dolphin/Data/Sys/Shaders/AutoHDR.glsl

64 lines
1.6 KiB
GLSL

// Based on https://github.com/Filoppi/PumboAutoHDR
/*
[configuration]
[OptionRangeFloat]
GUIName = HDR Display Max Nits
OptionName = HDR_DISPLAY_MAX_NITS
MinValue = 80
MaxValue = 2000
StepAmount = 1
DefaultValue = 400
[OptionRangeFloat]
GUIName = Shoulder Start Alpha
OptionName = AUTO_HDR_SHOULDER_START_ALPHA
MinValue = 0
MaxValue = 1
StepAmount = 0.01
DefaultValue = 0
[OptionRangeFloat]
GUIName = Shoulder Pow
OptionName = AUTO_HDR_SHOULDER_POW
MinValue = 1
MaxValue = 10
StepAmount = 0.05
DefaultValue = 2.5
[/configuration]
*/
void main()
{
float4 color = Sample();
// Nothing to do here, we are in SDR
if (!OptionEnabled(hdr_output) || !OptionEnabled(linear_space_output))
{
SetOutput(color);
return;
}
const float hdr_paper_white = hdr_paper_white_nits / hdr_sdr_white_nits;
// Restore the original SDR (0-1) brightness (we might or might not restore it later)
color.rgb /= hdr_paper_white;
// Find the color average
float sdr_ratio = (color.r + color.g + color.b) / 3.0;
const float auto_hdr_max_white = max(HDR_DISPLAY_MAX_NITS / (hdr_paper_white_nits / hdr_sdr_white_nits), hdr_sdr_white_nits) / hdr_sdr_white_nits;
if (sdr_ratio > AUTO_HDR_SHOULDER_START_ALPHA && AUTO_HDR_SHOULDER_START_ALPHA < 1.0)
{
const float auto_hdr_shoulder_ratio = 1.0 - (max(1.0 - sdr_ratio, 0.0) / (1.0 - AUTO_HDR_SHOULDER_START_ALPHA));
const float auto_hdr_extra_ratio = pow(auto_hdr_shoulder_ratio, AUTO_HDR_SHOULDER_POW) * (auto_hdr_max_white - 1.0);
const float auto_hdr_total_ratio = sdr_ratio + auto_hdr_extra_ratio;
color.rgb *= auto_hdr_total_ratio / sdr_ratio;
}
color.rgb *= hdr_paper_white;
SetOutput(color);
}