image_utils

Functions

size_t GetImageByteSize (vk::Format format, size_t width, size_t height)

Defined at line 40 of file ../../src/ui/lib/escher/util/image_utils.cc

```
size_t BytesPerPixel (vk::Format format)
```
Returns the number of bytes per pixel for the given format.

Defined at line 62 of file ../../src/ui/lib/escher/util/image_utils.cc
```
bool IsDepthFormat (vk::Format format)
```
Return true if |format| can be used as a depth buffer.

Defined at line 81 of file ../../src/ui/lib/escher/util/image_utils.cc
```
bool IsStencilFormat (vk::Format format)
```
Return true if |format| can be used as a stencil buffer.

Defined at line 95 of file ../../src/ui/lib/escher/util/image_utils.cc
```
bool IsYuvFormat (vk::Format format)
```
Return true is |format| is one of the formats that Escher can treat as a YUV format.

Currently these include:

- eG8B8G8R8422Unorm

- eG8B8R82Plane420Unorm

TODO(https://fxbug.dev/42098808): use of these formats is not enough to assume NV12, but they're currently

the only formats we support at the sampler level.

Defined at line 124 of file ../../src/ui/lib/escher/util/image_utils.cc
```
std::pair<bool, bool> IsDepthStencilFormat (vk::Format format)
```
Return a pair of booleans, each of which is true if |format| can be used as

a depth or stencil buffer, respectively.

Defined at line 107 of file ../../src/ui/lib/escher/util/image_utils.cc
```
vk::ImageAspectFlags FormatToColorOrDepthStencilAspectFlags (vk::Format format)
```
If |format| is a depth-stencil format, return the appropriate combination

of eDepth and eStencil bits. Otherwise, treat it as a color format, and

return eColor.

Defined at line 136 of file ../../src/ui/lib/escher/util/image_utils.cc

vk::ImageCreateInfo CreateVkImageCreateInfo (const ImageInfo & info, vk::ImageLayout initial_layout)

Defined at line 154 of file ../../src/ui/lib/escher/util/image_utils.cc

```
vk::Image CreateVkImage (const vk::Device & device, const ImageInfo & info, vk::ImageLayout initial_layout)
```
Helper function that creates a VkImage given the parameters in ImageInfo.

This does not bind the VkImage to memory; the caller must do that

separately after calling this function.

Defined at line 179 of file ../../src/ui/lib/escher/util/image_utils.cc
```
ImagePtr NewDepthImage (ImageFactory * image_factory, vk::Format format, uint32_t width, uint32_t height, vk::ImageUsageFlags additional_flags)
```
Return a new Image that is suitable for use as a depth attachment.

|image_factory| is a generic interface that could be an Image cache (in which

case a new Image might be created, or an existing one reused). Alternatively

the factory could allocate a new Image every time.

Defined at line 186 of file ../../src/ui/lib/escher/util/image_utils.cc
```
ImagePtr NewColorAttachmentImage (ImageFactory * image_factory, uint32_t width, uint32_t height, vk::ImageUsageFlags additional_flags)
```
Return a new Image that is suitable for use as a color attachment.

|image_factory| is a generic interface that could be an Image cache (in which

case a new Image might be created, or an existing one reused). Alternatively

the factory could allocate a new Image every time.

Defined at line 200 of file ../../src/ui/lib/escher/util/image_utils.cc
```
ImagePtr NewImage (const vk::Device & device, const vk::ImageCreateInfo & create_info, escher::GpuMemPtr gpu_mem, escher::ResourceRecycler * resource_recycler)
```
Returns new image bound to the provided gpu memory, with the specified create info. This

should only be called in a scenario where we know the |gpu_mem| buffer passed in will be

compatible with the Vulkan image memory requirements such as being of a sufficiently large

size to back the image. Otherwise, this function returns nullptr.

Defined at line 214 of file ../../src/ui/lib/escher/util/image_utils.cc
```
ImagePtr NewImage (ImageFactory * image_factory, vk::Format format, ColorSpace color_space, uint32_t width, uint32_t height, vk::ImageUsageFlags additional_flags, vk::MemoryPropertyFlags memory_flags)
```
Return new Image containing the provided pixels. Uses transfer queue to

efficiently transfer image data to GPU.

|image_factory| is a generic interface that could be an Image cache (in which

case a new Image might be created, or an existing one reused). Alternatively

the factory could allocate a new Image every time.

Defined at line 248 of file ../../src/ui/lib/escher/util/image_utils.cc
```
void WritePixelsToImage (escher::BatchGpuUploader * batch_gpu_uploader, const uint8_t * pixels, const ImagePtr & gpu_image, vk::ImageLayout final_layout, const escher::image_utils::ImageConversionFunction & convertion_func)
```
Write the contents of |pixels| into an existing |gpu_image|.

The width, and height of |pixels| is assumed to match that of

|gpu_image|.

If the format of |pixels| is different from |gpu_image|, a conversion

function that can convert from |pixels| to |gpu_image| should be

provided as |convertion_func|.

Note that all escher images are stored in GPU memory. The use of gpu_image

here is to specifically differentiate it from pixels, which may be stored in

host_memory.

Defined at line 269 of file ../../src/ui/lib/escher/util/image_utils.cc
```
ImagePtr NewRgbaImage (ImageFactory * image_factory, BatchGpuUploader * gpu_uploader, uint32_t width, uint32_t height, const uint8_t * bytes, vk::ImageLayout final_layout)
```
Return new Image containing the provided pixels. Uses transfer queue to

efficiently transfer image data to GPU. If bytes is null, don't bother

transferring.

|image_factory| is a generic interface that could be an Image cache (in which

case a new Image might be created, or an existing one reused). Alternatively

the factory could allocate a new Image every time.

Defined at line 298 of file ../../src/ui/lib/escher/util/image_utils.cc
```
ImagePtr NewCheckerboardImage (ImageFactory * image_factory, BatchGpuUploader * gpu_uploader, uint32_t width, uint32_t height)
```
Returns RGBA image.

|image_factory| is a generic interface that could be an Image cache (in which

case a new Image might be created, or an existing one reused). Alternatively

the factory could allocate a new Image every time.

Defined at line 310 of file ../../src/ui/lib/escher/util/image_utils.cc
```
ImagePtr NewGradientImage (ImageFactory * image_factory, BatchGpuUploader * gpu_uploader, uint32_t width, uint32_t height)
```
Returns RGBA image.

|image_factory| is a generic interface that could be an Image cache (in which

case a new Image might be created, or an existing one reused). Alternatively

the factory could allocate a new Image every time.

Defined at line 323 of file ../../src/ui/lib/escher/util/image_utils.cc
```
ImagePtr NewNoiseImage (ImageFactory * image_factory, BatchGpuUploader * gpu_uploader, uint32_t width, uint32_t height, vk::ImageUsageFlags additional_flags)
```
Returns single-channel luminance image containing white noise.

|image_factory| is a generic interface that could be an Image cache (in which

case a new Image might be created, or an existing one reused). Alternatively

the factory could allocate a new Image every time.

Defined at line 336 of file ../../src/ui/lib/escher/util/image_utils.cc
```
std::unique_ptr<uint8_t[]> NewCheckerboardPixels (uint32_t width, uint32_t height, size_t * out_size)
```
Return RGBA pixels containing a checkerboard pattern, where each white/black

region is a single pixel. Only works for even values of width/height.

Defined at line 349 of file ../../src/ui/lib/escher/util/image_utils.cc
```
std::unique_ptr<uint8_t[]> NewGradientPixels (uint32_t width, uint32_t height, size_t * out_size)
```
Return RGBA pixels containing a gradient where the top row is white and the

bottom row is black. Only works for even values of width/height.

Defined at line 373 of file ../../src/ui/lib/escher/util/image_utils.cc
```
std::unique_ptr<uint8_t[]> NewNoisePixels (uint32_t width, uint32_t height, size_t * out_size)
```
Return eR8Unorm pixels containing random noise.

Defined at line 398 of file ../../src/ui/lib/escher/util/image_utils.cc
```
vk::ImageCreateInfo GetDefaultImageConstraints (const vk::Format & vk_format)
```
Creates a vk::ImageCreateInfo with common default values and |vk_format|.

Defined at line 425 of file ../../src/ui/lib/escher/util/image_utils.cc

vk::FormatFeatureFlags GetFormatFeatureFlagsFromUsage (vk::ImageUsageFlags usage)

Defined at line 441 of file ../../src/ui/lib/escher/util/image_utils.cc