2014 snapchat source code
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 

37 lines
1.4 KiB

//
// SCNightModeEnhancementMetalModule.metal
// Snapchat
//
// Created by Chao Pang on 12/21/17.
//
//
#include <metal_stdlib>
using namespace metal;
typedef struct SampleBufferMetadata {
int iosSpeedRating;
float exposureTime;
float brightness;
}SampleBufferMetadata;
kernel void kernel_night_mode_enhancement(texture2d<float, access::read> sourceYTexture [[texture(0)]],
texture2d<float, access::read> sourceUVTexture [[texture(1)]],
texture2d<float, access::write> destinationYTexture [[texture(2)]],
texture2d<float, access::write> destinationUVTexture [[texture(3)]],
constant SampleBufferMetadata &metaData [[buffer(0)]],
uint2 gid [[thread_position_in_grid]],
uint2 size [[threads_per_grid]]) {
float valueY = sourceYTexture.read(gid).r;
float2 valueUV = sourceUVTexture.read(gid).rg;
float factor = 1.0 - metaData.brightness * 0.1;
factor = max(min(factor, 1.3), 1.0);
valueY = min(valueY * factor, 1.0);
valueUV.rg = max(min((valueUV.rg - 0.5) * factor + 0.5, 1.0), 0.0);
destinationYTexture.write(valueY, gid);
destinationUVTexture.write(float4(valueUV.r, valueUV.g, 0, 0), gid);
}