OpenTK模版缓冲器

Question

我对opengl很陌生，我很难让模板缓冲区用于一个简单的例子；我有两种纹理，一种是位图，另一种是“掩码”，我试图用它隐藏一些部分，使其不受位图的影响。

我似乎无法做到这一点，当我试图在使用GL.TexImage2D创建模具纹理时设置模具格式时，我会得到一个无效的枚举，而当我试图为fbo附加一个模板扩展时，我会将我的面具画在：

GL.Enable(EnableCap.StencilTest);
GL.ClearStencil(0);
GL.StencilMask(0xFFFFFFFF); // read&write

// Create stencil texture
GL.GenTextures(1, out stencilTexture);
GL.BindTexture(TextureTarget.Texture2D, stencilTexture);
GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba8, stencilTextureWidth, stencilTextureHeight, 0, OpenTK.Graphics.OpenGL.PixelFormat.Rgba, PixelType.UnsignedByte, IntPtr.Zero);
//DOES NOT WORK: GL.TexImage2D(TextureTarget.Texture2D, 0, (PixelInternalFormat)All.StencilIndex, stencilTextureWidth, stencilTextureHeight, 0, OpenTK.Graphics.OpenGL.PixelFormat.StencilIndex, PixelType.UnsignedByte, IntPtr.Zero);

CREATE COLORTEXTURE FROM BITMAP

// Create a FBO and attach the stencil texture
GL.Ext.GenFramebuffers(1, out fbo);
GL.Ext.BindFramebuffer(FramebufferTarget.FramebufferExt, fbo);
GL.Ext.FramebufferTexture2D(FramebufferTarget.FramebufferExt, FramebufferAttachment.ColorAttachment0Ext, TextureTarget.Texture2D, stencilTexture, 0);
//DOES NOT WORK?: GL.Ext.FramebufferTexture2D(FramebufferTarget.FramebufferExt, FramebufferAttachment.StencilAttachmentExt, TextureTarget.Texture2D, stencilTexture, 0);

DRAW SOME STUFF INTO THE STENCILTEXTURE TO FUNCTION AS A MASK

GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.StencilBufferBit);

DRAW COLOR TEXTURE

GL.Enable(EnableCap.StencilTest);
GL.ClearStencil(0);
GL.ColorMask(false, false, false, false);
GL.StencilFunc(StencilFunction.Always, 1, 1);
GL.StencilOp(StencilOp.Keep, StencilOp.Keep, StencilOp.Replace);

DRAW THE STENCIL TEXTURE

GL.Disable(EnableCap.StencilTest);

我似乎找不到任何例子来证明这对于一个简单的2d案例(用纹理掩蔽纹理)。

编辑:这里更新的版本：http://pastebin.com/iuur2UTM

Answer 1

除非您实际将带模具的缓冲区附加到FBO，否则无法将模板操作呈现给FBO并期望它工作。FBO只有你给他们的缓冲区。

由于使用的是EXT版本的FBO，所以必须检查是否存在模版扩展。如果存在这种情况，那么您可以执行以下操作(注意:这是C。您必须将其转换为OpenTK和C#代码)：

GLuint renderBuffer;
glGenRenderbuffers(1, &renderBuffer);
glBindRenderbuffer(GL_RENDERBUFFER, renderBuffer);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8_EXT, stencilTextureWidth, stencilTextureHeight);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT_EXT, GL_RENDERBUFFER, renderBuffer);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT_EXT, GL_RENDERBUFFER, renderBuffer);

那会有帮助的。