Question

我一直在尝试实现平铺延迟着色，现在我已经遇到问题一段时间了。我正在尝试存储一个由点光源组成的结构数组，我想要初始化并发送到计算着色器，我可以进一步处理它。我正在使用Shader存储缓冲区对象，我正在尝试使用glMapBufferRange来提供值。我添加了一些检查，以便如果数组大小为0，我会将屏幕涂成红色，如果它大于0则为黄色，到目前为止我似乎无法使其工作。

这是计算着色器：

#version 430
#define MAX_WORK_GROUP_SIZE 16
#define SCREEN_WIDTH 1280.0f
#define SCREEN_HEIGHT 720.0f


uniform sampler2D positionMap;
uniform sampler2D colorMap;
uniform sampler2D normalMap;
uniform sampler2D depthMap;

layout(binding = 4, rgba32f) uniform writeonly image2D finalImage;
layout(binding = 5, rgba32f) uniform writeonly image2D otherImage;

struct PointLight
{
    vec3 position; //4,8,12
    vec3 color; // 16,20, 24
    float radius; //28
    float diffuseIntensity; //32
    float ambientIntensity; //36
    float Constant; //40
    float Linear; //44
    float Exp; //48
};

layout(std430, binding = 6) buffer BufferObject
{
    PointLight pointLights[];
};

shared uint minDepth;
shared uint maxDepth;

layout(local_size_x = MAX_WORK_GROUP_SIZE, local_size_y = MAX_WORK_GROUP_SIZE)in;

void main()
{

    if(gl_LocalInvocationIndex == 0){
        minDepth = 0xFFFFFFFF;
        maxDepth = 0;
    }
    ivec2 pixelPos = ivec2(gl_GlobalInvocationID.xy);
    vec2 uv = vec2(pixelPos.x / SCREEN_WIDTH, pixelPos.y / SCREEN_HEIGHT);


    float d = texture(depthMap,uv).z;

    uint depth = uint(d * 0xFFFFFFFF);

    //compares the content of minDepth to depth and writes the minimum value to minDepth
    atomicMin(minDepth, depth);
//  barrier();
//compares the content of maxDepth to depth and writes the maximum value to the      maxDepth
    atomicMax(maxDepth, depth);



    ///Write a single texel into an image
/*  barrier();
    imageStore(finalImage, pixelPos, vec4(float(float(maxDepth) / float(0xFFFFFFFF))));

    barrier();
    imageStore(otherImage, pixelPos, vec4(float(float(minDepth) / float(0xFFFFFFFF))));
    */

    PointLight p = pointLights[0];
    PointLight p2 = pointLights[1];
    if(pointLights.length() == 0)
    {
        barrier();
        imageStore(finalImage, pixelPos, vec4(1.0,0.0,0.0,1.0));

        barrier();
        imageStore(otherImage, pixelPos, vec4(1.0,0.0,0.0,1.0));
    }
    if(pointLights.length() > 0)
    {
        barrier();
        imageStore(finalImage, pixelPos, vec4(1.0,1.0,0.0,1.0));

        barrier();
        imageStore(otherImage, pixelPos, vec4(1.0,1.0,0.0,1.0));
    }

}

以下是我尝试使用一些测试值来缓冲缓冲区的方法：

My3dVector currentColor(1.0f,1.0f,1.0f);
    glGenBuffers(1,&m_pointLightBuffer);
glBindBuffer(GL_SHADER_STORAGE_BUFFER,m_pointLightBuffer);
glBufferData(GL_SHADER_STORAGE_BUFFER,NUM_OF_LIGHTS*sizeof(struct TDPointLight), NULL, GL_STATIC_DRAW);

struct TDPointLight* pointlights = (struct TDPointLight*) glMapBufferRange(GL_SHADER_STORAGE_BUFFER, 0, NUM_OF_LIGHTS*sizeof(struct TDPointLight), GL_MAP_WRITE_BIT | GL_MAP_INVALIDATE_BUFFER_BIT );

int shit = ARRAY_SIZE_IN_ELEMENTS(pointlights);
for(int i = 0; i < NUM_OF_LIGHTS; ++i)
{
    float Max  = 80.0f;
    float Min = -80.0f;

    float MaxZ = 80.0f;
    float MinZ = -80.0f;

    float ranx = ((float(rand()) / float(RAND_MAX)) * (Max - Min)) + Min;
    float ranz = ((float(rand()) / float(RAND_MAX)) * (Max - Min)) + Min;

    int maxCol = 8;
    int minCol = 1;
    //int ranCol = ((rand() / RAND_MAX) * (maxCol - minCol)) + minCol;
    int ranCol = (rand()%(maxCol-minCol))+minCol;

    if(ranCol == 0)
        printf("error, color 8 doesnt exist");
    if(ranCol == 1)
        currentColor = COLOR_WHITE;
    if(ranCol == 2)
        currentColor = COLOR_RED;
    if(ranCol == 3)
        currentColor = COLOR_GREEN;
    if(ranCol == 4)
        currentColor = COLOR_CYAN;
    if(ranCol == 5)
        currentColor = COLOR_BLUE;
    if(ranCol == 6)
        currentColor = COLOR_PURPLE;
    if(ranCol == 7)
        currentColor = COLOR_ORANGE;
    if(ranCol == 8)
        printf("error, color 8 doesnt exist");

    pointlights[i].position = My3dVector(1.0f,1.0f,1.0f);
    pointlights[i].color = My3dVector(1.0f,0.0f,0.0f);
    pointlights[i].radius = 10.0f;
    pointlights[i].diffuseIntensity = 10.0f;
    pointlights[i].ambientIntensity = 0.1f;
    //pointlights[i].color = currentColor;
    //pointlights[i].position = My3dVector(ranx,3.0f,ranz);
    //m_pointLight[i].m_Position = My3dVector(0.0f,2.0f,0.0f);
    pointlights[i].Constant = 0.0f;
    pointlights[i].Linear = 0.0f;
    pointlights[i].Exp = 0.6f;
}
glUnmapBuffer(GL_SHADER_STORAGE_BUFFER);

然后这个过程就像：

使用计算着色器

设置所有制服，然后使用此代码绑定一些延迟纹理和其他东西

for(unsigned int i = 0; i<ARRAY_SIZE_IN_ELEMENTS(m_textures); ++i) 
{
    glActiveTexture(GL_TEXTURE0 + i);
glBindTexture(GL_TEXTURE_2D, m_textures[TDGBuffer_TEXTURE_TYPE_POSITION + i]);
}
glUniform1i(glGetUniformLocation(program,"depthMap"),3);
glActiveTexture(GL_TEXTURE3);
glBindTexture(GL_TEXTURE_2D,m_depthTexture);

//glActiveTexture(GL_TEXTURE4);
//glBindTexture(GL_TEXTURE_2D,m_finalTexture);
glBindImageTexture(4, m_finalTexture, 0, GL_FALSE, 0, GL_WRITE_ONLY, GL_RGBA32F);

glBindImageTexture(5,m_otherTexture,0,GL_FALSE,0,GL_WRITE_ONLY,GL_RGBA32F);
glBindBufferBase(GL_SHADER_STORAGE_BUFFER,6,m_pointLightBuffer);

然后最后在主循环中调用这些函数

glDispatchCompute((window_width/MAX_WORK_GROUP_SIZE), (window_height/MAX_WORK_GROUP_SIZE), 1);
glFinish();

它不能在代码中的任何地方使用任何内存屏障，但因为我没有在任何地方修改内容这不应该是一个问题，因为它只是初始化一次然后永远保持不变。

Answer 1

看来我刚犯了一个愚蠢的错误。重新排列结构以匹配vec4s的大小后，我可以使用

打印出正确的颜色和位置

PointLight p = pointLights[3];
PointLight p2 = pointLights[55];

//vec3 test = vec3(p.posX,p.posY,p.posZ);
//vec3 test2 = vec3(p2.posX,p2.posY,p2.posZ);
vec4 test = p.color;
vec4 test2 = p2.color;

barrier();
imageStore(finalImage, pixelPos, test);

barrier();
imageStore(otherImage, pixelPos, test2);

我的长度仍然是零，但我相信这是因为着色器不知道数组的大小已经更新

着色器存储缓冲区对象的长度为零，glMapBufferRange不起作用

1 个答案: