cnq3/code/renderer/hlsl/sprite.hlsl
myT 718b966414 depth fade fixes and improvements
- renamed r_softSprites to r_depthFade
  the term's more descriptive and it helps that UE4 uses it
- fixed the GL3 fragment shader halving the depth bias
- fixed the D3D11 pixel shader only fetching depth sample 0
  not fixed for GL3 yet, see the code comments for that
- added support for more blend states
- added the q3map_cnq3_depthFade general shader directive
2020-04-26 16:32:51 +02:00

119 lines
3.2 KiB
HLSL

/*
===========================================================================
Copyright (C) 2019 Gian 'myT' Schellenbaum
This file is part of Challenge Quake 3 (CNQ3).
Challenge Quake 3 is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.
Challenge Quake 3 is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Challenge Quake 3. If not, see <https://www.gnu.org/licenses/>.
===========================================================================
*/
// depth sprite vertex and pixel shaders
cbuffer VertexShaderBuffer
{
matrix modelViewMatrix;
matrix projectionMatrix;
float4 clipPlane;
};
struct VIn
{
float4 position : POSITION;
float4 color : COLOR0;
float2 texCoords : TEXCOORD0;
};
struct VOut
{
float4 position : SV_Position;
float4 color : COLOR0;
float2 texCoords : TEXCOORD0;
float2 proj2232 : TEXCOORD1;
float depthVS : DEPTHVS;
float clipDist : SV_ClipDistance0;
};
VOut vs_main(VIn input)
{
float4 positionVS = mul(modelViewMatrix, float4(input.position.xyz, 1));
VOut output;
output.position = mul(projectionMatrix, positionVS);
output.color = input.color;
output.texCoords = input.texCoords;
output.proj2232 = float2(-projectionMatrix[2][2], projectionMatrix[2][3]);
output.depthVS = -positionVS.z;
output.clipDist = dot(positionVS, clipPlane);
return output;
}
cbuffer PixelShaderBuffer
{
uint alphaTest;
float distance;
float offset;
float dummy;
float4 colorScale;
float4 colorBias;
};
Texture2D texture0 : register(t0);
SamplerState sampler0 : register(s0);
Texture2DMS<float2> textureDepth;
/*
f = far clip plane distance
n = near clip plane distance
exp = exponential depth value (as stored in the Z-buffer)
2 * f * n B
linear(exp) = ----------------------- = -------
(f + n) - exp * (f - n) exp - A
f + n -2 * f * n
with A = ----- and B = ----------
f - n f - n
*/
float LinearDepth(float zwDepth, float proj22, float proj32)
{
return proj32 / (zwDepth - proj22);
}
float Contrast(float d, float power)
{
bool aboveHalf = d > 0.5;
float base = saturate(2.0 * (aboveHalf ? (1.0 - d) : d));
float r = 0.5 * pow(base, power);
return aboveHalf ? (1.0 - r) : r;
}
float4 ps_main(VOut input, uint sampleIndex : SV_SampleIndex) : SV_TARGET
{
float4 r = input.color * texture0.Sample(sampler0, input.texCoords);
if((alphaTest == 1 && r.a == 0.0) ||
(alphaTest == 2 && r.a >= 0.5) ||
(alphaTest == 3 && r.a < 0.5))
discard;
float zwDepth = textureDepth.Load(input.position.xy, sampleIndex).x;
float depthS = LinearDepth(zwDepth, input.proj2232.x, input.proj2232.y);
float depthP = input.depthVS - offset;
float scale = Contrast((depthS - depthP) * distance, 2.0);
float4 r2 = lerp(r * colorScale + colorBias, r, scale);
return r2;
}