Opengl 为什么glGetUniformBlockIndex（）返回无效的索引？

我在程序中使用以下顶点着色器，但出于某种原因，

glgetuniformblockdex（id，“draw2DQuadVS”）

返回

无效的索引

程序在使用前已正确链接，并且传递了正确的id。此外，未设置opengl错误。有什么解释吗

    #version 410
    uniform CBPostProcessVS
    {
        vec4  f4_Proj2DTo3D;
    } postProcessVS;

    uniform CBDraw2DQuadVS
    {
        vec4  f4_PositionOffsetAndScale;
        vec4  f4_TexcoordOffsetAndScale;
    } draw2DQuadVS;

        in vec3 vPosition;
    in vec2 vTexcoord0;
    in vec4 vColor0;
    in vec3 vTangent;
    in vec3 vBinormal;
    in vec3 vNormal;


    out vec2 v_vTexcoord0;
    out vec3 vPosFactor;


    void main()
    {    
        vec2 pos = (vec2(vPosition) * draw2DQuadVS.f4_PositionOffsetAndScale.zw) + vec2(draw2DQuadVS.f4_PositionOffsetAndScale);
        vec2 uv = (vec2(vTexcoord0) * draw2DQuadVS.f4_TexcoordOffsetAndScale.zw) + vec2(draw2DQuadVS.f4_TexcoordOffsetAndScale);

        gl_Position = vec4(pos,0,1);
        v_vTexcoord0 = uv;

        vPosFactor.xy = uv * vec2(postProcessVS.f4_Proj2DTo3D) + postProcessVS.f4_Proj2DTo3D.zw;
        vPosFactor.z = 1.0;
    }

draw2DQuadsVS
不是统一块的名称。块的名称为
CBDraw2DQuadVS
draw2DQuadsVS
只是块作用域的GLSL名称

有关更多信息，请访问

draw2DQuadsVS
不是统一块的名称。块的名称为
CBDraw2DQuadVS
draw2DQuadsVS
只是块作用域的GLSL名称

有关更多信息，请访问

glGetUniformBlockIndex(id, "draw2DQuadVS")