mame/hlsl/prescale.fx
ImJezze 7add547602 Refactoring of render targes and vector texture coordinates
- implemented proper texture coordinates for vector quad primitive
- vector screen is now processed in texture coordinates
- revered workaround for raster screen, which is again processed in
texture coordinates
- known issue: cocktail mode for vector screen looks wrong
2016-03-12 16:03:28 +01:00

110 lines
3 KiB
HLSL

// license:BSD-3-Clause
// copyright-holders:Ryan Holtz,Themaister,ImJezze
//-----------------------------------------------------------------------------
// Pre-scale Effect
//
// Uses the hardware bilinear interpolator to avoid having to sample 4 times manually.
//
// https://github.com/libretro/common-shaders/blob/master/retro/shaders/sharp-bilinear.cg
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// Sampler Definitions
//-----------------------------------------------------------------------------
texture Diffuse;
sampler DiffuseSampler = sampler_state
{
Texture = <Diffuse>;
MipFilter = LINEAR;
MinFilter = LINEAR;
MagFilter = LINEAR;
AddressU = CLAMP;
AddressV = CLAMP;
AddressW = CLAMP;
};
//-----------------------------------------------------------------------------
// Vertex Definitions
//-----------------------------------------------------------------------------
struct VS_OUTPUT
{
float4 Position : POSITION;
float2 TexCoord : TEXCOORD0;
};
struct VS_INPUT
{
float4 Position : POSITION;
float4 Color : COLOR0;
float2 TexCoord : TEXCOORD0;
float2 Unused : TEXCOORD1;
};
struct PS_INPUT
{
float2 TexCoord : TEXCOORD0;
};
//-----------------------------------------------------------------------------
// Pre-scale Vertex Shader
//-----------------------------------------------------------------------------
uniform float2 ScreenDims;
uniform float2 TargetDims;
uniform float2 SourceDims;
VS_OUTPUT vs_main(VS_INPUT Input)
{
VS_OUTPUT Output = (VS_OUTPUT)0;
Output.Position = float4(Input.Position.xyz, 1.0f);
Output.Position.xy /= ScreenDims;
Output.Position.y = 1.0f - Output.Position.y; // flip y
Output.Position.xy -= 0.5f; // center
Output.Position.xy *= 2.0f; // zoom
Output.TexCoord = Input.TexCoord;
Output.TexCoord += 0.5f / TargetDims; // half texel offset correction (DX9)
return Output;
}
//-----------------------------------------------------------------------------
// Pre-scale Pixel Shader
//-----------------------------------------------------------------------------
float4 ps_main(PS_INPUT Input) : COLOR
{
float2 Scale = TargetDims / SourceDims;
float2 TexelDims = Input.TexCoord * SourceDims;
float2 i = floor(TexelDims);
float2 s = frac(TexelDims);
// Figure out where in the texel to sample to get the correct pre-scaled bilinear.
float2 CenterDistance = s - 0.5f;
float2 RegionRange = 0.5f - 0.5f / Scale;
float2 f = (CenterDistance - clamp(CenterDistance, -RegionRange, RegionRange)) * Scale + 0.5f;
float2 TexCoord = (i + f) / SourceDims;
return tex2D(DiffuseSampler, TexCoord);
}
//-----------------------------------------------------------------------------
// Pre-scale Technique
//-----------------------------------------------------------------------------
technique DefaultTechnique
{
pass Pass0
{
Lighting = FALSE;
VertexShader = compile vs_3_0 vs_main();
PixelShader = compile ps_3_0 ps_main();
}
}