Files
SpineViewer/SpineViewer/Utilities/SFMLShader.cs
2025-04-09 01:07:17 +08:00

81 lines
3.0 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace SpineViewer.Utilities
{
public static class SFMLShader
{
/// <summary>
/// 用于非预乘纹理的 fragment shader, 乘上了插值后的透明度用于实现透明度变化(插值预乘), 并且输出预乘后的像素值
/// </summary>
private const string FRAGMENT_VertexAlpha =
"uniform sampler2D t;" +
"void main() { vec4 p = texture(t, gl_TexCoord[0].xy);" +
"p.rgb *= p.a * gl_Color.a;" +
"gl_FragColor = gl_Color * p; }"
;
/// <summary>
/// 用于预乘纹理的 fragment shader, 乘上了插值后的透明度用于实现透明度变化(插值预乘)
/// </summary>
private const string FRAGMENT_VertexAlphaPma =
"uniform sampler2D t;" +
"void main() { vec4 p = texture(t, gl_TexCoord[0].xy);" +
"p.rgb *= gl_Color.a;" +
"gl_FragColor = gl_Color * p; }"
;
/// <summary>
/// 预乘转非预乘 fragment shader
/// </summary>
private const string FRAGMENT_InvPma =
"uniform sampler2D t;" +
"void main() { vec4 p = texture(t, gl_TexCoord[0].xy);" +
"if (p.a > 0) p.rgb /= max(max(max(p.r, p.g), p.b), p.a);" +
"gl_FragColor = p; }"
;
/// <summary>
/// 考虑了顶点透明度变化的着色器, 输入是非预乘纹理像素, 输出是预乘像素
/// </summary>
private static SFML.Graphics.Shader? VertexAlpha = null;
/// <summary>
/// 考虑了顶点透明度变化的着色器, 输入和输出均是预乘像素值
/// </summary>
private static SFML.Graphics.Shader? VertexAlphaPma = null;
/// <summary>
/// 反预乘着色器, 用于得到正确透明度的非预乘画面
/// </summary>
public static SFML.Graphics.Shader? InversePma { get; private set; }
/// <summary>
/// 加载 Shader, 可能会存在异常导致着色器加载失败
/// </summary>
/// <exception cref="SFML.LoadingFailedException"></exception>
public static void Init()
{
VertexAlpha = SFML.Graphics.Shader.FromString(null, null, FRAGMENT_VertexAlpha);
VertexAlphaPma = SFML.Graphics.Shader.FromString(null, null, FRAGMENT_VertexAlphaPma);
InversePma = SFML.Graphics.Shader.FromString(null, null, FRAGMENT_InvPma);
}
/// <summary>
/// 获取绘制 Spine 的着色器
/// </summary>
/// <param name="pma">纹理是否是预乘的</param>
/// <param name="twoColor">是否是双色着色的(TODO)</param>
public static SFML.Graphics.Shader? GetSpineShader(bool pma, bool twoColor = false)
{
if (pma)
return VertexAlphaPma;
else
return VertexAlpha;
}
}
}