vk-bootstrap/README.md
2021-03-30 09:51:56 -06:00

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# `vk-bootstrap`
A utility library that jump starts initialization of Vulkan
This library simplifies the tedious process of:
* Instance creation
* Physical Device selection
* Device creation
* Getting queues
* Swapchain creation
It also adds several conveniences for:
* Enabling validation layers
* Adding a debug callback messenger
* Enabling extensions on a physical device
* Select a gpu based on a set of criteria like features, extensions, memory, etc
Read the [Getting Started](docs/getting_started.md) guide for a quick start on using `vk-bootstrap`
## Basic Usage
```cpp
#include "VkBootstrap.h"
bool init_vulkan () {
vkb::InstanceBuilder builder;
auto inst_ret = builder.set_app_name ("Example Vulkan Application")
.request_validation_layers ()
.use_default_debug_messenger ()
.build ();
if (!inst_ret) {
std::cerr << "Failed to create Vulkan instance. Error: " << inst_ret.error().message() << "\n";
return false;
}
vkb::Instance vkb_inst = inst_ret.value ();
vkb::PhysicalDeviceSelector selector{ vkb_inst };
auto phys_ret = selector.set_surface (/* from user created window*/)
.set_minimum_version (1, 1) // require a vulkan 1.1 capable device
.require_dedicated_transfer_queue ()
.select ();
if (!phys_ret) {
std::cerr << "Failed to select Vulkan Physical Device. Error: " << phys_ret.error().message() << "\n";
return false;
}
vkb::DeviceBuilder device_builder{ phys_ret.value () };
// automatically propagate needed data from instance & physical device
auto dev_ret = device_builder.build ();
if (!dev_ret) {
std::cerr << "Failed to create Vulkan device. Error: " << dev_ret.error().message() << "\n";
return false;
}
vkb::Device vkb_device = dev_ret.value ();
// Get the VkDevice handle used in the rest of a vulkan application
VkDevice device = vkb_device.device;
// Get the graphics queue with a helper function
auto graphics_queue_ret = vkb_device.get_queue (vkb::QueueType::graphics);
if (!graphics_queue_ret) {
std::cerr << "Failed to get graphics queue. Error: " << graphics_queue_ret.error().message() << "\n";
return false;
}
VkQueue graphics_queue = graphics_queue_ret.value ();
// Turned 400-500 lines of boilerplate into less than fifty.
return true;
}
```
See `example/triangle.cpp` for an example that renders a triangle to the screen.
## Setting up `vk-bootstrap`
This library has no external dependencies beyond C++14, its standard library, and the Vulkan Headers.
Note: on Unix platforms, `vk-bootstrap` will require the dynamic linker in order to compile as the library doesn't link against `vulkan-1.dll`/`libvulkan.so` directly.
### Copy-Paste
Copy the `src/VkBootstrap.h` and `src/VkBootstrap.cpp` files into your project, include them into your build, then compile as you normally would.
`vk-bootstrap` is *not* a header only library, so no need to worry about macros in the header.
### git-submodule + CMake
Add this project as a git-submodule into the root directory. Suggested is using a subdirectory to hold all submodules.
```bash
git submodule add https://github.com/charles-lunarg/vk-bootstrap
```
With CMake, add the subdirectory to include the project
```cmake
add_subdirectory(vk-bootstrap)
```
Then use `target_link_libraries` to use the library in whichever target needs it.
```cmake
target_link_libraries(your_application_name vk-bootstrap)
```
### CMake Fetch Content
If cmake 3.12 is available, use the FetchContent capability of cmake to directly download and build the library for you.
```cmake
include(FetchContent)
FetchContent_Declare(
fetch_vk_bootstrap
GIT_REPOSITORY https://github.com/charles-lunarg/vk-bootstrap
GIT_TAG BRANCH_OR_TAG #suggest using a tag so the library doesn't update whenever new commits are pushed to a branch
)
FetchContent_MakeAvailable(fetch_vk_bootstrap)
target_link_libraries(your_application_name vk-bootstrap)
```
### Manually Building
```bash
git clone https://github.com/charles-lunarg/vk-bootstrap
cd vk-bootstrap
mkdir build
cd build
cmake ..
```
### Vulkan-Headers dependency
By default, when using vk-bootstrap through CMake, it will attempt to locate the Vulkan-Headers on the system and fall back to downloading them directly if they aren't present. If the `VK_BOOTSTRAP_VULKAN_HEADER_DIR` option is specified, it will use that directory instead.
### Testing
Tests will be enabled if you open this project standalone. If you include this project as a subdirectory or sub-project, you can force enable tests by setting the option `VK_BOOTSTRAP_TEST` to `ON`. Testing requires GLFW and Catch2 but are acquired automatically using cmake fetch content.
```bash
cmake ../path/to/your_project/ -DVK_BOOTSTRAP_TEST=ON
```
### Build Options
| Name | Type | Default Value | Description |
| ---- | --- | ---- | ----- |
| `VK_BOOTSTRAP_TEST` | bool | `OFF` | Enable building of the tests in this project. Will download GLFW and Catch2 automatically if enabled. |
| `VK_BOOTSTRAP_VULKAN_HEADER_DIR` | string | `""` | Optional. Specify the directory that contains the Vulkan Headers. Useful if you are downloading the headers manually and don't want vk-bootstrap to download them itself. |