// ReSharper disable once ParameterOnlyUsedForPreconditionCheck.Local
private static void AssertStep(PathStepDefinition step)
{
if (step == null)
{
throw new ArgumentNullException(nameof(step));
}
if (step.X > 255)
{
throw new ConversionException("Velocity X cannot be larger than 255");
}
if (step.Y > 255)
{
throw new ConversionException("Velocity X cannot be larger than 255");
}
}
public void SplitsIntoFrames()
{
var input = new PathStepDefinition[]
{
new PathStepDefinition {
F = 10, X = 4, Y = 4
},
};
var result = _transformer.TransformPath(input);
var expected = Enumerable.Range(0, 10)
.Select(_ => new OutputPathStepInfo {
FrameCount = 1, VelocityX = 4, VelocityY = 4
});
CollectionAssert.AreEqual(expected.ToStringCollection(), result.ToStringCollection());
}
public void LeavesJumpsAlone()
{
var input = new PathStepDefinition[]
{
new PathStepDefinition {
F = 2, X = 4, Y = 4
},
new PathStepDefinition {
F = 0, X = 0, Y = 0, Instruction = PathInstructionDefinition.Jump, Label = "Vel"
},
new PathStepDefinition {
F = 2, X = 4, Y = 4
},
};
var result = _transformer.TransformPath(input);
var expected = new List <OutputPathStepInfo>
{
new OutputPathStepInfo {
FrameCount = 1, VelocityX = 4, VelocityY = 4
},
new OutputPathStepInfo {
FrameCount = 1, VelocityX = 4, VelocityY = 4
},
new OutputPathStepInfo {
FrameCount = 0, VelocityX = 0, VelocityY = 0, Instruction = PathInstructionDefinition.Jump, Label = "Vel"
},
new OutputPathStepInfo {
FrameCount = 1, VelocityX = 4, VelocityY = 4
},
new OutputPathStepInfo {
FrameCount = 1, VelocityX = 4, VelocityY = 4
}
};
CollectionAssert.AreEqual(expected.ToStringCollection(), result.ToStringCollection());
}
// returns an unoptimized list of step infos
public IEnumerable <OutputPathStepInfo> TransformPath(IEnumerable <PathStepDefinition> steps)
{
PathStepDefinition previousStep = null; //new PathStepDefinition {X = 0, Y=-0};
PathStepDefinition currentStep = null;
foreach (var nextStep in steps.Concat(new List <PathStepDefinition>
{
new PathStepDefinition {
X = 0, Y = 0, Instruction = PathInstructionDefinition.End
}
}))
{
if (currentStep == null)
{
currentStep = nextStep;
previousStep = new PathStepDefinition {
X = 0, Y = 0
};
}
else
{
if (currentStep.Instruction == PathInstructionDefinition.Delta)
{
var labelEmitted = string.IsNullOrWhiteSpace(currentStep.Label);
AssertStep(currentStep);
for (int t = 0; t < currentStep.F; t++)
{
// Linear blending
var inMix = -(t - currentStep.In + 0.5) / currentStep.In;
var outMix = (t + 0.5 - (currentStep.F - currentStep.Out)) / currentStep.Out;
inMix = Math.Max(inMix, 0);
outMix = Math.Max(outMix, 0);
var curMix = 1 - inMix - outMix;
yield return(new OutputPathStepInfo
{
FrameCount = 1,
VelocityX = DoubleToShort(
((currentStep.X * curMix + previousStep.X * inMix + nextStep.X * outMix) /
(inMix + outMix + curMix))),
VelocityY = DoubleToShort(
((currentStep.Y * curMix + previousStep.Y * inMix + nextStep.Y * outMix) /
(inMix + outMix + curMix))),
Label = labelEmitted ? null : currentStep.Label,
});
labelEmitted = true;
}
}
else
{
yield return(new OutputPathStepInfo
{
Label = currentStep.Label,
Instruction = currentStep.Instruction,
VelocityX = (short)currentStep.X,
VelocityY = (short)currentStep.Y,
});
}
previousStep = currentStep;
currentStep = nextStep;
}
}
}
