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nvidia-texture-tools/src/nvimage/nvtt/cuda/CompressKernel.cu

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// Copyright NVIDIA Corporation 2007 -- Ignacio Castano <icastano@nvidia.com>
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include "CudaMath.h"
#define NUM_THREADS 64 // Number of threads per block.
#if __DEVICE_EMULATION__
#define __debugsync() __syncthreads()
#else
#define __debugsync()
#endif
typedef unsigned short ushort;
typedef unsigned int uint;
template <class T>
__device__ inline void swap(T & a, T & b)
{
T tmp = a;
a = b;
b = tmp;
}
__constant__ float3 kColorMetric = { 1.0f, 1.0f, 1.0f };
////////////////////////////////////////////////////////////////////////////////
// Round color to RGB565 and expand
////////////////////////////////////////////////////////////////////////////////
inline __device__ float3 roundAndExpand(float3 v, ushort * w)
{
v.x = rintf(__saturatef(v.x) * 31.0f);
v.y = rintf(__saturatef(v.y) * 63.0f);
v.z = rintf(__saturatef(v.z) * 31.0f);
*w = ((ushort)v.x << 11) | ((ushort)v.y << 5) | (ushort)v.z;
v.x *= 0.03227752766457f; // approximate integer bit expansion.
v.y *= 0.01583151765563f;
v.z *= 0.03227752766457f;
return v;
}
////////////////////////////////////////////////////////////////////////////////
// Evaluate permutations
////////////////////////////////////////////////////////////////////////////////
static __device__ float evalPermutation4(const float3 * colors, uint permutation, ushort * start, ushort * end)
{
// Compute endpoints using least squares.
float alpha2_sum = 0.0f;
float beta2_sum = 0.0f;
float alphabeta_sum = 0.0f;
float3 alphax_sum = make_float3(0.0f, 0.0f, 0.0f);
float3 betax_sum = make_float3(0.0f, 0.0f, 0.0f);
// Compute alpha & beta for this permutation.
for (int i = 0; i < 16; i++)
{
const uint bits = permutation >> (2*i);
float beta = (bits & 1);
if (bits & 2) beta = (1 + beta) / 3.0f;
float alpha = 1.0f - beta;
alpha2_sum += alpha * alpha;
beta2_sum += beta * beta;
alphabeta_sum += alpha * beta;
alphax_sum += alpha * colors[i];
betax_sum += beta * colors[i];
}
const float factor = 1.0f / (alpha2_sum * beta2_sum - alphabeta_sum * alphabeta_sum);
float3 a = (alphax_sum * beta2_sum - betax_sum * alphabeta_sum) * factor;
float3 b = (betax_sum * alpha2_sum - alphax_sum * alphabeta_sum) * factor;
// Round a, b to the closest 5-6-5 color and expand...
a = roundAndExpand(a, start);
b = roundAndExpand(b, end);
// compute the error
float3 e = a * a * alpha2_sum + b * b * beta2_sum + 2.0f * (a * b * alphabeta_sum - a * alphax_sum - b * betax_sum);
return dot(e, kColorMetric);
}
static __device__ float evalPermutation3(const float3 * colors, uint permutation, ushort * start, ushort * end)
{
// Compute endpoints using least squares.
float alpha2_sum = 0.0f;
float beta2_sum = 0.0f;
float alphabeta_sum = 0.0f;
float3 alphax_sum = make_float3(0.0f, 0.0f, 0.0f);
float3 betax_sum = make_float3(0.0f, 0.0f, 0.0f);
// Compute alpha & beta for this permutation.
for (int i = 0; i < 16; i++)
{
const uint bits = permutation >> (2*i);
float beta = (bits & 1);
if (bits & 2) beta = 0.5f;
float alpha = 1.0f - beta;
alpha2_sum += alpha * alpha;
beta2_sum += beta * beta;
alphabeta_sum += alpha * beta;
alphax_sum += alpha * colors[i];
betax_sum += beta * colors[i];
}
const float factor = 1.0f / (alpha2_sum * beta2_sum - alphabeta_sum * alphabeta_sum);
float3 a = (alphax_sum * beta2_sum - betax_sum * alphabeta_sum) * factor;
float3 b = (betax_sum * alpha2_sum - alphax_sum * alphabeta_sum) * factor;
// Round a, b to the closest 5-6-5 color and expand...
a = roundAndExpand(a, start);
b = roundAndExpand(b, end);
// compute the error
float3 e = a * a * alpha2_sum + b * b * beta2_sum + 2.0f * (a * b * alphabeta_sum - a * alphax_sum - b * betax_sum);
return dot(e, kColorMetric);
}
static __device__ float evalPermutation4(const float3 * colors, const float * weights, uint permutation, ushort * start, ushort * end)
{
// Compute endpoints using least squares.
float alpha2_sum = 0.0f;
float beta2_sum = 0.0f;
float alphabeta_sum = 0.0f;
float3 alphax_sum = make_float3(0.0f, 0.0f, 0.0f);
float3 betax_sum = make_float3(0.0f, 0.0f, 0.0f);
// Compute alpha & beta for this permutation.
for (int i = 0; i < 16; i++)
{
const uint bits = permutation >> (2*i);
float beta = (bits & 1);
if (bits & 2) beta = (1 + beta) / 3.0f;
float alpha = 1.0f - beta;
alpha2_sum += alpha * alpha * weights[i];
beta2_sum += beta * beta * weights[i];
alphabeta_sum += alpha * beta * weights[i];
alphax_sum += alpha * colors[i] * weights[i];
betax_sum += beta * colors[i] * weights[i];
}
const float factor = 1.0f / (alpha2_sum * beta2_sum - alphabeta_sum * alphabeta_sum);
float3 a = (alphax_sum * beta2_sum - betax_sum * alphabeta_sum) * factor;
float3 b = (betax_sum * alpha2_sum - alphax_sum * alphabeta_sum) * factor;
// Round a, b to the closest 5-6-5 color and expand...
a = roundAndExpand(a, start);
b = roundAndExpand(b, end);
// compute the error
float3 e = a * a * alpha2_sum + b * b * beta2_sum + 2.0f * (a * b * alphabeta_sum - a * alphax_sum - b * betax_sum);
return dot(e, kColorMetric);
}
static __device__ float evalPermutation3(const float3 * colors, const float * weights, uint permutation, ushort * start, ushort * end)
{
// Compute endpoints using least squares.
float alpha2_sum = 0.0f;
float beta2_sum = 0.0f;
float alphabeta_sum = 0.0f;
float3 alphax_sum = make_float3(0.0f, 0.0f, 0.0f);
float3 betax_sum = make_float3(0.0f, 0.0f, 0.0f);
// Compute alpha & beta for this permutation.
for (int i = 0; i < 16; i++)
{
const uint bits = permutation >> (2*i);
float beta = (bits & 1);
if (bits & 2) beta = 0.5f;
float alpha = 1.0f - beta;
alpha2_sum += alpha * alpha * weights[i];
beta2_sum += beta * beta * weights[i];
alphabeta_sum += alpha * beta * weights[i];
alphax_sum += alpha * colors[i] * weights[i];
betax_sum += beta * colors[i] * weights[i];
}
const float factor = 1.0f / (alpha2_sum * beta2_sum - alphabeta_sum * alphabeta_sum);
float3 a = (alphax_sum * beta2_sum - betax_sum * alphabeta_sum) * factor;
float3 b = (betax_sum * alpha2_sum - alphax_sum * alphabeta_sum) * factor;
// Round a, b to the closest 5-6-5 color and expand...
a = roundAndExpand(a, start);
b = roundAndExpand(b, end);
// compute the error
float3 e = a * a * alpha2_sum + b * b * beta2_sum + 2.0f * (a * b * alphabeta_sum - a * alphax_sum - b * betax_sum);
return dot(e, kColorMetric);
}
////////////////////////////////////////////////////////////////////////////////
// Sort colors
////////////////////////////////////////////////////////////////////////////////
__device__ void sortColors(float * values, float3 * colors, int * cmp)
{
int tid = threadIdx.x;
cmp[tid] = (values[0] < values[tid]);
cmp[tid] += (values[1] < values[tid]);
cmp[tid] += (values[2] < values[tid]);
cmp[tid] += (values[3] < values[tid]);
cmp[tid] += (values[4] < values[tid]);
cmp[tid] += (values[5] < values[tid]);
cmp[tid] += (values[6] < values[tid]);
cmp[tid] += (values[7] < values[tid]);
cmp[tid] += (values[8] < values[tid]);
cmp[tid] += (values[9] < values[tid]);
cmp[tid] += (values[10] < values[tid]);
cmp[tid] += (values[11] < values[tid]);
cmp[tid] += (values[12] < values[tid]);
cmp[tid] += (values[13] < values[tid]);
cmp[tid] += (values[14] < values[tid]);
cmp[tid] += (values[15] < values[tid]);
// Resolve elements with the same index.
if (tid > 0 && cmp[tid] == cmp[0]) ++cmp[tid];
if (tid > 1 && cmp[tid] == cmp[1]) ++cmp[tid];
if (tid > 2 && cmp[tid] == cmp[2]) ++cmp[tid];
if (tid > 3 && cmp[tid] == cmp[3]) ++cmp[tid];
if (tid > 4 && cmp[tid] == cmp[4]) ++cmp[tid];
if (tid > 5 && cmp[tid] == cmp[5]) ++cmp[tid];
if (tid > 6 && cmp[tid] == cmp[6]) ++cmp[tid];
if (tid > 7 && cmp[tid] == cmp[7]) ++cmp[tid];
if (tid > 8 && cmp[tid] == cmp[8]) ++cmp[tid];
if (tid > 9 && cmp[tid] == cmp[9]) ++cmp[tid];
if (tid > 10 && cmp[tid] == cmp[10]) ++cmp[tid];
if (tid > 11 && cmp[tid] == cmp[11]) ++cmp[tid];
if (tid > 12 && cmp[tid] == cmp[12]) ++cmp[tid];
if (tid > 13 && cmp[tid] == cmp[13]) ++cmp[tid];
if (tid > 14 && cmp[tid] == cmp[14]) ++cmp[tid];
float3 tmp = colors[tid];
colors[cmp[tid]] = tmp;
}
__device__ void sortColors(float * values, float3 * colors, float * weights, int * cmp)
{
int tid = threadIdx.x;
cmp[tid] = (values[0] < values[tid]);
cmp[tid] += (values[1] < values[tid]);
cmp[tid] += (values[2] < values[tid]);
cmp[tid] += (values[3] < values[tid]);
cmp[tid] += (values[4] < values[tid]);
cmp[tid] += (values[5] < values[tid]);
cmp[tid] += (values[6] < values[tid]);
cmp[tid] += (values[7] < values[tid]);
cmp[tid] += (values[8] < values[tid]);
cmp[tid] += (values[9] < values[tid]);
cmp[tid] += (values[10] < values[tid]);
cmp[tid] += (values[11] < values[tid]);
cmp[tid] += (values[12] < values[tid]);
cmp[tid] += (values[13] < values[tid]);
cmp[tid] += (values[14] < values[tid]);
cmp[tid] += (values[15] < values[tid]);
// Resolve elements with the same index.
if (tid > 0 && cmp[tid] == cmp[0]) ++cmp[tid];
if (tid > 1 && cmp[tid] == cmp[1]) ++cmp[tid];
if (tid > 2 && cmp[tid] == cmp[2]) ++cmp[tid];
if (tid > 3 && cmp[tid] == cmp[3]) ++cmp[tid];
if (tid > 4 && cmp[tid] == cmp[4]) ++cmp[tid];
if (tid > 5 && cmp[tid] == cmp[5]) ++cmp[tid];
if (tid > 6 && cmp[tid] == cmp[6]) ++cmp[tid];
if (tid > 7 && cmp[tid] == cmp[7]) ++cmp[tid];
if (tid > 8 && cmp[tid] == cmp[8]) ++cmp[tid];
if (tid > 9 && cmp[tid] == cmp[9]) ++cmp[tid];
if (tid > 10 && cmp[tid] == cmp[10]) ++cmp[tid];
if (tid > 11 && cmp[tid] == cmp[11]) ++cmp[tid];
if (tid > 12 && cmp[tid] == cmp[12]) ++cmp[tid];
if (tid > 13 && cmp[tid] == cmp[13]) ++cmp[tid];
if (tid > 14 && cmp[tid] == cmp[14]) ++cmp[tid];
float3 tmp = colors[tid];
colors[cmp[tid]] = tmp;
weights[cmp[tid]] = weights[tid];
}
////////////////////////////////////////////////////////////////////////////////
// Find index with minimum error
////////////////////////////////////////////////////////////////////////////////
__device__ void minimizeError(float * errors, int * indices)
{
const int idx = threadIdx.x;
#if __DEVICE_EMULATION__
for(int d = NUM_THREADS/2; d > 0; d >>= 1)
{
__syncthreads();
if (idx < d)
{
float err0 = errors[idx];
float err1 = errors[idx + d];
if (err1 < err0) {
errors[idx] = err1;
indices[idx] = indices[idx + d];
}
}
}
#else
for(int d = NUM_THREADS/2; d > 32; d >>= 1)
{
__syncthreads();
if (idx < d)
{
float err0 = errors[idx];
float err1 = errors[idx + d];
if (err1 < err0) {
errors[idx] = err1;
indices[idx] = indices[idx + d];
}
}
}
// unroll last 6 steps
if (idx <= 32)
{
if (errors[idx + 32] < errors[idx]) {
errors[idx] = errors[idx + 32];
indices[idx] = indices[idx + 32];
}
if (errors[idx + 16] < errors[idx]) {
errors[idx] = errors[idx + 16];
indices[idx] = indices[idx + 16];
}
if (errors[idx + 8] < errors[idx]) {
errors[idx] = errors[idx + 8];
indices[idx] = indices[idx + 8];
}
if (errors[idx + 4] < errors[idx]) {
errors[idx] = errors[idx + 4];
indices[idx] = indices[idx + 4];
}
if (errors[idx + 2] < errors[idx]) {
errors[idx] = errors[idx + 2];
indices[idx] = indices[idx + 2];
}
if (errors[idx + 1] < errors[idx]) {
errors[idx] = errors[idx + 1];
indices[idx] = indices[idx + 1];
}
}
#endif
}
////////////////////////////////////////////////////////////////////////////////
// Compress color block
////////////////////////////////////////////////////////////////////////////////
__global__ void compress(const uint * permutations, const uint * image, uint2 * result)
{
const int bid = blockIdx.x;
const int idx = threadIdx.x;
__shared__ float3 colors[16];
__shared__ float dps[16];
__shared__ int xrefs[16];
if (idx < 16)
{
// Read color and copy to shared mem.
uint c = image[(bid) * 16 + idx];
colors[idx].z = ((c >> 0) & 0xFF) * (1.0f / 255.0f);
colors[idx].y = ((c >> 8) & 0xFF) * (1.0f / 255.0f);
colors[idx].x = ((c >> 16) & 0xFF) * (1.0f / 255.0f);
// No need to synchronize, 16 < warp size.
#if __DEVICE_EMULATION__
} __debugsync(); if (idx < 16) {
#endif
// Sort colors along the best fit line.
float3 axis = bestFitLine(colors);
dps[idx] = dot(colors[idx], axis);
#if __DEVICE_EMULATION__
} __debugsync(); if (idx < 16) {
#endif
sortColors(dps, colors, xrefs);
}
ushort bestStart, bestEnd;
uint bestPermutation;
float bestError = FLT_MAX;
__syncthreads();
#if 0
// This version is more clear, but slightly slower.
for(int i = 0; i < 16; i++)
{
if (i == 15 && idx >= 32) break;
ushort start, end;
uint permutation = permutations[idx + NUM_THREADS * i];
float error = evalPermutation4(colors, permutation, &start, &end);
if (error < bestError)
{
bestError = error;
bestPermutation = permutation;
bestStart = start;
bestEnd = end;
}
}
if (bestStart < bestEnd)
{
swap(bestEnd, bestStart);
bestPermutation ^= 0x55555555; // Flip indices.
}
for(int i = 0; i < 3; i++)
{
if (i == 2 && idx >= 32) break;
ushort start, end;
uint permutation = permutations[idx + NUM_THREADS * i];
float error = evalPermutation3(colors, permutation, &start, &end);
if (error < bestError)
{
bestError = error;
bestPermutation = permutation;
bestStart = start;
bestEnd = end;
if (bestStart > bestEnd)
{
swap(bestEnd, bestStart);
bestPermutation ^= (~bestPermutation >> 1) & 0x55555555; // Flip indices.
}
}
}
#else
{
int pidx = idx + NUM_THREADS * 15;
if (idx >= 32)
{
pidx = idx + NUM_THREADS * 2;
}
ushort start, end;
uint permutation = permutations[pidx];
float error = evalPermutation4(colors, permutation, &start, &end);
if (error < bestError)
{
bestError = error;
bestPermutation = permutation;
bestStart = start;
bestEnd = end;
}
}
for(int i = 3; i < 15; i++)
{
ushort start, end;
uint permutation = permutations[idx + NUM_THREADS * i];
float error = evalPermutation4(colors, permutation, &start, &end);
if (error < bestError)
{
bestError = error;
bestPermutation = permutation;
bestStart = start;
bestEnd = end;
}
}
if (bestStart < bestEnd)
{
swap(bestEnd, bestStart);
bestPermutation ^= 0x55555555; // Flip indices.
}
for(int i = 0; i < 3; i++)
{
if (i == 2 && idx >= 32) break;
ushort start, end;
uint permutation = permutations[idx + NUM_THREADS * i];
float error = evalPermutation3(colors, permutation, &start, &end);
if (error < bestError)
{
bestError = error;
bestPermutation = permutation;
bestStart = start;
bestEnd = end;
if (bestStart > bestEnd)
{
swap(bestEnd, bestStart);
bestPermutation ^= (~bestPermutation >> 1) & 0x55555555; // Flip indices.
}
}
error = evalPermutation4(colors, permutation, &start, &end);
if (error < bestError)
{
bestError = error;
bestPermutation = permutation;
bestStart = start;
bestEnd = end;
if (bestStart < bestEnd)
{
swap(bestEnd, bestStart);
bestPermutation ^= 0x55555555; // Flip indices.
}
}
}
#endif
__syncthreads();
// Use a parallel reduction to find minimum error.
__shared__ float errors[NUM_THREADS];
__shared__ int indices[NUM_THREADS];
errors[idx] = bestError;
indices[idx] = idx;
minimizeError(errors, indices);
__syncthreads();
// Only write the result of the winner thread.
if (idx == indices[0])
{
if (bestStart == bestEnd)
{
bestPermutation = 0;
}
// Reorder permutation.
uint perm = 0;
for(int i = 0; i < 16; i++)
{
int ref = xrefs[i];
perm |= ((bestPermutation >> (2 * ref)) & 3) << (2 * i);
}
// Write endpoints. (bestStart, bestEnd)
result[bid].x = (bestEnd << 16) | bestStart;
// Write palette indices (permutation).
result[bid].y = perm;
}
}
__global__ void compressWeighted(const uint * permutations, const uint * image, uint2 * result)
{
const int bid = blockIdx.x;
const int idx = threadIdx.x;
__shared__ float3 colors[16];
__shared__ float weights[16];
__shared__ float dps[16];
__shared__ int xrefs[16];
if (idx < 16)
{
// Read color and copy to shared mem.
uint c = image[(bid) * 16 + idx];
colors[idx].z = ((c >> 0) & 0xFF) * (1.0f / 255.0f);
colors[idx].y = ((c >> 8) & 0xFF) * (1.0f / 255.0f);
colors[idx].x = ((c >> 16) & 0xFF) * (1.0f / 255.0f);
weights[idx] = ((c >> 24) & 0xFF) * (1.0f / 255.0f);
// No need to synchronize, 16 < warp size.
#if __DEVICE_EMULATION__
} __debugsync(); if (idx < 16) {
#endif
// Sort colors along the best fit line.
float3 axis = bestFitLine(colors);
dps[idx] = dot(colors[idx], axis);
#if __DEVICE_EMULATION__
} __debugsync(); if (idx < 16) {
#endif
sortColors(dps, colors, weights, xrefs);
}
ushort bestStart, bestEnd;
uint bestPermutation;
float bestError = FLT_MAX;
__syncthreads();
#if 0
// This version is more clear, but slightly slower.
for(int i = 0; i < 16; i++)
{
if (i == 15 && idx >= 32) break;
ushort start, end;
uint permutation = permutations[idx + NUM_THREADS * i];
float error = evalPermutation4(colors, weights, permutation, &start, &end);
if (error < bestError)
{
bestError = error;
bestPermutation = permutation;
bestStart = start;
bestEnd = end;
}
}
if (bestStart < bestEnd)
{
swap(bestEnd, bestStart);
bestPermutation ^= 0x55555555; // Flip indices.
}
for(int i = 0; i < 3; i++)
{
if (i == 2 && idx >= 32) break;
ushort start, end;
uint permutation = permutations[idx + NUM_THREADS * i];
float error = evalPermutation3(colors, weights, permutation, &start, &end);
if (error < bestError)
{
bestError = error;
bestPermutation = permutation;
bestStart = start;
bestEnd = end;
if (bestStart > bestEnd)
{
swap(bestEnd, bestStart);
bestPermutation ^= (~bestPermutation >> 1) & 0x55555555; // Flip indices.
}
}
}
#else
{
int pidx = idx + NUM_THREADS * 15;
if (idx >= 32)
{
pidx = idx + NUM_THREADS * 2;
}
ushort start, end;
uint permutation = permutations[pidx];
float error = evalPermutation4(colors, weights, permutation, &start, &end);
if (error < bestError)
{
bestError = error;
bestPermutation = permutation;
bestStart = start;
bestEnd = end;
}
}
for(int i = 3; i < 15; i++)
{
ushort start, end;
uint permutation = permutations[idx + NUM_THREADS * i];
float error = evalPermutation4(colors, weights, permutation, &start, &end);
if (error < bestError)
{
bestError = error;
bestPermutation = permutation;
bestStart = start;
bestEnd = end;
}
}
if (bestStart < bestEnd)
{
swap(bestEnd, bestStart);
bestPermutation ^= 0x55555555; // Flip indices.
}
for(int i = 0; i < 3; i++)
{
if (i == 2 && idx >= 32) break;
ushort start, end;
uint permutation = permutations[idx + NUM_THREADS * i];
float error = evalPermutation3(colors, weights, permutation, &start, &end);
if (error < bestError)
{
bestError = error;
bestPermutation = permutation;
bestStart = start;
bestEnd = end;
if (bestStart > bestEnd)
{
swap(bestEnd, bestStart);
bestPermutation ^= (~bestPermutation >> 1) & 0x55555555; // Flip indices.
}
}
error = evalPermutation4(colors, weights, permutation, &start, &end);
if (error < bestError)
{
bestError = error;
bestPermutation = permutation;
bestStart = start;
bestEnd = end;
if (bestStart < bestEnd)
{
swap(bestEnd, bestStart);
bestPermutation ^= 0x55555555; // Flip indices.
}
}
}
#endif
__syncthreads();
// Use a parallel reduction to find minimum error.
__shared__ float errors[NUM_THREADS];
__shared__ int indices[NUM_THREADS];
errors[idx] = bestError;
indices[idx] = idx;
minimizeError(errors, indices);
__syncthreads();
// Only write the result of the winner thread.
if (idx == indices[0])
{
if (bestStart == bestEnd)
{
bestPermutation = 0;
}
// Reorder permutation.
uint perm = 0;
for(int i = 0; i < 16; i++)
{
int ref = xrefs[i];
perm |= ((bestPermutation >> (2 * ref)) & 3) << (2 * i);
}
// Write endpoints. (bestStart, bestEnd)
result[bid].x = (bestEnd << 16) | bestStart;
// Write palette indices (permutation).
result[bid].y = perm;
}
}
////////////////////////////////////////////////////////////////////////////////
// Setup kernel
////////////////////////////////////////////////////////////////////////////////
extern "C" void setupCompressKernel(const float weights[3])
{
// Set constants.
cudaMemcpyToSymbol(kColorMetric, weights, sizeof(float) * 3, 0);
}
////////////////////////////////////////////////////////////////////////////////
// Launch kernel
////////////////////////////////////////////////////////////////////////////////
extern "C" void compressKernel(uint blockNum, uint * d_data, uint * d_result, uint * d_bitmaps)
{
compress<<<blockNum, NUM_THREADS>>>(d_bitmaps, d_data, (uint2 *)d_result);
}
extern "C" void compressWeightedKernel(uint blockNum, uint * d_data, uint * d_result, uint * d_bitmaps)
{
compressWeighted<<<blockNum, NUM_THREADS>>>(d_bitmaps, d_data, (uint2 *)d_result);
}