我正在尝试生成一个frambuffer对象，并使用NDK（r5b）在本机Android应用程序中使用模板。目标设备正在运行froyo 2.2，支持OpenGL ES 2.0。
所以，我一直在我的 c++ 本机库中编写了很多 gl 代码，除了这个之外没有遇到任何问题。我似乎无法让它工作。
下面是用于创建帧缓冲的代码截图。完全性都很好，但屏幕仍然完全黑。这就像我正在创建的 fbo 并没有真正绑定到由应用程序的 Java 部分创建的 gl 表面。我的应用程序代码的其余部分都很好，如果我删除 fbo 创建和绑定，一切都很好，除了我没有我的应用程序所需的模板工作。
GLint backingWidth = 1024;
GLint backingHeight = 1024;
//Create the FrameBuffer and binds it
glGenFramebuffers(1, &_defaultFramebuffer);
checkGlError("glGenFramebuffers");
glBindFramebuffer(GL_FRAMEBUFFER, _defaultFramebuffer);
checkGlError("glBindFramebuffer");
//Create the RenderBuffer for offscreen rendering // Color
glGenRenderbuffers(1, &_colorRenderbuffer);
checkGlError("glGenRenderbuffers color");
glBindRenderbuffer(GL_RENDERBUFFER, _colorRenderbuffer);
checkGlError("glBindRenderbuffer color");
glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA4, backingWidth, backingHeight);
checkGlError("glRenderbufferStorage color");
//Create the RenderBuffer for offscreen rendering // Depth
glGenRenderbuffers(1, &_depthRenderbuffer);
checkGlError("glGenRenderbuffers depth");
glBindRenderbuffer(GL_RENDERBUFFER, _depthRenderbuffer);
checkGlError("glBindRenderbuffer depth");
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, backingWidth, backingHeight);
checkGlError("glRenderbufferStorage depth");
//Create the RenderBuffer for offscreen rendering // Stencil
glGenRenderbuffers(1, &_stencilRenderbuffer);
checkGlError("glGenRenderbuffers stencil");
glBindRenderbuffer(GL_RENDERBUFFER, _stencilRenderbuffer);
checkGlError("glBindRenderbuffer stencil");
glRenderbufferStorage(GL_RENDERBUFFER, GL_STENCIL_INDEX8, backingWidth, backingHeight);
checkGlError("glRenderbufferStorage stencil");
// bind renderbuffers to framebuffer object
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, _depthRenderbuffer);
checkGlError("glFramebufferRenderbuffer depth");
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, _colorRenderbuffer);
checkGlError("glFramebufferRenderbuffer color");
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, _stencilRenderbuffer);
checkGlError("glFramebufferRenderbuffer stencil");
//Test for FrameBuffer completeness
GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
checkGlError("glCheckFramebufferStatus");
switch (status)
{
case GL_FRAMEBUFFER_COMPLETE: LOGI("nnnFLIPBOOM : FBO complete GL_FRAMEBUFFER_COMPLETE %xnnn", status);break;
case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT: LOGI("nnnFLIPBOOM : FBO GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT %xnnn", status);break;
case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT: LOGI("nnnFLIPBOOM : FBO FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT %xnnn", status);break;
case GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS: LOGI("nnnFLIPBOOM : FBO FRAMEBUFFER_INCOMPLETE_DIMENSIONS %xnnn", status);break;
case GL_FRAMEBUFFER_UNSUPPORTED: LOGI("nnnFLIPBOOM : FBO GL_FRAMEBUFFER_UNSUPPORTED %xnnn", status);break;
default : LOGI("nnnFLIPBOOM : failed to make complete framebuffer object %xnnn", status);
}
我还尝试渲染为 2D 纹理而不是渲染缓冲区......也没用。
那么，有没有办法解决这个问题？我在这里弄错了什么吗？如果有人有任何想法，请告诉我....花了太多时间查找这个问题...呵呵;)
提前感谢！
干杯！
编辑：
好的，我已经设法使模板缓冲区工作，但 FBO 就是不工作。我认为 Android 并不完全支持 OpenGL ES 2.0（顺便说一句，在这里使用 r5b）。我认为方法存根已定义，但尚未完全实现。或者创建的GlSurfaceView无法与FBO正确链接。
至于模板缓冲区，我必须做
glEnable(GL_DEPTH_TEST);
并删除 glDepthMask 的使用，以便它们正常工作。
@
Zennichimaro，用于模板缓冲区的使用！
初始化期间：
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glEnable(GL_DEPTH_TEST);
在渲染过程中：
glViewport(0, 0, GetViewWidth(), GetViewHeight());
checkGlError("glViewport");
if (_firstRenderDone == false)
{
glClearDepthf( 0.9f );
glDepthMask( GL_TRUE );
glClear( GL_DEPTH_BUFFER_BIT );
glDepthMask( GL_FALSE );
_firstRenderDone = true;
}
glClearColor(M_channelToFloat(_backgroundColor.r),
M_channelToFloat(_backgroundColor.g),
M_channelToFloat(_backgroundColor.b),
M_channelToFloat(_backgroundColor.a));
checkGlError("glClearColor");
glClearStencil( 0 );
checkGlError("glClearStencil");
glClear( GL_COLOR_BUFFER_BIT | GL_STENCIL_BUFFER_BIT );
checkGlError("glClear");
_stencilLayer = 1;
//use our custom shaders
if( _program )
{
glUseProgram(_program);
if( transformMatrix3x3 != NULL )
{
glUniformMatrix3fv( _uniforms[OGL_UNIFORM_TRANSFORM], 1, false, transformMatrix3x3 );
}
// reset the shading.
glUniform1f( _uniforms[ OGL_UNIFORM_SHADE ], 0.0f );
}
//Do the actual drawing (Triangle Slip)
if( object )
{
_isRender = true;
object->OglDraw(this);
_isRender = false;
}
当我需要使用模板时，我会根据需要使用以下方法：
void GlEs2Renderer::StencilStartMask()
{
if (!USE_STENCIL) //For debugging purpose
return;
glEnable(GL_STENCIL_TEST);
//Turn off writing to the Color Buffer and Depth Buffer
//We want to draw to the Stencil Buffer only
glColorMask( GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE );
//Set 1 into the stencil buffer
glStencilFunc( GL_ALWAYS, NewStencilLayer(), 0xFFFFFFFF );
glStencilOp( GL_ZERO, GL_ZERO, GL_REPLACE );
}
void GlEs2Renderer::StencilUseMask()
{
if (!USE_STENCIL) //For debugging purpose
return;
//Turn back on Color Buffer and Depth Buffer
glColorMask( GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE );
//Only write to the Stencil Buffer where 1 is set
glStencilFunc( GL_EQUAL, StencilLayer(), 0xFFFFFFFF);
//Keep the content of the Stencil Buffer
glStencilOp( GL_KEEP, GL_KEEP, GL_KEEP );
}
void GlEs2Renderer::StencilOverlayMask()
{
if (!USE_STENCIL) //For debugging purpose
return;
//Turn back on Color Buffer and Depth Buffer
glColorMask( GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE );
glDepthMask(true);
//Only write to the Stencil Buffer where 1 is set
glStencilFunc( GL_EQUAL, StencilLayer(), 0xFFFFFFFF);
//Keep the content of the Stencil Buffer and increase when z passed
glStencilOp(GL_KEEP, GL_KEEP, GL_INCR);
}
最后，我做双通道技术在模板内绘制......下面是一个例子：
glVertexAttribPointer(OGL_ATTRIB_VERTEX, 2, GL_FLOAT, 0, 0, _triangles);
glEnableVertexAttribArray(OGL_ATTRIB_VERTEX);
glVertexAttribPointer(OGL_ATTRIB_COLOR, 4, GL_UNSIGNED_BYTE, 1, 0, _colors);
glEnableVertexAttribArray(OGL_ATTRIB_COLOR);
glContext->StencilStartMask();
glDrawArrays(GL_TRIANGLE_STRIP, 0, _nPoints);
glContext->StencilUseMask();;
glDrawArrays(GL_TRIANGLE_STRIP, 0, _nPoints);
glContext->StencilEndMask();
我的代码相当复杂，所以很难只发布与模板相关的内容，但我希望它能帮助;)