Translate Shadertoy to Metal.

TODO: collapasable, copyable, download, etc

What Can you reliably automatically translate shadertoy shaders to iOS metal shard era?Converting Shadertoy shaders to iOS Metal shaders isn't a straightforward automatic process, but it's definitely doable with some manual adjustments. Here's a breakdown of what needs to be considered:

1. Language Differences: Shadertoy shaders are written in GLSL (OpenGL Shading Language), while Metal shaders use the Metal Shading Language (MSL). These languages have similar concepts but different syntax and some different built-in functions.

2. Coordinate Systems: Shadertoy shaders generally assume the origin (0,0) is at the bottom left of the screen, typical of OpenGL. Metal, like most other graphics systems on iOS, assumes the origin is at the top left. You will need to adjust coordinate systems in your shaders.

3. Texture Handling: Shadertoy shaders often use textures heavily, and how textures are sampled might differ in Metal. You’ll need to ensure that texture coordinates and sampling methods are translated correctly.

4. Time and Interaction: Shadertoy shaders often depend on global variables like iTime for animations or iMouse for interaction, which are automatically provided by the Shadertoy environment. In Metal, you'll need to manually pass these values from your iOS application to the shaders.

5. API and Environment Setup: Metal has a different API setup compared to WebGL (which Shadertoy is based on). You will need to set up a Metal pipeline, handle buffer creation, texture uploads, and more, which are typically handled more transparently in WebGL.

Steps for Conversion:

1. Translate GLSL to MSL: Start by translating the shader code from GLSL to MSL. Pay attention to syntactical differences, and replace built-in GLSL functions with their MSL equivalents.

2. Adjust for iOS Coordinates: Modify any coordinate-based calculations in the shader to reflect Metal’s coordinate system.

3. Setup Metal Pipeline: Write the necessary Objective-C or Swift code to compile the MSL shaders, create a Metal pipeline, and handle rendering. This includes creating buffers, textures, and handling any input like time or mouse position.

4. Test and Iterate: Run the shader on your iOS device, check for performance and visual accuracy, and adjust as necessary.

This process involves a fair bit of manual tweaking, especially in translating shader logic and ensuring that performance optimizations specific to iOS and Metal are in place. If you're consistently working with shaders, you might consider developing a more automated toolchain that can handle some of the repetitive aspects of this conversion.

Translate Shadertoy to Metal. created at Tue Jan 20 1970 20:38:39 GMT+0000 (Coordinated Universal Time)