设置GL_TEXTURE_MAX_ANISOTROPY_EXT会导致下一帧崩溃

Question

我正在使用OpenGL 3.3和延迟着色.

当我在帧之间为我的采样器设置各向异性值时,下一帧会导致glClear下一帧的崩溃.

以下是我设置各向异性值的方法:

bool OpenGLRenderer::SetAnisotropicFiltering(const float newAnisoLevel)
{
    if (newAnisoLevel < 0.0f || newAnisoLevel > GetMaxAnisotropicFiltering())
        return false;

    mCurrentAnisotropy = newAnisoLevel;
    // the sampler used for geometry pass
    GLCALL(glSamplerParameterf(mTextureSampler, GL_TEXTURE_MAX_ANISOTROPY_EXT, mCurrentAnisotropy));
    // the sampler used in shading pass
    GLCALL(glSamplerParameterf(mGBuffer.mTextureSampler, GL_TEXTURE_MAX_ANISOTROPY_EXT, mCurrentAnisotropy));

    return true;
}

几何过程具有以下漫反射/普通纹理,并且设置如下:

    GLCALL(glUseProgram(mGeometryProgram.mProgramHandle));
    GLCALL(glGenSamplers(1, &mTextureSampler));
    GLCALL(glSamplerParameteri(mTextureSampler, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
    GLCALL(glSamplerParameteri(mTextureSampler, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR));
    GLCALL(glSamplerParameteri(mTextureSampler, GL_TEXTURE_WRAP_S, GL_REPEAT));
    GLCALL(glSamplerParameteri(mTextureSampler, GL_TEXTURE_WRAP_T, GL_REPEAT));
    GLCALL(glUniform1i(glGetUniformLocation(mGeometryProgram.mProgramHandle, "unifDiffuseTexture"), OpenGLTexture::TEXTURE_UNIT_DIFFUSE));
    GLCALL(glUniform1i(glGetUniformLocation(mGeometryProgram.mProgramHandle, "unifNormalTexture"), OpenGLTexture::TEXTURE_UNIT_NORMAL));
    GLCALL(glBindSampler(OpenGLTexture::TEXTURE_UNIT_DIFFUSE, mTextureSampler));
    GLCALL(glBindSampler(OpenGLTexture::TEXTURE_UNIT_NORMAL, mTextureSampler));
    GLCALL(glUseProgram(0));

着色过程具有以下用于照明计算的纹理:

    GLCALL(glUseProgram(shadingProgramID));
    GLCALL(glGenSamplers(1, &mTextureSampler));
    GLCALL(glSamplerParameteri(mTextureSampler, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
    GLCALL(glSamplerParameteri(mTextureSampler, GL_TEXTURE_MIN_FILTER, GL_LINEAR));
    GLCALL(glSamplerParameteri(mTextureSampler, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE));
    GLCALL(glSamplerParameteri(mTextureSampler, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE));
    GLCALL(glUniform1i(glGetUniformLocation(shadingProgramID, "unifPositionTexture"), GBuffer::GBUFFER_TEXTURE_POSITION));
    GLCALL(glUniform1i(glGetUniformLocation(shadingProgramID, "unifNormalTexture"), GBuffer::GBUFFER_TEXTURE_NORMAL));
    GLCALL(glUniform1i(glGetUniformLocation(shadingProgramID, "unifDiffuseTexture"), GBuffer::GBUFFER_TEXTURE_DIFFUSE));
    GLCALL(glBindSampler(GBuffer::GBUFFER_TEXTURE_POSITION, mTextureSampler));
    GLCALL(glBindSampler(GBuffer::GBUFFER_TEXTURE_NORMAL, mTextureSampler));
    GLCALL(glBindSampler(GBuffer::GBUFFER_TEXTURE_DIFFUSE, mTextureSampler));
    GLCALL(glUseProgram(0));

然后在下一帧上,当进行几何传递时,它会立即在glClear函数上崩溃

void OpenGLRenderer::GeometryPass(const RenderQueue& renderQueue)
{
    GLCALL(glUseProgram(mGeometryProgram.mProgramHandle));
    GLCALL(glBindFramebuffer(GL_DRAW_FRAMEBUFFER, mGBuffer.mFramebuffer));

    GLCALL(glDepthMask(GL_TRUE));
    GLCALL(glEnable(GL_DEPTH_TEST));

    // clear GBuffer fbo
    GLCALL(glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT));    // <----- crash!

    // both containers are assumed to be sorted by MeshID ascending
    auto meshIterator = mMeshes.begin();
    for (const Renderable& renderable : renderQueue)
    {
         // lots of draw code.....
    }

    GLCALL(glDisable(GL_DEPTH_TEST));
    GLCALL(glDepthMask(GL_FALSE));

    GLCALL(glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0));
    GLCALL(glUseProgram(0));
}

这可能是什么问题？

Answer 1

您的范围验证错误.各向异性的最小可接受值是1.0f.值1.0f(默认值)表示关闭(各向同性).

老实说,当你将各向异性设置在可接受的范围之上或之下时,我会考虑将值钳位到[1.0,MAX] ,而不是返回false而不做其他事情.稍后您可以通过检查mCurrentAnisotropy函数返回后的值来确定您的请求是不可接受的.如果将各向异性级别存储为配置文件中的选项并且硬件更改,则此选项非常有用.虽然16.0几乎普遍是这些天的最大值,但是一些非常旧的硬件仅支持8.0.您仍然可以返回false,报告警告或其他任何内容,但我个人总是将对各向异性水平的要求解释得太高以至于支持意味着:"我希望能够实现最高的各向异性."