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More selection stuff. Do we really want to select tangent lines this way?

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This commit is contained in:
That_One_Nerd 2024-03-18 13:14:30 -04:00
parent 8618442bba
commit 55cb7af2ac
4 changed files with 85 additions and 21 deletions
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3
Base/Graphables/ColumnTable.cs
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@ -48,9 +48,6 @@ public class ColumnTable : Graphable
return items;
}
public override bool ShouldSelectGraphable(in GraphForm graph, Float2 graphMousePos, double factor) => false;
public override Float2 GetSelectedPoint(in GraphForm graph, Float2 graphMousePos) => default;
// Nothing to preload, everything is already cached.
public override void Preload(Float2 xRange, Float2 yRange, double step) { }
}

41
Base/Graphables/SlopeField.cs
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@ -74,9 +74,46 @@ public class SlopeField : Graphable
public override void EraseCache() => cache.Clear();
public override long GetCacheBytes() => cache.Count * 48;
public override bool ShouldSelectGraphable(in GraphForm graph, Float2 graphMousePos, double factor)
{
Float2 nearestPos = new(Math.Round(graphMousePos.x * detail) / detail,
Math.Round(graphMousePos.y * detail) / detail);
public override bool ShouldSelectGraphable(in GraphForm graph, Float2 graphMousePos, double factor) => false;
public override Float2 GetSelectedPoint(in GraphForm graph, Float2 graphMousePos) => default;
double epsilon = 1 / (detail * 2.0);
GraphLine line = GetFromCache(epsilon, nearestPos.x, nearestPos.y);
double slope = (line.b.y - line.a.y) / (line.b.x - line.a.x);
if (graphMousePos.x < Math.Min(line.a.x, line.b.x) ||
graphMousePos.x > Math.Max(line.a.x, line.b.x)) return false;
double allowedDist = factor * graph.DpiFloat * 10 / 192;
double lineX = graphMousePos.x,
lineY = slope * (lineX - nearestPos.x) + nearestPos.y;
Int2 pointScreen = graph.GraphSpaceToScreenSpace(new Float2(lineX, lineY));
Int2 mouseScreen = graph.GraphSpaceToScreenSpace(graphMousePos);
Int2 dist = new(pointScreen.x - mouseScreen.x,
pointScreen.y - mouseScreen.y);
double totalDist = Math.Sqrt(dist.x * dist.x + dist.y * dist.y);
return totalDist <= allowedDist;
}
public override Float2 GetSelectedPoint(in GraphForm graph, Float2 graphMousePos)
{
Float2 nearestPos = new(Math.Round(graphMousePos.x * detail) / detail,
Math.Round(graphMousePos.y * detail) / detail);
double epsilon = 1 / (detail * 2.0);
GraphLine line = GetFromCache(epsilon, nearestPos.x, nearestPos.y);
double slope = (line.b.y - line.a.y) / (line.b.x - line.a.x);
double lineX = graphMousePos.x,
lineY = slope * (lineX - nearestPos.x) + nearestPos.y;
Float2 point = new(lineX, lineY);
return point;
}
public override void Preload(Float2 xRange, Float2 yRange, double step)
{

58
Base/Graphables/TangentLine.cs
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@ -21,10 +21,12 @@ public class TangentLine : Graphable
protected readonly double length;
protected double currentSlope;
// X is slope, Y is height.
protected Float2 currentSlope;
// No binary search for this, I want it to be exact.
protected Dictionary<double, double> slopeCache;
// Value: X is slope, Y is height.
protected Dictionary<double, Float2> slopeCache;
public TangentLine(double length, double position, Equation parent)
{
@ -39,27 +41,28 @@ public class TangentLine : Graphable
public override IEnumerable<IGraphPart> GetItemsToRender(in GraphForm graph)
{
Float2 point = new(Position, parentEqu(Position));
return [MakeSlopeLine(point, currentSlope),
new GraphUiCircle(point, 8)];
Float2 point = new(Position, currentSlope.y);
return [MakeSlopeLine(), new GraphUiCircle(point, 8)];
}
protected GraphLine MakeSlopeLine(Float2 position, double slope)
protected GraphLine MakeSlopeLine()
{
double dirX = length, dirY = slope * length;
double dirX = length, dirY = currentSlope.x * length;
double magnitude = Math.Sqrt(dirX * dirX + dirY * dirY);
dirX /= magnitude * 2 / length;
dirY /= magnitude * 2 / length;
return new(new(position.x + dirX, position.y + dirY), new(position.x - dirX, position.y - dirY));
return new(new(Position + dirX, currentSlope.y + dirY), new(Position - dirX, currentSlope.y - dirY));
}
protected double DerivativeAtPoint(double x)
protected Float2 DerivativeAtPoint(double x)
{
// If value is already computed, return it.
if (slopeCache.TryGetValue(x, out double y)) return y;
if (slopeCache.TryGetValue(x, out Float2 val)) return val;
const double step = 1e-3;
double result = (parentEqu(x + step) - parentEqu(x)) / step;
double initial = parentEqu(x);
Float2 result = new((parentEqu(x + step) - initial) / step, initial);
slopeCache.Add(x, result);
return result;
}
@ -67,10 +70,37 @@ public class TangentLine : Graphable
public override Graphable DeepCopy() => new TangentLine(length, Position, parent);
public override void EraseCache() => slopeCache.Clear();
public override long GetCacheBytes() => slopeCache.Count * 16;
public override long GetCacheBytes() => slopeCache.Count * 24;
public override bool ShouldSelectGraphable(in GraphForm graph, Float2 graphMousePos, double factor) => false;
public override Float2 GetSelectedPoint(in GraphForm graph, Float2 graphMousePos) => default;
public override bool ShouldSelectGraphable(in GraphForm graph, Float2 graphMousePos, double factor)
{
GraphLine line = MakeSlopeLine();
if (graphMousePos.x < Math.Min(line.a.x - 0.25, line.b.x - 0.25) ||
graphMousePos.x > Math.Max(line.a.x + 0.25, line.b.x + 0.25)) return false;
double allowedDist = factor * graph.DpiFloat * 80 / 192;
double lineX = graphMousePos.x,
lineY = currentSlope.x * (lineX - Position) + currentSlope.y;
Int2 pointScreen = graph.GraphSpaceToScreenSpace(new Float2(lineX, lineY));
Int2 mouseScreen = graph.GraphSpaceToScreenSpace(graphMousePos);
Int2 dist = new(pointScreen.x - mouseScreen.x,
pointScreen.y - mouseScreen.y);
double totalDist = Math.Sqrt(dist.x * dist.x + dist.y * dist.y);
return totalDist <= allowedDist;
}
public override Float2 GetSelectedPoint(in GraphForm graph, Float2 graphMousePos)
{
GraphLine line = MakeSlopeLine();
double lineX = Math.Clamp(graphMousePos.x,
Math.Min(line.a.x, line.b.x),
Math.Max(line.a.x, line.b.x)),
lineY = currentSlope.x * (lineX - Position) + currentSlope.y;
return new Float2(lineX, lineY);
}
public override void Preload(Float2 xRange, Float2 yRange, double step)
{

4
Testing/Program.cs
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@ -14,8 +14,8 @@ internal static class Program
GraphForm graph = new("One Of The Graphing Calculators Of All Time");
Equation possibleA = new(x => Math.Sin(x));
SlopeField sf = new(2, (x, y) => Math.Cos(x));
Equation possibleA = new(x => x * x * x);
SlopeField sf = new(2, (x, y) => 1 / x);
TangentLine tl = new(2, 2, possibleA);
graph.Graph(possibleA, sf, tl);