计算着色器Open GL ES的多个输入

Question

我想创建一个程序，在Open GL ES.中获取多个矢量并返回一个矢量

我用这个例子编写了自己的代码。

如果我有以下代码：

static const char COMPUTE_SHADER[] =
"#version 310 esn"
"layout(local_size_x = 128) in;n"
"layout(std430) buffer;n"
"layout(binding = 0) buffer Output {n"
"uint elements[];n"
"} output_data;n"
"void main()n"
"{n"
"    uint ident = gl_GlobalInvocationID.x;n"
"output_data.elements[ident] = output_data.elements[ident] * "
"output_data.elements[ident];n"
"}";
...
GLuint data_buffer;
glGenBuffers(1, &data_buffer);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, data_buffer);
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 0, data_buffer);
glBufferData(GL_SHADER_STORAGE_BUFFER, sizeof(GLuint) * 10, (void*)data,
GL_DYNAMIC_READ);
GLuint program = glCreateProgram();
GLuint shader = LoadShader(COMPUTE_SHADER);
glAttachShader(program, shader);
glLinkProgram(program);
glUseProgram(program);
glDispatchCompute(10, 1, 1);
std::vector<uint32_t> ready_data(10);
GLuint* ptr = (GLuint*)glMapBufferRange(GL_SHADER_STORAGE_BUFFER, 0,
sizeof(GLuint) * 10, GL_MAP_READ_BIT);
std::copy(ptr, ptr + 10, ready_data.begin());
glUnmapBuffer(GL_SHADER_STORAGE_BUFFER);

它工作得非常好，并将我需要的所有内容存储在输出向量中。

但是接下来我想以这个例子为例，进行单独的输入和输出。它不起作用：

static const char COMPUTE_SHADER[] =
"   #version 310 es"
"layout(local_size_x = 128) in;"
"layout(std430) buffer;"
"layout(binding = 0) buffer Output {"
"    uint elements[];"
"} output_data;"
"layout(binding = 1) buffer Input0 {"
"    uint elements[];"
"} input_data0;"
"layout(binding = 2) readonly buffer Input1 {"
"uint elements[];"
"} input_data1;"
"void main()"
"{"
"    uint ident = gl_GlobalInvocationID.x;"
"    output_data.elements[ident] = input_data0.elements[ident] * input_data1.elements[ident];"
"}";
uint32_t data1[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
uint32_t data2[10] = {10, 20, 30, 40, 50, 60, 70, 80, 90, 100};
uint32_t data3[10] = {11, 21, 31, 41, 51, 61, 71, 81, 91, 101};
glGenBuffers(1, &input_buffer1);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, input_buffer1);
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 1, input_buffer1);
glBufferData(GL_SHADER_STORAGE_BUFFER, sizeof(GLuint) * 10, (void*)data2,
GL_STREAM_COPY);
glGenBuffers(1, &input_buffer2);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, input_buffer2);
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 2, input_buffer2);
glBufferData(GL_SHADER_STORAGE_BUFFER, sizeof(GLuint) * 10, (void*)data3,
GL_STREAM_COPY);
glGenBuffers(1, &data_buffer);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, data_buffer);
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 0, data_buffer);
glBufferData(GL_SHADER_STORAGE_BUFFER, sizeof(GLuint) * 10, (void*)data1,
GL_DYNAMIC_READ);
GLuint program = glCreateProgram();
GLuint shader = LoadShader(COMPUTE_SHADER);
glAttachShader(program, shader);
glLinkProgram(program);
glUseProgram(program);
glDispatchCompute(10, 1, 1);
GLuint* ptr = (GLuint*)glMapBufferRange(GL_SHADER_STORAGE_BUFFER, 0,
sizeof(GLuint) * 10, GL_MAP_READ_BIT);
std::copy(ptr, ptr + 10, ready_data.begin());
glUnmapBuffer(GL_SHADER_STORAGE_BUFFER);

它只输出数字1 2 3 .. 10，而我期望它们按元素相乘。

Answer 1

由于缺少换行符，第二个计算着色器甚至没有编译。

计算着色器的前2行

static const char COMPUTE_SHADER[] =
"   #version 310 es"
"layout(local_size_x = 128) in;"
.....

导致

#version 310 eslayout(local_size_x = 128) in;

在第一行末尾添加新行以解决问题：

static const char COMPUTE_SHADER[] =
"#version 310 esn"
"layout(local_size_x = 128) in;"
..... 

---

但我建议使用原始字符串文字(C++11(：

static const char COMPUTE_SHADER[] = R"(
#version 310 es
layout(local_size_x = 128) in;
layout(std430) buffer;
layout(binding = 0) buffer Output {
uint elements[];
} output_data;
layout(binding = 1) buffer Input0 {
uint elements[];
} input_data0;
layout(binding = 2) readonly buffer Input1 {
uint elements[];
} input_data1;
void main()
{
uint ident = gl_GlobalInvocationID.x;
output_data.elements[ident] = input_data0.elements[ident] * input_data1.elements[ident];
}
)";