private int CalculateBRDF(ShaderProg shader, int framebuffer, int renderbuffer, int size = 512)
{
int textureId = /*LoadBrdfImage("Resources/zB8UF1G.png");*/ AllocateBrdf(size);
Quad quad = new Quad();
GL.BindFramebuffer(FramebufferTarget.Framebuffer, framebuffer);
GL.BindRenderbuffer(RenderbufferTarget.Renderbuffer, renderbuffer);
GL.RenderbufferStorage(RenderbufferTarget.Renderbuffer,
RenderbufferStorage.DepthComponent24, size, size);
GL.FramebufferTexture2D(FramebufferTarget.Framebuffer,
FramebufferAttachment.ColorAttachment0,
TextureTarget.Texture2D,
textureId, 0);
ShaderProg brdfShader = shader;
GL.UseProgram(brdfShader.ProgramID);
brdfShader.EnableVertexAttribArrays();
GL.Viewport(0, 0, size, size);
GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
quad.RenderQuad();
GL.BindFramebuffer(FramebufferTarget.Framebuffer, 0);
brdfShader.DisableVertexAttribArrays();
return(textureId);
}
private int TransformHdrToPrefilteredCubemap(int textureId, ShaderProg shader, int framebuffer, int renderbuffer, int size = 128, uint mipnapLevels = 5)
{
Cube cube = new Cube();
GL.BindFramebuffer(FramebufferTarget.Framebuffer, framebuffer);
GL.FramebufferRenderbuffer(FramebufferTarget.Framebuffer, FramebufferAttachment.ColorAttachment0, RenderbufferTarget.Renderbuffer, renderbuffer);
int cubemap = AllocatePrefilterCubemap(size);
Matrix4 projection = Matrix4.Identity;
Matrix4[] views = new Matrix4[6];
GenerateMatricesForMapHdrToCubemap(ref projection, ref views);
ShaderProg prefilteredShader = shader;
GL.UseProgram(prefilteredShader.ProgramID);
prefilteredShader.EnableVertexAttribArrays();
GL.UniformMatrix4(prefilteredShader.GetUniform("projection"), false, ref projection);
UniformHelper helper = new UniformHelper();
bool suc;
suc = helper.TryAddUniformTextureCubemap(textureId, "environmentMap", prefilteredShader, TextureUnit.Texture0);
for (uint i = 0; i < mipnapLevels; ++i)
{
uint mipWidth = (uint)(size * Math.Pow(0.5f, i));
uint mipHeight = (uint)(size * Math.Pow(0.5f, i));
GL.BindRenderbuffer(RenderbufferTarget.Renderbuffer, renderbuffer);
GL.RenderbufferStorage(RenderbufferTarget.Renderbuffer, RenderbufferStorage.DepthComponent24, (int)mipWidth, (int)mipHeight);
GL.Viewport(0, 0, (int)mipWidth, (int)mipHeight);
float roughness = (float)i / (float)(mipnapLevels - 1);
helper.TryAddUniform1(roughness, "roughness", prefilteredShader);
GL.BindFramebuffer(FramebufferTarget.Framebuffer, framebuffer);
// GL.Disable(EnableCap.FramebufferSrgb);
//GL.ActiveTexture(TextureUnit.Texture0);
for (uint j = 0; j < 6; ++j)
{
GL.UniformMatrix4(prefilteredShader.GetUniform("view"), false, ref views[j]);
GL.FramebufferTexture2D(FramebufferTarget.Framebuffer, FramebufferAttachment.ColorAttachment0,
TextureTarget.TextureCubeMapPositiveX + (int)j, cubemap, (int)i);
GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
// GL.Enable(EnableCap.FramebufferSrgb);
cube.RenderCube(); // renders a 1x1 cube
// Console.WriteLine(GL.CheckNamedFramebufferStatus(framebuffer, FramebufferTarget.Framebuffer));
}
prefilteredShader.DisableVertexAttribArrays();
}
GL.BindFramebuffer(FramebufferTarget.Framebuffer, 0);
return(cubemap);
}
private int TransformHdrToCubemap(int textureId, string textureName, ShaderProg shader, int framebuffer, int renderbuffer, int size = 2048)
{
Cube cube = new Cube();
GL.BindFramebuffer(FramebufferTarget.Framebuffer, framebuffer);
GL.BindRenderbuffer(RenderbufferTarget.Renderbuffer, renderbuffer);
GL.RenderbufferStorage(RenderbufferTarget.Renderbuffer, RenderbufferStorage.DepthComponent24, size, size);
GL.FramebufferRenderbuffer(FramebufferTarget.Framebuffer, FramebufferAttachment.ColorAttachment0, RenderbufferTarget.Renderbuffer, renderbuffer);
int cubemap = AllocateCubemap(size);
Matrix4 projection = Matrix4.Identity;
Matrix4[] views = new Matrix4[6];
GenerateMatricesForMapHdrToCubemap(ref projection, ref views);
ShaderProg equirectangularToCubemapShader = shader;
GL.UseProgram(equirectangularToCubemapShader.ProgramID);
equirectangularToCubemapShader.EnableVertexAttribArrays();
GL.UniformMatrix4(equirectangularToCubemapShader.GetUniform("projection"), false, ref projection);
UniformHelper helper = new UniformHelper();
bool suc;
if (textureName == "equirectangularMap")
{
suc = helper.TryAddUniformTexture2D(textureId, textureName, equirectangularToCubemapShader, TextureUnit.Texture0);
}
else
{
suc = helper.TryAddUniformTextureCubemap(textureId, textureName, equirectangularToCubemapShader, TextureUnit.Texture0);
}
GL.Viewport(0, 0, size, size);
GL.BindFramebuffer(FramebufferTarget.Framebuffer, framebuffer);
GL.ActiveTexture(TextureUnit.Texture0);
for (int i = 0; i < 6; ++i)
{
GL.UniformMatrix4(equirectangularToCubemapShader.GetUniform("view"), false, ref views[i]);
GL.FramebufferTexture2D(FramebufferTarget.Framebuffer, FramebufferAttachment.ColorAttachment0,
TextureTarget.TextureCubeMapPositiveX + i, cubemap, 0);
GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
cube.RenderCube(); // renders a 1x1 cube
}
equirectangularToCubemapShader.DisableVertexAttribArrays();
GL.BindFramebuffer(FramebufferTarget.Framebuffer, 0);
return(cubemap);
}