wglShareLists失败，错误6：ERROR_INVALID_HANDLE句柄无效

Question

我尝试在两个类之间共享HPBUFFERARB：TGLForm和TGLForm2。 （我试过FBO，但有一个老的Borland Builder 6版本无法使用FBO进行管理）

我的目标是在两个openGL窗口中显示相同的缓冲区。

所以我的第一种形式之外声明此对象：

struct GLRenderToTexture 
{ 
struct 
{ 
    HDC   hdc; 
    HGLRC  hGlRc; 
    HPBUFFERARB hBuffer; 
    PFNWGLGETEXTENSIONSSTRINGARBPROC wglGetExtensionsStringARB; 
    PFNWGLCHOOSEPIXELFORMATARBPROC wglChoosePixelFormatARB; 
    PFNWGLCREATEPBUFFERARBPROC wglCreatePbufferARB; 
    PFNWGLGETPBUFFERDCARBPROC wglGetPbufferDCARB; 
    PFNWGLQUERYPBUFFERARBPROC wglQueryPbufferARB; 
    PFNWGLDESTROYPBUFFERARBPROC wglDestroyPbufferARB; 
    PFNWGLRELEASEPBUFFERDCARBPROC wglReleasePbufferDCARB; 
    PFNWGLBINDTEXIMAGEARBPROC wglBindTexImageARB; 
    PFNWGLRELEASETEXIMAGEARBPROC wglReleaseTexImageARB; 
} wgl; 
unsigned int texture; // the texture we're going to render to 
}; 

GLRenderToTexture RTT; 

我intialize它以具有相同的像素格式为第一GLForm：

void __fastcall TGLForm::FormCreate(TObject *Sender) 
{ 
    ghDC = GetDC(Handle); 
    if (!bSetupPixelFormat(ghDC)) Close(); 
    ghRC = wglCreateContext(ghDC); 
wglMakeCurrent(ghDC, ghRC); 
    InitializeGL(); 

    int  pixelFormats; 
    int  intAttrs[32] ={WGL_RED_BITS_ARB,8,WGL_GREEN_BITS_ARB,8,WGL_BLUE_BITS_ARB,8,WGL_ALPHA_BITS_ARB,8,WGL_DRAW_TO_PBUFFER_ARB, GL_TRUE,WGL_BIND_TO_TEXTURE_RGBA_ARB, GL_TRUE,WGL_SUPPORT_OPENGL_ARB,GL_TRUE,WGL_ACCELERATION_ARB,WGL_FULL_ACCELERATION_ARB,WGL_DOUBLE_BUFFER_ARB,GL_FALSE,0}; // 0 terminate the list 
    unsigned int numFormats = 0; 
    // get an acceptable pixel format to create the PBuffer with 
    if (RTT.wgl.wglChoosePixelFormatARB(ghDC, intAttrs, NULL, 1, &pixelFormats, &numFormats)==FALSE) 
     AnsiString error = AnsiString().sprintf("wglChoosePixelFormatARB returned %i", GetLastError()); // GetLastError will tell us why it failed 

    //Set some p-buffer attributes so that we can use this p-buffer as a 2d texture target 
    const int attributes[]= {WGL_TEXTURE_FORMAT_ARB, WGL_TEXTURE_RGBA_ARB, // p-buffer will have RBA texture format 
        WGL_TEXTURE_TARGET_ARB, WGL_TEXTURE_2D_ARB, 0}; // Of texture target will be GL_TEXTURE_2D 
    // the size of the PBuffer must be the same size as the texture 
    RTT.wgl.hBuffer= RTT.wgl.wglCreatePbufferARB(ghDC, pixelFormats, ClientWidth, ClientHeight, attributes); 
    RTT.wgl.hdc= RTT.wgl.wglGetPbufferDCARB(RTT.wgl.hBuffer); 
    RTT.wgl.hGlRc= wglCreateContext(RTT.wgl.hdc); 

wglMakeCurrent(NULL,NULL); 
} 

这是我第一次drawScene函数：“PaintGL（）”绘图完美绘制在此表单上：

void TGLForm::DrawSceneForm1() 
{ 
wglMakeCurrent(ghDC, ghRC); 
      ClientWidth = 1920; 
      ClientHeight = 1080; 

    // create a texture to use as the backbuffer 
    glGenTextures(1, &RTT.texture); 
    glBindTexture(GL_TEXTURE_2D, RTT.texture); 
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); 
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); 
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); 
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); 
    // make sure this is the same color format as the screen 
    glTexImage2D(GL_TEXTURE_2D, 0, 4, ClientWidth, ClientHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL); 


    // switch to the texture context 
wglMakeCurrent(RTT.wgl.hdc, RTT.wgl.hGlRc); 
    glEnable(GL_TEXTURE_2D);    // Enable Texture Mapping 
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE,GL_MODULATE); 

    glClear(GL_DEPTH_BUFFER_BIT); 

    glMatrixMode(GL_PROJECTION); 
    glLoadIdentity(); 
    glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0); 

    glMatrixMode(GL_MODELVIEW); 
    glLoadIdentity(); 

    glClearColor(0,0,0,1); 
    glClear(GL_COLOR_BUFFER_BIT); 

    glDisable(GL_TEXTURE_2D); 


    // switch back to the screen context 
wglMakeCurrent(ghDC, ghRC); 
    wglShareLists(ghRC, RTT.wgl.hGlRc); 
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE,GL_MODULATE); 

    glClear(GL_DEPTH_BUFFER_BIT); 
    glViewport(0, 0, ClientWidth, ClientHeight); 

    glMatrixMode(GL_PROJECTION); 
    glLoadIdentity(); 
    glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0); 

    glMatrixMode(GL_MODELVIEW); 
    glLoadIdentity(); 


wglMakeCurrent(RTT.wgl.hdc, RTT.wgl.hGlRc); 
    glEnable(GL_TEXTURE_2D); 
     glBindTexture(GL_TEXTURE_2D, RTT.texture); 
     PaintGL(); 
    glDisable(GL_TEXTURE_2D); 


wglMakeCurrent(ghDC, ghRC); 
    glEnable(GL_TEXTURE_2D); 
    glBindTexture(GL_TEXTURE_2D, RTT.texture); 
    RTT.wgl.wglBindTexImageARB(RTT.wgl.hBuffer, WGL_FRONT_LEFT_ARB); 

    glBegin(GL_QUADS); 
     glColor4ub(255,255,255,255); 
     glTexCoord2f (0.0, 0.0); glVertex2f (-1.0, -1.0); 
     glTexCoord2f (1.0, 0.0); glVertex2f (1.0, -1.0); 
     glTexCoord2f (1.0, 1.0); glVertex2f (1.0, 1.0); 
     glTexCoord2f (0.0, 1.0); glVertex2f (-1.0, 1.0); 
    glEnd(); 

    RTT.wgl.wglReleaseTexImageARB(RTT.wgl.hBuffer, WGL_FRONT_LEFT_ARB); 
    glDisable(GL_TEXTURE_2D); 

glFlush(); 
SwapBuffers(ghDC); 

wglMakeCurrent(NULL,NULL); 
} 

而这里是我的s的Econd GLForm的drawScene函数：问题是，我只看到了彩色四但这QUAD没有纹理，或质地空：

void TGLForm2::DrawSceneForm2() 
{ 
wglMakeCurrent(ghDC2, ghRC2); 
    ClientWidth = 1920; 
    ClientHeight = 1080; 

    wglShareLists(RTT.wgl.hGlRc, ghRC2); 
    if (wglShareLists(RTT.wgl.hGlRc,ghRC2) == FALSE) 
     SCmsgError(AnsiString().sprintf("wglShareLists returned %i", GetLastError())); 

    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE,GL_MODULATE); //ARC 

    glClear(GL_DEPTH_BUFFER_BIT); 
    glViewport(0, 0, ClientWidth, ClientHeight); 

    glMatrixMode(GL_PROJECTION); 
    glLoadIdentity(); 
    glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0); 

    glMatrixMode(GL_MODELVIEW); 
    glLoadIdentity(); 

    glEnable(GL_TEXTURE_2D); 

    glBindTexture(GL_TEXTURE_2D, RTT.texture); 
    RTT.wgl.wglBindTexImageARB(RTT.wgl.hBuffer, WGL_FRONT_LEFT_ARB); 

    glBegin(GL_QUADS); 
     glColor4ub(200,200,200,200); 
     glTexCoord2f (0.0, 0.0); glVertex2f (-1.0, -1.0); 
     glTexCoord2f (1.0, 0.0); glVertex2f (1.0, -1.0); 
     glTexCoord2f (1.0, 1.0); glVertex2f (1.0, 1.0); 
     glTexCoord2f (0.0, 1.0); glVertex2f (-1.0, 1.0); 
    glEnd(); 

    RTT.wgl.wglReleaseTexImageARB(RTT.wgl.hBuffer, WGL_FRONT_LEFT_ARB); 
    glDisable(GL_TEXTURE_2D); 

    glFlush(); 
    SwapBuffers(ghDC); 
} 

=>我如何可以检查此纹理为空或不？

将其导出到位图并检查它？

=>此wglShareLists在DrawSceneForm2返回与GetLastError函数的错误：

错误6：ERROR_INVALID_HANDLE句柄无效。

=>有人看到这个wglShareList或我的代码有什么问题吗？

Answer 1

当调用wglShareLists时，上下文肯定不是是最新的。在做其他事情之前，先分享一下。共享上下文将共享以后创建的任何内容。最好的办法是创建所有需要在启动时共享的上下文。如果您使用WGL_ARB_create_context，那么您甚至可以在创建调用中以原子方式执行此操作。

如果因为某些原因（但是，为什么？）不能（因为？），那么首先需要wglMakeCurrent(0,0);（在代码中做相反的处理，在共享之前使上下文保持最新状态）。

Answer 2

我也有类似的问题，即：

wglShareLists返回0

GetLastError（）返回3221684311（0xc0070057）

事实证明，你不能做太多与hglrc2（第二个参数传递到wglShareLists ），然后再调用wglShareLists。在我的情况下，我创建了，并glUseProgram着色器，然后尝试wglShareLists导致上面显示的错误。将第二个RC的wglCreateContext（hDC）工作后，立即将wglShareLists移动。我能够在两种情况下分享纹理。