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TheRealMJP / Tex2DCatmullRom.hlsl
Last active October 26, 2024 14:55
An HLSL function for sampling a 2D texture with Catmull-Rom filtering, using 9 texture samples instead of 16
// The following code is licensed under the MIT license: https://gist.github.com/TheRealMJP/bc503b0b87b643d3505d41eab8b332ae
// Samples a texture with Catmull-Rom filtering, using 9 texture fetches instead of 16.
// See http://vec3.ca/bicubic-filtering-in-fewer-taps/ for more details
float4 SampleTextureCatmullRom(in Texture2D<float4> tex, in SamplerState linearSampler, in float2 uv, in float2 texSize)
{
// We're going to sample a a 4x4 grid of texels surrounding the target UV coordinate. We'll do this by rounding
// down the sample location to get the exact center of our "starting" texel. The starting texel will be at
// location [1, 1] in the grid, where [0, 0] is the top left corner.
float2 samplePos = uv * texSize;
#include <windows.h>
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <gl/gl.h>
#pragma comment(lib, "opengl32.lib")