std::shared_ptr<SpectraCalculator> SpectraGetDefaultGPUFourierTransf(
SpectraSharedObjects& shared_objects, std::size_t spectrum_size) {
std::size_t frame_size = spectrum_size * 2 - 1;
shared_objects.GLCanvas()->SetCurrent(*shared_objects.GLContext());
assert(spectrum_size > 2);
return std::make_shared<SpectraDefaultGPUMatrixTransf>(
shared_objects,
frame_size,
spectrum_size,
"Discrete Complex Fourier Transform (GPU)",
SpectraFourierMatrixGen(frame_size, spectrum_size));
}
SpectraDefaultGPUMatrixTransf::SpectraDefaultGPUMatrixTransf(
SpectraSharedObjects& shared_objects,
std::size_t in_sz,
std::size_t out_sz,
const std::string& transf_name,
const std::function<
std::complex<double>(
std::size_t,
std::size_t,
std::size_t,
std::size_t
)
>& gen
): gl_context(shared_objects.GLContext())
, gl_canvas(shared_objects.GLCanvas())
, max_transforms(4)
, current_transform(0)
, in_size(in_sz)
, out_size(out_sz)
, name(transf_name)
, transf_prog(shared_objects.BuildProgramWithXFB("xfb_matrix_transf.prog", "Output"))
, prog_input_offs(transf_prog, "InputOffs")
, prog_input_size(transf_prog, "InputSize")
, prog_input_data(transf_prog, "InputData")
, prog_matrix_data(transf_prog, "MatrixData")
, output_bufs(max_transforms)
, xfbs(max_transforms)
, queries(max_transforms)
{
assert(gl_context);
assert(gl_canvas);
std::vector<GLfloat> mat_data(in_size*out_size*2);
auto m = mat_data.begin();
for(std::size_t row=0; row!=out_size; ++row)
{
for(std::size_t col=0; col!=in_size; ++col)
{
std::complex<double> v = gen(col, row, in_size, out_size);
*m = GLfloat(v.real()); ++m;
*m = GLfloat(v.imag()); ++m;
}
}
assert(m == mat_data.end());
using namespace oglplus;
matrix_buf.Bind(Buffer::Target::Texture);
Buffer::Data(Buffer::Target::Texture, mat_data);
Texture::Active(0);
matrix_tex.Bind(Texture::Target::Buffer);
Texture::Buffer(
Texture::Target::Buffer,
PixelDataInternalFormat::RG32F,
matrix_buf
);
std::vector<GLfloat> init_data(in_size*max_transforms, 0.0f);
input_buf.Bind(Buffer::Target::Texture);
Buffer::Data(Buffer::Target::Texture, init_data);
Texture::Active(1);
input_tex.Bind(Texture::Target::Buffer);
Texture::Buffer(
Texture::Target::Buffer,
PixelDataInternalFormat::R32F,
input_buf
);
init_data.resize(out_size, 0.0f);
vao.Bind();
init_buf.Bind(Buffer::Target::Array);
Buffer::Data(Buffer::Target::Array, init_data);
(transf_prog|"Initial").Setup<GLfloat>().Enable();
VertexArray::Unbind();
for(GLuint t=0; t!=max_transforms; ++t)
{
xfbs[t].Bind();
output_bufs[t].Bind(Buffer::Target::TransformFeedback);
Buffer::Data(
Buffer::Target::TransformFeedback,
init_data,
Buffer::Property::Usage::DynamicCopy
);
output_bufs[t].BindBase(
Buffer::IndexedTarget::TransformFeedback,
0
);
}
}
