更新：スーパーフォーミュラを使用して描画する方法に関する回答は最後にあります
SuperEllipseを使用して、このような角の丸い四角形を描画する必要があります。
どこでも簡単にプロットできるときに描画する:
しかし、できないHLSLでは、プロットするかピクセルではないかという条件に行き詰まりました:
HLSL コードは次のとおりです。
sampler2D input : register(s0);
/// <summary>Explain the purpose of this variable.</summary>
/// <minValue>0.0</minValue>
/// <maxValue>10.0</maxValue>
/// <defaultValue>4.0</defaultValue>
float N : register(C1);
static const float pi = 3.1415926535f;
float2 superEllipse(float n, float a, float b, float theta)
{
float ct = cos(theta);
float st = sin(theta);
float x = a * sign(ct) * pow(abs(ct), 2.0f / n);
float y = b * sign(st) * pow(abs(st), 2.0f / n);
return float2(x, y);
}
float4 main(float2 uv : TEXCOORD) : COLOR
{
float2 uv1 = uv * float2(2.0f, 2.0f) - float2(1.0f, 1.0f);
float angle = degrees(atan2(uv1.y, uv1.x)) + 180.0f;
float tMax = pi * 2.0f;
float theta = 1.0f / 360.0f * angle * tMax;
float2 se = superEllipse(N, 1, 1, theta);
float angle1 = degrees(atan2(se.y, se.x)) + 180.0f;
float2 zero = float2(0.0f, 0.0f);
float dist1 = distance(se, zero);
float dist2 = distance(uv1, zero);
float4 color = float4(0, 0, 0, 1);
if(dist2 <= dist1)
color += float4(0, 1, 0, 1);
return color;
}
エラーは「dist1」および「dist2」変数にあるようです。
(シャザムで作成)
動作する C# コードは次のとおりです。
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void Run()
{
const double halfPi = Math.PI*2.0d;
double nValue = trackBar1.Value/10.0d;
double aValue = trackBar2.Value/100.0d;
double bValue = trackBar3.Value/100.0d;
label1.Text = nValue.ToString("F2");
label2.Text = aValue.ToString("F2");
label3.Text = bValue.ToString("F2");
double n = nValue;
double a = aValue;
double b = bValue;
// Build list of points
const int points = 100;
const double step = 360.0d/points;
var list = new List<PointF>();
for (int i = 0; i <= points; i++)
{
double angle = step*i;
double t = 1.0d/360.0d*angle;
double theta = t*halfPi;
double x;
double y;
SuperEllipse.Evaluate(n, a, b, theta, out x, out y);
list.Add(new PointF((float) x, (float) y));
}
/* Drawing */
// Scale and center
for (int index = 0; index < list.Count; index++)
{
PointF pointF = list[index];
pointF.X++;
pointF.Y++;
pointF.X *= (pictureBox1.Width - 10)/2f;
pointF.Y *= (pictureBox1.Height - 10)/2f;
pointF.X += 5;
pointF.Y += 5;
list[index] = pointF;
}
// Draw and show
var bitmap = new Bitmap(pictureBox1.Width, pictureBox1.Height);
using (Graphics graphics = Graphics.FromImage(bitmap))
{
//graphics.TranslateTransform(1, 1);
graphics.DrawLines(Pens.Red, list.ToArray());
// graphics.FillClosedCurve(Brushes.Red, fs, FillMode.Alternate);
}
if (pictureBox1.Image != null)
{
pictureBox1.Image.Dispose();
}
pictureBox1.Image = bitmap;
}
private void trackBar1_Scroll(object sender, EventArgs e)
{
Run();
}
private void trackBar2_Scroll(object sender, EventArgs e)
{
Run();
}
private void trackBar3_Scroll(object sender, EventArgs e)
{
Run();
}
}
public static class SuperEllipse
{
public static void Evaluate(double n, double a, double b, double theta, out double x, out double y)
{
double cost = Math.Cos(theta);
double sint = Math.Sin(theta);
x = a*Math.Sign(cost)*Math.Pow(Math.Abs(cost), 2.0d/n);
y = b*Math.Sign(sint)*Math.Pow(Math.Abs(sint), 2.0d/n);
}
}
}
アップデート
HLSL の SuperFormula (まだ正しくない)
sampler2D input : register(s0);
/// <summary>Explain the purpose of this variable.</summary>
/// <minValue>0.0</minValue>
/// <maxValue>8.0</maxValue>
/// <defaultValue>1.0</defaultValue>
float A : register(C0);
/// <summary>Explain the purpose of this variable.</summary>
/// <minValue>0.0</minValue>
/// <maxValue>8.0</maxValue>
/// <defaultValue>1.0</defaultValue>
float B : register(C1);
/// <summary>Explain the purpose of this variable.</summary>
/// <minValue>0.0</minValue>
/// <maxValue>8.0</maxValue>
/// <defaultValue>1.0</defaultValue>
float M : register(C2);
/// <summary>Explain the purpose of this variable.</summary>
/// <minValue>0.0, 0.0, 0.0</minValue>
/// <maxValue>8.0, 8.0, 8.0</maxValue>
/// <defaultValue>1.0, 1.0, 1.0</defaultValue>
float3 N : register(C3);
float4 main(float2 uv : TEXCOORD) : COLOR
{
float2 uv1 = uv * float2(2.0f, 2.0f) - float2(1.0f, 1.0f);
float angle = degrees(atan2(uv1.y, uv1.x)) + 180.0f;
float mt = M * angle / 4.0f;
float magnitude = pow((pow((cos(mt) / A), N.y) + pow((sin(mt) / B), N.z)), -(1.0f / N.x));
float2 zero = float2(0.0f, 0.0f);
float dist1 = distance(uv1, zero);
float4 color = float4(0, 0, 0, 1);
if(dist1 <= magnitude)
color += float4(dist1, 1, 0, 1);
return color;
}
最後に、Kevin のおかげでSuperformulaを使用した角丸四角形:
sampler2D input : register(s0);
/// <summary>Explain the purpose of this variable.</summary>
/// <minValue>0.0</minValue>
/// <maxValue>8.0</maxValue>
/// <defaultValue>1.0</defaultValue>
float A : register(C0);
/// <summary>Explain the purpose of this variable.</summary>
/// <minValue>0.0</minValue>
/// <maxValue>8.0</maxValue>
/// <defaultValue>1.0</defaultValue>
float B : register(C1);
/// <summary>Explain the purpose of this variable.</summary>
/// <minValue>0.0</minValue>
/// <maxValue>8.0</maxValue>
/// <defaultValue>8.0</defaultValue>
float M : register(C2);
/// <summary>Explain the purpose of this variable.</summary>
/// <minValue>0.0, 0.0, 0.0</minValue>
/// <maxValue>8.0, 8.0, 8.0</maxValue>
/// <defaultValue>1.0, 1.0, 1.0</defaultValue>
float3 N : register(C3);
float4 main(float2 uv : TEXCOORD) : COLOR
{
float2 uv1 = uv * float2(2.0f, 2.0f) - float2(1.0f, 1.0f);
float angle = atan2(uv1.y, uv1.x);
float mt = M * angle / 4.0f;
float magnitude = pow((pow((abs(cos(mt)) / A), N.y) + pow((abs(sin(mt)) / B), N.z)), -(1.0f / N.x));
float2 zero = float2(0.0f, 0.0f);
float dist1 = distance(uv1, zero);
float4 color = float4(0, 0, 0, 1);
float alpha = 1.0f / magnitude * dist1;
if(dist1 <= magnitude)
color += float4(1, 0.5, 0, 1);
return color;
}
