Files
OpenRA/OpenRA.Game/Graphics/RgbaColorRenderer.cs
2024-07-29 21:56:36 +02:00

257 lines
8.6 KiB
C#

#region Copyright & License Information
/*
* Copyright (c) The OpenRA Developers and Contributors
* This file is part of OpenRA, which is free software. It is made
* available to you under the terms of the GNU General Public License
* as published by the Free Software Foundation, either version 3 of
* the License, or (at your option) any later version. For more
* information, see COPYING.
*/
#endregion
using System;
using System.Collections.Generic;
using System.Linq;
using OpenRA.Primitives;
namespace OpenRA.Graphics
{
public class RgbaColorRenderer
{
static readonly float3 Offset = new(0.5f, 0.5f, 0f);
readonly SpriteRenderer parent;
readonly Vertex[] vertices = new Vertex[4];
public RgbaColorRenderer(SpriteRenderer parent)
{
this.parent = parent;
}
public void DrawLine(in float3 start, in float3 end, float width, Color startColor, Color endColor, BlendMode blendMode = BlendMode.Alpha)
{
var delta = (end - start) / (end - start).XY.Length;
var corner = width / 2 * new float3(-delta.Y, delta.X, delta.Z);
startColor = Util.PremultiplyAlpha(startColor);
var sr = startColor.R / 255.0f;
var sg = startColor.G / 255.0f;
var sb = startColor.B / 255.0f;
var sa = startColor.A / 255.0f;
endColor = Util.PremultiplyAlpha(endColor);
var er = endColor.R / 255.0f;
var eg = endColor.G / 255.0f;
var eb = endColor.B / 255.0f;
var ea = endColor.A / 255.0f;
vertices[0] = new Vertex(start - corner + Offset, sr, sg, sb, sa, 0);
vertices[1] = new Vertex(start + corner + Offset, sr, sg, sb, sa, 0);
vertices[2] = new Vertex(end + corner + Offset, er, eg, eb, ea, 0);
vertices[3] = new Vertex(end - corner + Offset, er, eg, eb, ea, 0);
parent.DrawRGBAQuad(vertices, blendMode);
}
public void DrawLine(in float3 start, in float3 end, float width, Color color, BlendMode blendMode = BlendMode.Alpha)
{
var delta = (end - start) / (end - start).XY.Length;
var corner = width / 2 * new float2(-delta.Y, delta.X);
color = Util.PremultiplyAlpha(color);
var r = color.R / 255.0f;
var g = color.G / 255.0f;
var b = color.B / 255.0f;
var a = color.A / 255.0f;
vertices[0] = new Vertex(start - corner + Offset, r, g, b, a, 0);
vertices[1] = new Vertex(start + corner + Offset, r, g, b, a, 0);
vertices[2] = new Vertex(end + corner + Offset, r, g, b, a, 0);
vertices[3] = new Vertex(end - corner + Offset, r, g, b, a, 0);
parent.DrawRGBAQuad(vertices, blendMode);
}
/// <summary>
/// Calculate the 2D intersection of two lines.
/// Will behave badly if the lines are parallel.
/// Z position is the average of a and b (ignores actual intersection point if it exists).
/// </summary>
static float3 IntersectionOf(in float3 a, in float3 da, in float3 b, in float3 db)
{
var crossA = a.X * (a.Y + da.Y) - a.Y * (a.X + da.X);
var crossB = b.X * (b.Y + db.Y) - b.Y * (b.X + db.X);
var x = da.X * crossB - db.X * crossA;
var y = da.Y * crossB - db.Y * crossA;
var d = da.X * db.Y - da.Y * db.X;
return new float3(x / d, y / d, 0.5f * (a.Z + b.Z));
}
void DrawDisconnectedLine(IEnumerable<float3> points, float width, Color color, BlendMode blendMode)
{
using (var e = points.GetEnumerator())
{
if (!e.MoveNext())
return;
var lastPoint = e.Current;
while (e.MoveNext())
{
var point = e.Current;
DrawLine(lastPoint, point, width, color, blendMode);
lastPoint = point;
}
}
}
void DrawConnectedLine(float3[] points, float width, Color color, bool closed, BlendMode blendMode)
{
// Not a line
if (points.Length < 2)
return;
// Single segment
if (points.Length == 2)
{
DrawLine(points[0], points[1], width, color, blendMode);
return;
}
color = Util.PremultiplyAlpha(color);
var r = color.R / 255.0f;
var g = color.G / 255.0f;
var b = color.B / 255.0f;
var a = color.A / 255.0f;
var start = points[0];
var end = points[1];
var dir = (end - start) / (end - start).XY.Length;
var corner = width / 2 * new float3(-dir.Y, dir.X, dir.Z);
// Corners for start of line segment
var ca = start - corner;
var cb = start + corner;
// Segment is part of closed loop
if (closed)
{
var prev = points[^1];
var prevDir = (start - prev) / (start - prev).XY.Length;
var prevCorner = width / 2 * new float3(-prevDir.Y, prevDir.X, prevDir.Z);
ca = IntersectionOf(start - prevCorner, prevDir, start - corner, dir);
cb = IntersectionOf(start + prevCorner, prevDir, start + corner, dir);
}
var limit = closed ? points.Length : points.Length - 1;
for (var i = 0; i < limit; i++)
{
var next = points[(i + 2) % points.Length];
var nextDir = (next - end) / (next - end).XY.Length;
var nextCorner = width / 2 * new float3(-nextDir.Y, nextDir.X, nextDir.Z);
// Vertices for the corners joining start-end to end-next
var cc = closed || i < limit - 1 ? IntersectionOf(end + corner, dir, end + nextCorner, nextDir) : end + corner;
var cd = closed || i < limit - 1 ? IntersectionOf(end - corner, dir, end - nextCorner, nextDir) : end - corner;
// Fill segment
vertices[0] = new Vertex(ca + Offset, r, g, b, a, 0);
vertices[1] = new Vertex(cb + Offset, r, g, b, a, 0);
vertices[2] = new Vertex(cc + Offset, r, g, b, a, 0);
vertices[3] = new Vertex(cd + Offset, r, g, b, a, 0);
parent.DrawRGBAQuad(vertices, blendMode);
// Advance line segment
end = next;
dir = nextDir;
corner = nextCorner;
ca = cd;
cb = cc;
}
}
public void DrawLine(IEnumerable<float3> points, float width, Color color, bool connectSegments = false, BlendMode blendMode = BlendMode.Alpha)
{
if (!connectSegments)
DrawDisconnectedLine(points, width, color, blendMode);
else
DrawConnectedLine(points as float3[] ?? points.ToArray(), width, color, false, blendMode);
}
public void DrawPolygon(float3[] vertices, float width, Color color, BlendMode blendMode = BlendMode.Alpha)
{
DrawConnectedLine(vertices, width, color, true, blendMode);
}
public void DrawPolygon(float2[] vertices, float width, Color color, BlendMode blendMode = BlendMode.Alpha)
{
DrawConnectedLine(vertices.Select(v => new float3(v, 0)).ToArray(), width, color, true, blendMode);
}
public void DrawRect(in float3 tl, in float3 br, float width, Color color, BlendMode blendMode = BlendMode.Alpha)
{
var tr = new float3(br.X, tl.Y, tl.Z);
var bl = new float3(tl.X, br.Y, br.Z);
DrawPolygon(new[] { tl, tr, br, bl }, width, color, blendMode);
}
public void FillRect(in float3 tl, in float3 br, Color color, BlendMode blendMode = BlendMode.Alpha)
{
var tr = new float3(br.X, tl.Y, tl.Z);
var bl = new float3(tl.X, br.Y, br.Z);
FillRect(tl, tr, br, bl, color, blendMode);
}
public void FillRect(in float3 a, in float3 b, in float3 c, in float3 d, Color color, BlendMode blendMode = BlendMode.Alpha)
{
color = Util.PremultiplyAlpha(color);
var cr = color.R / 255.0f;
var cg = color.G / 255.0f;
var cb = color.B / 255.0f;
var ca = color.A / 255.0f;
vertices[0] = new Vertex(a + Offset, cr, cg, cb, ca, 0);
vertices[1] = new Vertex(b + Offset, cr, cg, cb, ca, 0);
vertices[2] = new Vertex(c + Offset, cr, cg, cb, ca, 0);
vertices[3] = new Vertex(d + Offset, cr, cg, cb, ca, 0);
parent.DrawRGBAQuad(vertices, blendMode);
}
public void FillRect(in float3 a, in float3 b, in float3 c, in float3 d,
Color topLeftColor, Color topRightColor, Color bottomRightColor, Color bottomLeftColor, BlendMode blendMode = BlendMode.Alpha)
{
vertices[0] = VertexWithColor(a + Offset, topLeftColor);
vertices[1] = VertexWithColor(b + Offset, topRightColor);
vertices[2] = VertexWithColor(c + Offset, bottomRightColor);
vertices[3] = VertexWithColor(d + Offset, bottomLeftColor);
parent.DrawRGBAQuad(vertices, blendMode);
}
static Vertex VertexWithColor(in float3 xyz, Color color)
{
color = Util.PremultiplyAlpha(color);
var cr = color.R / 255.0f;
var cg = color.G / 255.0f;
var cb = color.B / 255.0f;
var ca = color.A / 255.0f;
return new Vertex(xyz, cr, cg, cb, ca, 0);
}
public void FillEllipse(in float3 tl, in float3 br, Color color, BlendMode blendMode = BlendMode.Alpha)
{
// TODO: Create an ellipse polygon instead
var a = (br.X - tl.X) / 2;
var b = (br.Y - tl.Y) / 2;
var xc = (br.X + tl.X) / 2;
var yc = (br.Y + tl.Y) / 2;
for (var y = tl.Y; y <= br.Y; y++)
{
var z = float2.Lerp(tl.Z, br.Z, (y - tl.Y) / (br.Y - tl.Y));
var dx = a * (float)Math.Sqrt(1 - (y - yc) * (y - yc) / b / b);
DrawLine(new float3(xc - dx, y, z), new float3(xc + dx, y, z), 1, color, blendMode);
}
}
}
}