43 lines
990 B
Markdown
43 lines
990 B
Markdown
# Chapter 22: Integrating SpriteKit & SceneKit
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As I read this book, I summarize what I think is wrong. If you think my comments are wrong then please let me know. We can dicuss more and update your opinion.
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## The fwidth function
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fwidth() is equivalent to:
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```
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abs(dfdx(p)) + abs(dfdy(p))
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```
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The camera position is defined by the constant value in the fragment shader. It's not good because the camera position can be changed.
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In Shaders.metal, in shipFragment(), replace:
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```
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float3 v = normalize(float3(0, 0, 10)); // camera position
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```
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With:
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```
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float3 v = normalize(cameraPosition);
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```
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Add the float3 as a parameter to the fragment function:
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```
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constant float3 &cameraPosition
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```
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In GameViewController.swift, in the conditional block where you set up the material, add this:
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```
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let cameraPosition = cameraNode.position
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material.setValue(cameraPosition, forKey: "cameraPosition")
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```
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step() generates a step function by comparing x to edge:
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