97 lines
3 KiB
Metal
97 lines
3 KiB
Metal
//
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// Shaders.metal
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// Terrain2
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//
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// Created by Eryn Wells on 11/3/18.
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// Copyright © 2018 Eryn Wells. All rights reserved.
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//
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// File for Metal kernel and shader functions
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#include <metal_stdlib>
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#include <simd/simd.h>
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// Including header shared between this Metal shader code and Swift/C code executing Metal API commands
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#import "ShaderTypes.h"
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using namespace metal;
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typedef struct {
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float3 position [[attribute(VertexAttributePosition)]];
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float3 normal [[attribute(VertexAttributeNormal)]];
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float2 texCoord [[attribute(VertexAttributeTexCoord)]];
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} Vertex;
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typedef struct {
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float4 position [[position]];
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float4 eyeCoords;
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float3 normal;
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float2 texCoord;
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} ColorInOut;
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#pragma mark - Geometry Shaders
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vertex ColorInOut vertexShader(Vertex in [[stage_in]],
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constant packed_float3 *faceNormals [[buffer(BufferIndexFaceNormals)]],
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constant Uniforms &uniforms [[buffer(BufferIndexUniforms)]],
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uint vid [[vertex_id]])
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{
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ColorInOut out;
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float4 vertexCoords = float4(in.position, 1.0);
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float4 eyeCoords = uniforms.modelViewMatrix * vertexCoords;
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out.position = uniforms.projectionMatrix * eyeCoords;
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out.eyeCoords = eyeCoords;
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// TODO: Use the face normal.
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out.normal = normalize(in.normal);
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out.texCoord = in.texCoord;
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return out;
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}
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fragment float4 fragmentShader(ColorInOut in [[stage_in]],
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constant Uniforms &uniforms [[buffer(BufferIndexUniforms)]])
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{
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float3 normal = normalize(uniforms.normalMatrix * in.normal);
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float3 lightDirection = normalize(float3(-8, 8, 1) - in.eyeCoords.xyz);
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float3 viewDirection = normalize(-in.eyeCoords.xyz);
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float3 reflection = -reflect(lightDirection, normal);
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float4 out;
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float lightDotNormal = dot(normal, lightDirection);
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if (lightDotNormal <= 0.0) {
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// No color contribution to this pixel.
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out = float4();
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} else {
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float3 color = 0.8 * lightDotNormal * float3(0.6);
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float reflectDotViewDirection = dot(reflection, viewDirection);
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if (reflectDotViewDirection > 0.0) {
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color += 0.4 * pow(reflectDotViewDirection, 10) * float3(0, 0, 1);
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}
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out = float4(color, 1);
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}
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return out;
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}
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#pragma mark - Normal Shaders
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vertex float4 normalVertexShader(constant packed_float3 *positions [[buffer(NormalBufferIndexPoints)]],
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constant packed_float3 *normals [[buffer(NormalBufferIndexNormals)]],
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constant Uniforms &uniforms [[buffer(NormalBufferIndexUniforms)]],
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uint instID [[instance_id]],
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uint vertID [[vertex_id]])
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{
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float3 v = positions[instID];
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if ( vertID == 1 )
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{
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v += 0.25 * normals[instID];
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}
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float4 out = uniforms.projectionMatrix * uniforms.modelViewMatrix * float4(v, 1);
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return out;
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}
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fragment half4 normalFragmentShader()
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{
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return half4(0, 1, 0, 1);
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}
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