如何用bindless指定UBO绑定?

时间:2016-11-01 00:43:05

标签: c++ opengl graphics 3d opengl-4

我创建了2个简单的UBO,其中包含vec4 colorA&color和' s和colorB' s。我只使用std140使用不必要的复杂UBO创建/绑定过程获得黑屏。如何在使用glCreate时指定哪个索引并使这个混乱工作,以便我可以选择colorA或colorB?

//APP
glCreateBuffers(1, &testUBO);
glNamedBufferData(testUBO, sizeof(glm::vec4), 0, GL_DYNAMIC_DRAW);
glGetNamedBufferParameterui64vNV(testUBO, GL_BUFFER_GPU_ADDRESS_NV, &uboScene_64);
glMakeNamedBufferResidentNV(testUBO, GL_READ_ONLY);


glm::vec4 myVec4 = glm::vec4(0.f, 1.f, 0.f, 1.f); //add to structs.h
glNamedBufferSubData(testUBO, 0, sizeof(glm::vec4), &myVec4

//SHARED HEADER
typedef glm::vec4 vec4;

layout(std140, binding = 0) uniform sceneBuffer
{
    vec4 colorA;
};

layout(std140, binding = 1) uniform objectBuffer
{
    vec4 colorB;
};

//SHADER PROGRAM
void main()
{
    Ci = colorA;
    Ci = colorB;
}

1 个答案:

答案 0 :(得分:1)

鉴于此着色器:

//GLSL
layout(std140, binding = 0) uniform sceneBuffer
{
    vec4 colorA;
};

layout(std140, binding = 1) uniform objectBuffer
{
    vec4 colorB;
};

这个C ++缓冲区初始化代码:

//Create scene buffer.
glCreateBuffers(1, &sceneUbo);
glNamedBufferStorage(sceneUbo, sizeof(glm::vec4), 0, GL_DYNAMIC_STORAGE_BIT);

glm::vec4 myVec4 = glm::vec4(0.f, 1.f, 0.f, 1.f);
glNamedBufferSubData(sceneUbo, 0, sizeof(glm::vec4), &myVec4);

//Create object buffer
glCreateBuffers(1, &objectUbo);
glNamedBufferStorage(objectUbo, sizeof(glm::vec4), 0, GL_DYNAMIC_STORAGE_BIT);

glm::vec4 myVec4 = glm::vec4(0.f, 1.f, 0.f, 1.f);
glNamedBufferSubData(objectUbo, 0, sizeof(glm::vec4), &myVec4);

以下是NV_uniform_buffer_unified_memory"无约束"代码如下:

//Get addresses
GLuint64 sceneUboAddr;
glGetNamedBufferParameterui64vNV(sceneUbo, GL_BUFFER_GPU_ADDRESS_NV, &sceneUboAddr);
glMakeNamedBufferResidentNV(sceneUbo, GL_READ_ONLY);

GLuint64 objectUboAddr;
glGetNamedBufferParameterui64vNV(objectUbo, GL_BUFFER_GPU_ADDRESS_NV, &objectUboAddr);
glMakeNamedBufferResidentNV(objectUbo, GL_READ_ONLY);

//You have to call this to turn on bindless buffers.
glEnableClientState(UNIFORM_BUFFER_UNIFIED_NV);

//0 represents the scene UBO's `binding` from GLSL:
glBufferAddressRangeNV(UNIFORM_BUFFER_ADDRESS_NV, 0, sceneUboAddr, sizeof(glm::vec4));
//1 represents the object UBO's `binding` from GLSL:
glBufferAddressRangeNV(UNIFORM_BUFFER_ADDRESS_NV, 1, objectUboAddr, sizeof(glm::vec4));

请注意,此扩展程序实际上需要glEnable/DisableClientState,这是从核心配置文件删除的功能。因此,您需要使用兼容性配置文件来使用它。

并且只是为了证明非无约束的代码几乎不会很复杂",这里是:

//The first 0 represents the scene UBO's `binding` from GLSL:
glBindBufferRange(GL_UNIFORM_BUFFER, 0, sceneUbo, 0, sizeof(glm::vec4));
//1 represents the object UBO's `binding` from GLSL:
glBindBufferRange(GL_UNIFORM_BUFFER, 1, objectUbo, 0, sizeof(glm::vec4));