README.md

cuFFT Module

1D/2D/3D Fast Fourier Transform with C2C, R2C, C2R execution modes.

Import: const cufft = @import("zcuda").cufft; Enable: -Dcufft=true

CufftPlan

fn plan1d(nx, fft_type, batch) !CufftPlan;         // Create 1D FFT plan
fn plan2d(nx, ny, fft_type) !CufftPlan;             // Create 2D FFT plan
fn plan3d(nx, ny, nz, fft_type) !CufftPlan;         // Create 3D FFT plan
fn planMany(rank, n, ..., fft_type, batch) !CufftPlan; // Advanced batched plan
fn deinit(self) void;                                // Destroy plan
fn getSize(self) !usize;                             // Query workspace size
fn setStream(self, stream) !void;                    // Set CUDA stream

Execution Functions

Method	Input → Output	Precision
execC2C(input, output, direction)	Complex → Complex	float
execZ2Z(input, output, direction)	Complex → Complex	double
execR2C(input, output)	Real → Complex	float
execC2R(input, output)	Complex → Real	float
execD2Z(input, output)	Real → Complex	double
execZ2D(input, output)	Complex → Real	double

Enums

const FftType = enum {
    c2c_f32,  // Complex-to-complex (float)
    c2c_f64,  // Complex-to-complex (double)
    r2c_f32,  // Real-to-complex (float)
    c2r_f32,  // Complex-to-real (float)
    r2c_f64,  // Real-to-complex (double)
    c2r_f64,  // Complex-to-real (double)
};

const Direction = enum { forward, inverse };

Example

const cuda = @import("zcuda");

// 1D FFT: 1024-point forward C2C
const plan = try cuda.cufft.CufftPlan.plan1d(1024, .c2c_f32, 1);
defer plan.deinit();

try plan.setStream(stream);
try plan.execC2C(input_dev, output_dev, .forward);

// 2D FFT: 256×256
const plan_2d = try cuda.cufft.CufftPlan.plan2d(256, 256, .c2c_f32);
defer plan_2d.deinit();
try plan_2d.execC2C(input_dev, output_dev, .forward);