1 /*
2 * Copyright 2013 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "SkBitmap.h"
9
10 #include "SkDifferentPixelsMetric.h"
11 #include "skpdiff_util.h"
12
13 static const char kDifferentPixelsKernelSource[] =
14 "#pragma OPENCL_EXTENSION cl_khr_global_int32_base_atomics \n"
15 " \n"
16 "const sampler_t gInSampler = CLK_NORMALIZED_COORDS_FALSE | \n"
17 " CLK_ADDRESS_CLAMP_TO_EDGE | \n"
18 " CLK_FILTER_NEAREST; \n"
19 " \n"
20 "__kernel void diff(read_only image2d_t baseline, read_only image2d_t test, \n"
21 " __global int* result) { \n"
22 " int2 coord = (int2)(get_global_id(0), get_global_id(1)); \n"
23 " uint4 baselinePixel = read_imageui(baseline, gInSampler, coord); \n"
24 " uint4 testPixel = read_imageui(test, gInSampler, coord); \n"
25 " if (baselinePixel.x != testPixel.x || \n"
26 " baselinePixel.y != testPixel.y || \n"
27 " baselinePixel.z != testPixel.z || \n"
28 " baselinePixel.w != testPixel.w) { \n"
29 " \n"
30 " atomic_inc(result); \n"
31 " // TODO: generate alpha mask \n"
32 " } \n"
33 "} \n";
34
getName() const35 const char* SkDifferentPixelsMetric::getName() const {
36 return "different_pixels";
37 }
38
diff(SkBitmap * baseline,SkBitmap * test,bool computeAlphaMask,bool computeRgbDiff,bool computeWhiteDiff,Result * result) const39 bool SkDifferentPixelsMetric::diff(SkBitmap* baseline, SkBitmap* test, bool computeAlphaMask,
40 bool computeRgbDiff, bool computeWhiteDiff,
41 Result* result) const {
42 double startTime = get_seconds();
43
44 if (!fIsGood) {
45 return false;
46 }
47
48 // If we never end up running the kernel, include some safe defaults in the result.
49 result->poiCount = 0;
50
51 // Ensure the images are comparable
52 if (baseline->width() != test->width() || baseline->height() != test->height() ||
53 baseline->width() <= 0 || baseline->height() <= 0 ||
54 baseline->config() != test->config()) {
55 return false;
56 }
57
58 cl_mem baselineImage;
59 cl_mem testImage;
60 cl_mem resultsBuffer;
61
62 // Upload images to the CL device
63 if (!this->makeImage2D(baseline, &baselineImage) || !this->makeImage2D(test, &testImage)) {
64 SkDebugf("creation of openCL images failed");
65 return false;
66 }
67
68 // A small hack that makes calculating percentage difference easier later on.
69 result->result = 1.0 / ((double)baseline->width() * baseline->height());
70
71 // Make a buffer to store results into. It must be initialized with pointers to memory.
72 static const int kZero = 0;
73 // We know OpenCL won't write to it because we use CL_MEM_COPY_HOST_PTR
74 resultsBuffer = clCreateBuffer(fContext, CL_MEM_READ_WRITE | CL_MEM_COPY_HOST_PTR,
75 sizeof(int), (int*)&kZero, NULL);
76
77 // Set all kernel arguments
78 cl_int setArgErr = clSetKernelArg(fKernel, 0, sizeof(cl_mem), &baselineImage);
79 setArgErr |= clSetKernelArg(fKernel, 1, sizeof(cl_mem), &testImage);
80 setArgErr |= clSetKernelArg(fKernel, 2, sizeof(cl_mem), &resultsBuffer);
81 if (CL_SUCCESS != setArgErr) {
82 SkDebugf("Set arg failed: %s\n", cl_error_to_string(setArgErr));
83 return false;
84 }
85
86 // Queue this diff on the CL device
87 cl_event event;
88 const size_t workSize[] = { baseline->width(), baseline->height() };
89 cl_int enqueueErr;
90 enqueueErr = clEnqueueNDRangeKernel(fCommandQueue, fKernel, 2, NULL, workSize,
91 NULL, 0, NULL, &event);
92 if (CL_SUCCESS != enqueueErr) {
93 SkDebugf("Enqueue failed: %s\n", cl_error_to_string(enqueueErr));
94 return false;
95 }
96
97 // This makes things totally synchronous. Actual queue is not ready yet
98 clWaitForEvents(1, &event);
99
100 // Immediate read back the results
101 clEnqueueReadBuffer(fCommandQueue, resultsBuffer, CL_TRUE, 0,
102 sizeof(int), &result->poiCount, 0, NULL, NULL);
103 result->result *= (double)result->poiCount;
104 result->result = (1.0 - result->result);
105
106 // Release all the buffers created
107 clReleaseMemObject(resultsBuffer);
108 clReleaseMemObject(baselineImage);
109 clReleaseMemObject(testImage);
110
111 result->timeElapsed = get_seconds() - startTime;
112 return true;
113 }
114
onInit()115 bool SkDifferentPixelsMetric::onInit() {
116 if (!this->loadKernelSource(kDifferentPixelsKernelSource, "diff", &fKernel)) {
117 return false;
118 }
119
120 return true;
121 }
122