;
std::vector<VkDeviceMemory> uniformBuffersMemory;
std::vector<void*> uniformBuffersMapped;

VkDescriptorPool descriptorPool;
std::vector<VkDescriptorSet> descriptorSets;
Expand Down Expand Up @@ -753,9 +754,12 @@ class HelloTriangleApplication {

uniformBuffers.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMemory.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMapped.resize(MAX_FRAMES_IN_FLIGHT);

for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {
createBuffer(bufferSize, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, uniformBuffers[i], uniformBuffersMemory[i]);

vkMapMemory(device, uniformBuffersMemory[i], 0, bufferSize, 0, &uniformBuffersMapped[i]);
}
}

Expand Down Expand Up @@ -981,10 +985,7 @@ class HelloTriangleApplication {
ubo.proj = glm::perspective(glm::radians(45.0f), swapChainExtent.width / (float) swapChainExtent.height, 0.1f, 10.0f);
ubo.proj[1][1] *= -1;

void* data;
vkMapMemory(device, uniformBuffersMemory[currentImage], 0, sizeof(ubo), 0, &data);
memcpy(data, &ubo, sizeof(ubo));
vkUnmapMemory(device, uniformBuffersMemory[currentImage]);
memcpy(uniformBuffersMapped[currentImage], &ubo, sizeof(ubo));
}

void drawFrame() {
Expand Down
9 changes: 5 additions & 4 deletions code/24_texture_image.cpp
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -165,6 +165,7 @@ class HelloTriangleApplication {

std::vector<VkBuffer> uniformBuffers;
std::vector<VkDeviceMemory> uniformBuffersMemory;
std::vector<void*> uniformBuffersMapped;

VkDescriptorPool descriptorPool;
std::vector<VkDescriptorSet> descriptorSets;
Expand Down Expand Up @@ -898,9 +899,12 @@ class HelloTriangleApplication {

uniformBuffers.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMemory.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMapped.resize(MAX_FRAMES_IN_FLIGHT);

for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {
createBuffer(bufferSize, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, uniformBuffers[i], uniformBuffersMemory[i]);

vkMapMemory(device, uniformBuffersMemory[i], 0, bufferSize, 0, &uniformBuffersMapped[i]);
}
}

Expand Down Expand Up @@ -1136,10 +1140,7 @@ class HelloTriangleApplication {
ubo.proj = glm::perspective(glm::radians(45.0f), swapChainExtent.width / (float) swapChainExtent.height, 0.1f, 10.0f);
ubo.proj[1][1] *= -1;

void* data;
vkMapMemory(device, uniformBuffersMemory[currentImage], 0, sizeof(ubo), 0, &data);
memcpy(data, &ubo, sizeof(ubo));
vkUnmapMemory(device, uniformBuffersMemory[currentImage]);
memcpy(uniformBuffersMapped[currentImage], &ubo, sizeof(ubo));
}

void drawFrame() {
Expand Down
9 changes: 5 additions & 4 deletions code/25_sampler.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -167,6 +167,7 @@ class HelloTriangleApplication {

std::vector<VkBuffer> uniformBuffers;
std::vector<VkDeviceMemory> uniformBuffersMemory;
std::vector<void*> uniformBuffersMapped;

VkDescriptorPool descriptorPool;
std::vector<VkDescriptorSet> descriptorSets;
Expand Down Expand Up @@ -937,9 +938,12 @@ class HelloTriangleApplication {

uniformBuffers.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMemory.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMapped.resize(MAX_FRAMES_IN_FLIGHT);

for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {
createBuffer(bufferSize, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, uniformBuffers[i], uniformBuffersMemory[i]);

vkMapMemory(device, uniformBuffersMemory[i], 0, bufferSize, 0, &uniformBuffersMapped[i]);
}
}

Expand Down Expand Up @@ -1174,10 +1178,7 @@ class HelloTriangleApplication {
ubo.proj = glm::perspective(glm::radians(45.0f), swapChainExtent.width / (float) swapChainExtent.height, 0.1f, 10.0f);
ubo.proj[1][1] *= -1;

void* data;
vkMapMemory(device, uniformBuffersMemory[currentImage], 0, sizeof(ubo), 0, &data);
memcpy(data, &ubo, sizeof(ubo));
vkUnmapMemory(device, uniformBuffersMemory[currentImage]);
memcpy(uniformBuffersMapped[currentImage], &ubo, sizeof(ubo));
}

void drawFrame() {
Expand Down
9 changes: 5 additions & 4 deletions code/26_texture_mapping.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -173,6 +173,7 @@ class HelloTriangleApplication {

std::vector<VkBuffer> uniformBuffers;
std::vector<VkDeviceMemory> uniformBuffersMemory;
std::vector<void*> uniformBuffersMapped;

VkDescriptorPool descriptorPool;
std::vector<VkDescriptorSet> descriptorSets;
Expand Down Expand Up @@ -951,9 +952,12 @@ class HelloTriangleApplication {

uniformBuffers.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMemory.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMapped.resize(MAX_FRAMES_IN_FLIGHT);

for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {
createBuffer(bufferSize, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, uniformBuffers[i], uniformBuffersMemory[i]);

vkMapMemory(device, uniformBuffersMemory[i], 0, bufferSize, 0, &uniformBuffersMapped[i]);
}
}

Expand Down Expand Up @@ -1204,10 +1208,7 @@ class HelloTriangleApplication {
ubo.proj = glm::perspective(glm::radians(45.0f), swapChainExtent.width / (float) swapChainExtent.height, 0.1f, 10.0f);
ubo.proj[1][1] *= -1;

void* data;
vkMapMemory(device, uniformBuffersMemory[currentImage], 0, sizeof(ubo), 0, &data);
memcpy(data, &ubo, sizeof(ubo));
vkUnmapMemory(device, uniformBuffersMemory[currentImage]);
memcpy(uniformBuffersMapped[currentImage], &ubo, sizeof(ubo));
}

void drawFrame() {
Expand Down
9 changes: 5 additions & 4 deletions code/27_depth_buffering.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -184,6 +184,7 @@ class HelloTriangleApplication {

std::vector<VkBuffer> uniformBuffers;
std::vector<VkDeviceMemory> uniformBuffersMemory;
std::vector<void*> uniformBuffersMapped;

VkDescriptorPool descriptorPool;
std::vector<VkDescriptorSet> descriptorSets;
Expand Down Expand Up @@ -1028,9 +1029,12 @@ class HelloTriangleApplication {

uniformBuffers.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMemory.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMapped.resize(MAX_FRAMES_IN_FLIGHT);

for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {
createBuffer(bufferSize, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, uniformBuffers[i], uniformBuffersMemory[i]);

vkMapMemory(device, uniformBuffersMemory[i], 0, bufferSize, 0, &uniformBuffersMapped[i]);
}
}

Expand Down Expand Up @@ -1284,10 +1288,7 @@ class HelloTriangleApplication {
ubo.proj = glm::perspective(glm::radians(45.0f), swapChainExtent.width / (float) swapChainExtent.height, 0.1f, 10.0f);
ubo.proj[1][1] *= -1;

void* data;
vkMapMemory(device, uniformBuffersMemory[currentImage], 0, sizeof(ubo), 0, &data);
memcpy(data, &ubo, sizeof(ubo));
vkUnmapMemory(device, uniformBuffersMemory[currentImage]);
memcpy(uniformBuffersMapped[currentImage], &ubo, sizeof(ubo));
}

void drawFrame() {
Expand Down
9 changes: 5 additions & 4 deletions code/28_model_loading.cpp
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -190,6 +190,7 @@ class HelloTriangleApplication {

std::vector<VkBuffer> uniformBuffers;
std::vector<VkDeviceMemory> uniformBuffersMemory;
std::vector<void*> uniformBuffersMapped;

VkDescriptorPool descriptorPool;
std::vector<VkDescriptorSet> descriptorSets;
Expand Down Expand Up @@ -1074,9 +1075,12 @@ class HelloTriangleApplication {

uniformBuffers.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMemory.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMapped.resize(MAX_FRAMES_IN_FLIGHT);

for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {
createBuffer(bufferSize, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, uniformBuffers[i], uniformBuffersMemory[i]);

vkMapMemory(device, uniformBuffersMemory[i], 0, bufferSize, 0, &uniformBuffersMapped[i]);
}
}

Expand Down Expand Up @@ -1330,10 +1334,7 @@ class HelloTriangleApplication {
ubo.proj = glm::perspective(glm::radians(45.0f), swapChainExtent.width / (float) swapChainExtent.height, 0.1f, 10.0f);
ubo.proj[1][1] *= -1;

void* data;
vkMapMemory(device, uniformBuffersMemory[currentImage], 0, sizeof(ubo), 0, &data);
memcpy(data, &ubo, sizeof(ubo));
vkUnmapMemory(device, uniformBuffersMemory[currentImage]);
memcpy(uniformBuffersMapped[currentImage], &ubo, sizeof(ubo));
}

void drawFrame() {
Expand Down
9 changes: 5 additions & 4 deletions code/29_mipmapping.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -191,6 +191,7 @@ class HelloTriangleApplication {

std::vector<VkBuffer> uniformBuffers;
std::vector<VkDeviceMemory> uniformBuffersMemory;
std::vector<void*> uniformBuffersMapped;

VkDescriptorPool descriptorPool;
std::vector<VkDescriptorSet> descriptorSets;
Expand Down Expand Up @@ -1168,9 +1169,12 @@ class HelloTriangleApplication {

uniformBuffers.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMemory.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMapped.resize(MAX_FRAMES_IN_FLIGHT);

for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {
createBuffer(bufferSize, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, uniformBuffers[i], uniformBuffersMemory[i]);

vkMapMemory(device, uniformBuffersMemory[i], 0, bufferSize, 0, &uniformBuffersMapped[i]);
}
}

Expand Down Expand Up @@ -1424,10 +1428,7 @@ class HelloTriangleApplication {
ubo.proj = glm::perspective(glm::radians(45.0f), swapChainExtent.width / (float) swapChainExtent.height, 0.1f, 10.0f);
ubo.proj[1][1] *= -1;

void* data;
vkMapMemory(device, uniformBuffersMemory[currentImage], 0, sizeof(ubo), 0, &data);
memcpy(data, &ubo, sizeof(ubo));
vkUnmapMemory(device, uniformBuffersMemory[currentImage]);
memcpy(uniformBuffersMapped[currentImage], &ubo, sizeof(ubo));
}

void drawFrame() {
Expand Down
9 changes: 5 additions & 4 deletions code/30_multisampling.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -196,6 +196,7 @@ class HelloTriangleApplication {

std::vector<VkBuffer> uniformBuffers;
std::vector<VkDeviceMemory> uniformBuffersMemory;
std::vector<void*> uniformBuffersMapped;

VkDescriptorPool descriptorPool;
std::vector<VkDescriptorSet> descriptorSets;
Expand Down Expand Up @@ -1218,9 +1219,12 @@ class HelloTriangleApplication {

uniformBuffers.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMemory.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMapped.resize(MAX_FRAMES_IN_FLIGHT);

for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {
createBuffer(bufferSize, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, uniformBuffers[i], uniformBuffersMemory[i]);

vkMapMemory(device, uniformBuffersMemory[i], 0, bufferSize, 0, &uniformBuffersMapped[i]);
}
}

Expand Down Expand Up @@ -1474,10 +1478,7 @@ class HelloTriangleApplication {
ubo.proj = glm::perspective(glm::radians(45.0f), swapChainExtent.width / (float) swapChainExtent.height, 0.1f, 10.0f);
ubo.proj[1][1] *= -1;

void* data;
vkMapMemory(device, uniformBuffersMemory[currentImage], 0, sizeof(ubo), 0, &data);
memcpy(data, &ubo, sizeof(ubo));
vkUnmapMemory(device, uniformBuffersMemory[currentImage]);
memcpy(uniformBuffersMapped[currentImage], &ubo, sizeof(ubo));
}

void drawFrame() {
Expand Down
17 changes: 9 additions & 8 deletions en/05_Uniform_buffers/00_Descriptor_layout_and_buffer.md
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Original file line number Diff line number Diff line change
Expand Up @@ -243,6 +243,7 @@ VkDeviceMemory indexBufferMemory;

std::vector<VkBuffer> uniformBuffers;
std::vector<VkDeviceMemory> uniformBuffersMemory;
std::vector<void*> uniformBuffersMapped;
```

Similarly, create a new function `createUniformBuffers` that is called after
Expand All @@ -264,16 +265,19 @@ void createUniformBuffers() {

uniformBuffers.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMemory.resize(MAX_FRAMES_IN_FLIGHT);
uniformBuffersMapped.resize(MAX_FRAMES_IN_FLIGHT);

for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {
createBuffer(bufferSize, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, uniformBuffers[i], uniformBuffersMemory[i]);

vkMapMemory(device, uniformBuffersMemory[i], 0, bufferSize, 0, &uniformBuffersMapped[i]);
}
}
```

We're going to write a separate function that updates the uniform buffer with a
new transformation every frame, so there will be no `vkMapMemory` here. The
uniform data will be used for all draw calls, so the buffer containing it should only be destroyed when we stop rendering.
We map the buffer right after creation using `vkMapMemory` to get a pointer to which we can write the data later on. The buffer stays mapped to this pointer for the application's whole lifetime. This technique is called **"persistent mapping"** and works on all Vulkan implementations. Not having to map the buffer every time we need to update it increases performances, as mapping is not free.

The uniform data will be used for all draw calls, so the buffer containing it should only be destroyed when we stop rendering.

```c++
void cleanup() {
Expand Down Expand Up @@ -393,13 +397,10 @@ do this, then the image will be rendered upside down.

All of the transformations are defined now, so we can copy the data in the
uniform buffer object to the current uniform buffer. This happens in exactly the same
way as we did for vertex buffers, except without a staging buffer:
way as we did for vertex buffers, except without a staging buffer. As noted earlier, we only map the uniform buffer once, so we can directly write to it without having to map again:

```c++
void* data;
vkMapMemory(device, uniformBuffersMemory[currentImage], 0, sizeof(ubo), 0, &data);
memcpy(data, &ubo, sizeof(ubo));
vkUnmapMemory(device, uniformBuffersMemory[currentImage]);
memcpy(uniformBuffersMapped[currentImage], &ubo, sizeof(ubo));
```

Using a UBO this way is not the most efficient way to pass frequently changing
Expand Down