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IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /////////////////////////////////////////////////////////////////////////////// #include #include // Round a / b to nearest higher integer value int cuda_iDivUp(int a, int b) { return (a + (b - 1)) / b; } // complex math functions __device__ float2 conjugate(float2 arg) { return make_float2(arg.x, -arg.y); } __device__ float2 complex_exp(float arg) { return make_float2(cosf(arg), sinf(arg)); } __device__ float2 complex_add(float2 a, float2 b) { return make_float2(a.x + b.x, a.y + b.y); } __device__ float2 complex_mult(float2 ab, float2 cd) { return make_float2(ab.x * cd.x - ab.y * cd.y, ab.x * cd.y + ab.y * cd.x); } // generate wave heightfield at time t based on initial heightfield and // dispersion relationship __global__ void generateSpectrumKernel(float2 *h0, float2 *ht, unsigned int in_width, unsigned int out_width, unsigned int out_height, float t, float patchSize) { unsigned int x = blockIdx.x * blockDim.x + threadIdx.x; unsigned int y = blockIdx.y * blockDim.y + threadIdx.y; unsigned int in_index = y * in_width + x; unsigned int in_mindex = (out_height - y) * in_width + (out_width - x); // mirrored unsigned int out_index = y * out_width + x; // calculate wave vector float2 k; k.x = (-(int)out_width / 2.0f + x) * (2.0f * CUDART_PI_F / patchSize); k.y = (-(int)out_width / 2.0f + y) * (2.0f * CUDART_PI_F / patchSize); // calculate dispersion w(k) float k_len = sqrtf(k.x * k.x + k.y * k.y); float w = sqrtf(9.81f * k_len); if ((x < out_width) && (y < out_height)) { float2 h0_k = h0[in_index]; float2 h0_mk = h0[in_mindex]; // output frequency-space complex values ht[out_index] = complex_add(complex_mult(h0_k, complex_exp(w * t)), complex_mult(conjugate(h0_mk), complex_exp(-w * t))); // ht[out_index] = h0_k; } } // update height map values based on output of FFT __global__ void updateHeightmapKernel(float *heightMap, float2 *ht, unsigned int width) { unsigned int x = blockIdx.x * blockDim.x + threadIdx.x; unsigned int y = blockIdx.y * blockDim.y + threadIdx.y; unsigned int i = y * width + x; // cos(pi * (m1 + m2)) float sign_correction = ((x + y) & 0x01) ? -1.0f : 1.0f; heightMap[i] = ht[i].x * sign_correction; } // update height map values based on output of FFT __global__ void updateHeightmapKernel_y(float *heightMap, float2 *ht, unsigned int width) { unsigned int x = blockIdx.x * blockDim.x + threadIdx.x; unsigned int y = blockIdx.y * blockDim.y + threadIdx.y; unsigned int i = y * width + x; // cos(pi * (m1 + m2)) float sign_correction = ((x + y) & 0x01) ? -1.0f : 1.0f; heightMap[i] = ht[i].y * sign_correction; } // generate slope by partial differences in spatial domain __global__ void calculateSlopeKernel(float *h, float2 *slopeOut, unsigned int width, unsigned int height) { unsigned int x = blockIdx.x * blockDim.x + threadIdx.x; unsigned int y = blockIdx.y * blockDim.y + threadIdx.y; unsigned int i = y * width + x; float2 slope = make_float2(0.0f, 0.0f); if ((x > 0) && (y > 0) && (x < width - 1) && (y < height - 1)) { slope.x = h[i + 1] - h[i - 1]; slope.y = h[i + width] - h[i - width]; } slopeOut[i] = slope; } // wrapper functions extern "C" void cudaGenerateSpectrumKernel(float2 *d_h0, float2 *d_ht, unsigned int in_width, unsigned int out_width, unsigned int out_height, float animTime, float patchSize) { dim3 block(8, 8, 1); dim3 grid(cuda_iDivUp(out_width, block.x), cuda_iDivUp(out_height, block.y), 1); generateSpectrumKernel<<>>(d_h0, d_ht, in_width, out_width, out_height, animTime, patchSize); } extern "C" void cudaUpdateHeightmapKernel(float *d_heightMap, float2 *d_ht, unsigned int width, unsigned int height, bool autoTest) { dim3 block(8, 8, 1); dim3 grid(cuda_iDivUp(width, block.x), cuda_iDivUp(height, block.y), 1); if (autoTest) { updateHeightmapKernel_y<<>>(d_heightMap, d_ht, width); } else { updateHeightmapKernel<<>>(d_heightMap, d_ht, width); } } extern "C" void cudaCalculateSlopeKernel(float *hptr, float2 *slopeOut, unsigned int width, unsigned int height) { dim3 block(8, 8, 1); dim3 grid2(cuda_iDivUp(width, block.x), cuda_iDivUp(height, block.y), 1); calculateSlopeKernel<<>>(hptr, slopeOut, width, height); }