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mirror of synced 2024-12-04 20:08:00 +01:00
Switch-Toolbox/Switch_Toolbox_Library/Rendering/PBRMapGenerator.cs

108 lines
4.0 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using GL_EditorFramework.Interfaces;
using GL_EditorFramework.GL_Core;
using OpenTK.Graphics.OpenGL;
using OpenTK;
namespace Switch_Toolbox.Library.Rendering
{
public class PBRMapGenerator
{
public int BrdfLUTMap = -1;
private ShaderProgram BrdfShader;
private int captureFBO = 1;
private int captureRBO = 1;
private bool IsBufferCreated()
{
return (captureFBO != -1 && captureRBO != -1);
}
private void GenerateFrameBuffer()
{
// setup framebuffer
GL.GenFramebuffers(1, out captureFBO);
GL.GenFramebuffers(1, out captureRBO);
}
public void GeneratImageBasedLightingMap()
{
// enable seamless cubemap sampling for lower mip levels in the pre-filter map.
GL.Enable(EnableCap.TextureCubeMapSeamless);
if (!IsBufferCreated())
GenerateFrameBuffer();
}
public void GenerateBrdfMap()
{
if (!IsBufferCreated())
GenerateFrameBuffer();
GL.UseProgram(BrdfShader.program);
GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
RenderQuad();
GL.BindFramebuffer(FramebufferTarget.Framebuffer, 0);
BrdfLUTMap = LoadBrdfLUTTexture();
GL.BindFramebuffer(FramebufferTarget.Framebuffer, captureFBO);
GL.BindRenderbuffer(RenderbufferTarget.Renderbuffer, captureRBO);
GL.RenderbufferStorage(RenderbufferTarget.Renderbuffer, RenderbufferStorage.DepthComponent24, 512, 512);
GL.FramebufferTexture2D(FramebufferTarget.Framebuffer, FramebufferAttachment.ColorAttachment0, TextureTarget.Texture2D, BrdfLUTMap, 0);
Matrix4 proj = Matrix4.Identity;
}
public static int LoadBrdfLUTTexture()
{
int texture;
GL.GenTextures(1, out texture);
GL.BindTexture(TextureTarget.Texture2D, texture);
GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rg32f, 512, 512, 0, OpenTK.Graphics.OpenGL.PixelFormat.Rg, PixelType.Float, (IntPtr)0);
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapS, (int)TextureWrapMode.ClampToEdge);
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapT, (int)TextureWrapMode.ClampToEdge);
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Linear);
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Linear);
return texture;
}
private static void RenderQuad()
{
int quadVAO = 0;
int quadVBO;
if (quadVAO == 0)
{
float[] vertices = {
// positions // texture Coords
-1.0f, 1.0f, 0.0f, 0.0f, 1.0f,
-1.0f, -1.0f, 0.0f, 0.0f, 0.0f,
1.0f, 1.0f, 0.0f, 1.0f, 1.0f,
1.0f, -1.0f, 0.0f, 1.0f, 0.0f,
};
GL.GenVertexArrays(1, out quadVAO);
GL.GenBuffers(1, out quadVBO);
GL.BindVertexArray(quadVAO);
GL.BindBuffer(BufferTarget.ArrayBuffer, quadVBO);
GL.BufferData(BufferTarget.ArrayBuffer, 4 * vertices.Length, vertices, BufferUsageHint.StaticDraw);
GL.EnableVertexAttribArray(0);
GL.VertexAttribPointer(0, 3, VertexAttribPointerType.Float, false, 5 * sizeof(float), (IntPtr)0);
GL.EnableVertexAttribArray(1);
GL.VertexAttribPointer(1, 2, VertexAttribPointerType.Float, false, 5 * sizeof(float), (IntPtr)(3 * sizeof(float)));
}
GL.BindVertexArray(quadVAO);
GL.DrawArrays(PrimitiveType.TriangleStrip, 0, 4);
GL.BindVertexArray(0);
}
}
}