HelixToolkit.Nex.Textures 1.2.0

# HelixToolkit.Nex.Textures

The `HelixToolkit.Nex.Textures` package is a comprehensive suite for handling texture data within the HelixToolkit-Nex 3D graphics engine. It provides functionality for loading, manipulating, and saving various image formats, as well as creating GPU textures from CPU-side image data. This package is essential for developers working with textures in 3D graphics applications using the HelixToolkit-Nex engine.

## Overview

The `HelixToolkit.Nex.Textures` package is responsible for:
- Loading and saving image data in multiple formats (e.g., DDS, PNG, JPG).
- Managing pixel data with the `Image` class, which acts as a container for texture data.
- Providing utilities for creating GPU textures from images.
- Supporting operations like mipmap generation and texture dimension management.
- Offering a fluent API for combining multiple images into a single texture using the `OmrTextureCombiner`.

This package integrates seamlessly with the HelixToolkit-Nex engine, leveraging its ECS architecture and rendering capabilities to manage textures efficiently.

## Key Types

| Type                 | Description                                                                      |
| -------------------- | -------------------------------------------------------------------------------- |
| `ChannelComponent`   | Enum identifying a single color channel within a pixel.                          |
| `ChannelSource`      | Abstract class describing the source of a channel value for texture combination. |
| `DDSCodec`           | Internal static class for handling DDS image format encoding and decoding.       |
| `IImageDecoder`      | Interface for pluggable image decoders/encoders.                                 |
| `Image`              | Class representing a CPU-side container for pixel data.                          |
| `ImageDescription`   | Struct describing the dimensions, format, and layout of a texture image.         |
| `OmrTextureCombiner` | Class for combining multiple PBR source images into a single OMR texture.        |
| `PitchCalculator`    | Static utility for computing row pitch, slice pitch, and mipmap level counts.    |
| `TextureCreator`     | Static utility for creating GPU textures from CPU-side image data.               |

## Usage Examples

### Loading and Saving Images

```csharp
// Load an image from a file
Image? image = Image.Load("texture.png");

// Save the image to a different format
if (image != null)
{
    image.Save("texture.dds", ImageFileType.Dds);
}

Creating a GPU Texture

// Assume 'context' is a valid IContext instance
Image? image = Image.Load("texture.png");
if (image != null)
{
    using (image)
    {
        TextureResource texture = TextureCreator.CreateTexture(context, image, generateMipmaps: true, "MyTexture");
    }
}

Creating a GPU Texture Asynchronously

// Assume 'context' is a valid IContext instance
Image? image = Image.Load("texture.png");
if (image != null)
{
    using (image)
    {
        var (result, texture, uploadHandle) = TextureCreator.CreateTextureAsyncWithResource(context, image, generateMipmaps: true, "MyTexture");
        if (result == ResultCode.Ok)
        {
            // Use texture and await uploadHandle if needed
        }
    }
}

Combining Textures

var combiner = new OmrTextureCombiner()
    .WithOcclusion("occlusion.png", ChannelComponent.R)
    .WithMetallic("metallic.png", ChannelComponent.G)
    .WithRoughnessFromGloss("gloss.png", ChannelComponent.B);

Image combinedImage = combiner.Combine();
combinedImage.Save("combined_omr.png", ImageFileType.Png);

Architecture Notes

• Design Patterns: The package uses a fluent builder pattern for the OmrTextureCombiner to facilitate easy configuration of texture channels.
• Dependencies: It relies on the HelixToolkit.Nex.Graphics package for GPU texture creation and management.
• Integration: The package is designed to work within the HelixToolkit-Nex engine's ECS architecture, allowing for efficient texture management and rendering.
• Performance: Utilizes GPU-based operations for efficient texture processing, including mipmap generation and texture uploads.

Build Configurations

The project now supports additional build configurations for Linux:

• LinuxDebug
• LinuxRelease

These configurations allow for building and testing the package on Linux environments, expanding the versatility and deployment options for developers using the HelixToolkit-Nex engine.