OpenGL GLSL 统一缓冲区对象

Question

I have a UBO, this is the code in the fragment shader.

layout (std140,binding = 5) uniform uAmbientLights
{
    vec4 position[10];
    vec4 color[10];
    vec4 intensity[10];
    vec4 radius[3];
};

my C++ code is like this. What my code does is create a buffer, vector containers that can hold up to 10 light data. I will set the position x/y, color & intensity x/y/z and a radius value. I used vec4 as I read that I needed to do padding.

    glCreateBuffers(1, &UBO);

    std::vector<float> pos(40);
    std::vector<float> clr(40);
    std::vector<float> intensity(40);
    std::vector<float> radius(12);

    glNamedBufferData(UBO, sizeof(float) * (pos.size() + clr.size() + intensity.size() + radius.size()), NULL, GL_DYNAMIC_DRAW);

    size_t posCount{}, clrCount{}, intensityCount{}, radiusCount{}, numOfAmbientLights{};

    for (eID curr : engine.GetSystem<sIdentifierSystem>().FindTaggedEntities(engine, "AMBIENTLIGHT"))
    {
        Transform& LTR = engine.GetComponent<Transform>(curr);
        Lighting& LL = engine.GetComponent<Lighting>(curr);

        pos[posCount++] = LTR.GetPosition().x;
        pos[posCount] = LTR.GetPosition().y;

        clr[clrCount++] = LL.getColor().x;
        clr[clrCount++] = LL.getColor().y;
        clr[clrCount] = LL.getColor().z;

        intensity[intensityCount++] = LL.getIntensity().x;
        intensity[intensityCount++] = LL.getIntensity().y;
        intensity[intensityCount] = LL.getIntensity().z;

        radius[radiusCount] = LL.getRadius();

        posCount += 3;
        clrCount += 2;
        intensityCount += 2;
        ++radiusCount;
        ++numOfAmbientLights;
    }

    glNamedBufferSubData(UBO, 0, sizeof(float) * pos.size(), &pos);
    glNamedBufferSubData(UBO, sizeof(float) * pos.size(), sizeof(float) * clr.size(), &clr);
    glNamedBufferSubData(UBO, sizeof(float) * pos.size() + sizeof(float) * clr.size(), sizeof(float) * intensity.size(), &intensity);
    glNamedBufferSubData(UBO, sizeof(float) * pos.size() + sizeof(float) * clr.size() + sizeof(float) * intensity.size(), sizeof(float) * radius.size(), &radius);

    glBindBufferBase(GL_UNIFORM_BUFFER, 5, UBO);

My values do not pass into the shader at all. Before using arrays for several lights, my code was working when it only contained 1 light data.

What am I doing wrong? I avoided vec3s & float, storing all my values with vec4 with value 0 to pad. I've checked that my vector container values are correct in-order.

My GL_MAX_UNIFORM_BLOCK_SIZE gives me 65k bytes whereas I only take (40+40+40+12)*4 = 528 bytes

Answer 1

My bad.. when updating the buffer, the 4 lines should instead be

    glNamedBufferSubData(UBO, 0, sizeof(float) * pos.size(), pos.data());
    glNamedBufferSubData(UBO, sizeof(float) * pos.size(), sizeof(float) * clr.size(), clr.data());
    glNamedBufferSubData(UBO, sizeof(float) * pos.size() + sizeof(float) * clr.size(), sizeof(float) * intensity.size(), intensity.data());
    glNamedBufferSubData(UBO, sizeof(float) * pos.size() + sizeof(float) * clr.size() + sizeof(float) * intensity.size(), sizeof(float) * radius.size(), radius.data());

I was passing the address to the vector instead of directly passing the vector data