Ah, I didn't read the deranged code enough to spot the mutated unbias a few lines below.
It seems like the author has conflated unbiasing the input texture (which should always be done) with application of track/album gain.
Below should be an accurate rendition, in which I removed the double-work and removed the *1.8 factor in the RG computation I couldn't derive from anything.
Texture1D tex : WAVEFORMDATA;
SamplerState sTex
{
Filter = MIN_MAG_MIP_LINEAR;
AddressU = Clamp;
};
struct VS_IN
{
float2 pos : POSITION;
float2 tc : TEXCOORD0;
};
struct PS_IN
{
float4 pos : SV_POSITION;
float2 tc : TEXCOORD0;
};
float4 backgroundColor : BACKGROUNDCOLOR;
float4 highlightColor : HIGHLIGHTCOLOR;
float4 selectionColor : SELECTIONCOLOR;
float4 textColor : TEXTCOLOR;
float cursorPos : CURSORPOSITION;
bool cursorVisible : CURSORVISIBLE;
float seekPos : SEEKPOSITION;
bool seeking : SEEKING;
float4 replayGain : REPLAYGAIN; // album gain, track gain, album peak, track peak
float2 viewportSize : VIEWPORTSIZE;
bool horizontal : ORIENTATION;
bool shade_played : SHADEPLAYED;
PS_IN VS( VS_IN input )
{
PS_IN output = (PS_IN)0;
float2 half_pixel = float2(1,-1) / viewportSize;
output.pos = float4(input.pos - half_pixel, 0, 1);
if (horizontal)
output.tc = float2((input.tc.x + 1.0) / 2.0, input.tc.y);
else
output.tc = float2((-input.tc.y + 1.0) / 2.0, input.tc.x);
return output;
}
float4 bar( float pos, float2 tc, float4 fg, float4 bg, float width, bool show )
{
float dist = abs(pos - tc.x);
float4 c = (show && dist < width)
? lerp(fg, bg, smoothstep(0, width, dist))
: bg;
return c;
}
float4 evaluate(float4 bg, float4 fg, float factor)
{
return saturate(lerp(bg, fg, factor));
}
float4 played( float pos, float2 tc, float4 bg, float factor)
{
float4 c = bg;
if (pos > tc.x)
{
c = evaluate(backgroundColor, highlightColor, factor);
}
return c;
}
float RMSfactor( float2 tc, float border )
{
// alpha 1 indicates biased texture
float4 minmaxrms = tex.Sample(sTex, tc.x);
minmaxrms.rgb -= 0.5 * minmaxrms.a;
minmaxrms.rgb *= 1.0 + minmaxrms.a;
if (replayGain.g != -1000) {
minmaxrms.rgb *= pow(10,(replayGain.g) / 20); //use track gain
} else if (replayGain.r != -1000) {
minmaxrms.rgb *= pow(10,(replayGain.r) / 20); //use album gain
}
float belowWave = tc.y + border - minmaxrms.r;
float aboveWave = tc.y - border - minmaxrms.g;
float factorWave = min(abs(belowWave), abs(aboveWave));
bool insideWave = (belowWave > 0 && aboveWave < 0);
float diffRms = abs(tc.y) - border - minmaxrms.b;
float factorRms = abs(diffRms);
bool insideRms = diffRms < 0;
float factor = insideRms ? (1.0 - 0.5 * saturate(factorRms / border / 2)): 1.0;
factor = insideWave ? (factor * saturate(factorWave / border / 2)) : 0.0;
return factor;
}
float4 PS( PS_IN input ) : SV_Target
{
float dx, dy;
if (horizontal)
{
dx = 1/viewportSize.x;
dy = 1/viewportSize.y;
}
else
{
dx = 1/viewportSize.y;
dy = 1/viewportSize.x;
}
float seekWidth = 2.5 * dx;
float positionWidth = 2.5 * dx;
float factor = RMSfactor(input.tc, 2.5 * dy);
float4 c0 = evaluate(backgroundColor, textColor, factor);
if (shade_played)
c0 = played(cursorPos, input.tc, c0, factor);
c0 = bar(cursorPos, input.tc, selectionColor, c0, positionWidth, cursorVisible);
c0 = bar(seekPos, input.tc, selectionColor, c0, seekWidth, seeking );
return c0;
}
technique Render9
{
pass
{
VertexShader = compile vs_2_0 VS();
PixelShader = compile ps_2_0 PS();
}
}
Topic: foo_wave_seekbar (Read 811698 times)
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