1 files changed, 239 insertions, 0 deletions
diff --git a/Tools/DumpRenderTree/gtk/ImageDiff.cpp b/Tools/DumpRenderTree/gtk/ImageDiff.cpp
new file mode 100644
index 0000000..7e2744a
--- /dev/null
+++ b/Tools/DumpRenderTree/gtk/ImageDiff.cpp
@@ -0,0 +1,239 @@
+/*
+ * Copyright (C) 2009 Zan Dobersek <zandobersek@gmail.com>
+ * Copyright (C) 2010 Igalia S.L.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1.  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ * 2.  Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
+ *     its contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS 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 <algorithm>
+#include <cmath>
+#include <cstdio>
+#include <cstring>
+#include <gdk/gdk.h>
+
+using namespace std;
+
+static double tolerance = 0;
+static GOptionEntry commandLineOptionEntries[] = 
+{
+    { "tolerance", 0, 0, G_OPTION_ARG_DOUBLE, &tolerance, "Percentage difference between images before considering them different", "T" },
+    { 0, 0, 0, G_OPTION_ARG_NONE, 0, 0, 0 },
+};
+
+GdkPixbuf* readPixbufFromStdin(long imageSize)
+{
+    unsigned char imageBuffer[2048];
+    GdkPixbufLoader* loader = gdk_pixbuf_loader_new_with_type("png", 0);
+    GError* error = 0;
+
+    while (imageSize > 0) {
+        size_t bytesToRead = min<int>(imageSize, 2048);
+        size_t bytesRead = fread(imageBuffer, 1, bytesToRead, stdin);
+
+        if (!gdk_pixbuf_loader_write(loader, reinterpret_cast<const guchar*>(imageBuffer), bytesRead, &error)) {
+            g_error_free(error);
+            gdk_pixbuf_loader_close(loader, 0);
+            g_object_unref(loader);
+            return 0;
+        }
+
+        imageSize -= static_cast<int>(bytesRead);
+    }
+
+    gdk_pixbuf_loader_close(loader, 0);
+    GdkPixbuf* decodedImage = gdk_pixbuf_loader_get_pixbuf(loader);
+    g_object_ref(decodedImage);
+    return decodedImage;
+}
+
+GdkPixbuf* differenceImageFromDifferenceBuffer(unsigned char* buffer, int width, int height)
+{
+    GdkPixbuf* image = gdk_pixbuf_new(GDK_COLORSPACE_RGB, FALSE, 8, width, height);
+    if (!image)
+        return image;
+
+    int rowStride = gdk_pixbuf_get_rowstride(image);
+    unsigned char* diffPixels = gdk_pixbuf_get_pixels(image);
+    for (int x = 0; x < width; x++) {
+        for (int y = 0; y < height; y++) {
+            unsigned char* diffPixel = diffPixels + (y * rowStride) + (x * 3);
+            diffPixel[0] = diffPixel[1] = diffPixel[2] = *buffer++;
+        }
+    }
+
+    return image;
+}
+
+float calculateDifference(GdkPixbuf* baselineImage, GdkPixbuf* actualImage, GdkPixbuf** differenceImage)
+{
+    int width = gdk_pixbuf_get_width(actualImage);
+    int height = gdk_pixbuf_get_height(actualImage);
+    int numberOfChannels = gdk_pixbuf_get_n_channels(actualImage);
+    if ((width != gdk_pixbuf_get_width(baselineImage))
+        || (height != gdk_pixbuf_get_height(baselineImage))
+        || (numberOfChannels != gdk_pixbuf_get_n_channels(baselineImage))
+        || (gdk_pixbuf_get_has_alpha(actualImage) != gdk_pixbuf_get_has_alpha(baselineImage))) {
+        fprintf(stderr, "Error, test and reference image have different properties.\n");
+        return 100; // Completely different.
+    }
+
+    unsigned char* diffBuffer = static_cast<unsigned char*>(malloc(width * height));
+    float count = 0;
+    float sum = 0;
+    float maxDistance = 0;
+    int actualRowStride = gdk_pixbuf_get_rowstride(actualImage);
+    int baseRowStride = gdk_pixbuf_get_rowstride(baselineImage);
+    unsigned char* actualPixels = gdk_pixbuf_get_pixels(actualImage);
+    unsigned char* basePixels = gdk_pixbuf_get_pixels(baselineImage);
+    unsigned char* currentDiffPixel = diffBuffer;
+    for (int x = 0; x < width; x++) {
+        for (int y = 0; y < height; y++) {
+            unsigned char* actualPixel = actualPixels + (y * actualRowStride) + (x * numberOfChannels);
+            unsigned char* basePixel = basePixels + (y * baseRowStride) + (x * numberOfChannels);
+
+            float red = (actualPixel[0] - basePixel[0]) / max<float>(255 - basePixel[0], basePixel[0]);
+            float green = (actualPixel[1] - basePixel[1]) / max<float>(255 - basePixel[1], basePixel[1]);
+            float blue = (actualPixel[2] - basePixel[2]) / max<float>(255 - basePixel[2], basePixel[2]);
+            float alpha = (actualPixel[3] - basePixel[3]) / max<float>(255 - basePixel[3], basePixel[3]);
+            float distance = sqrtf(red * red + green * green + blue * blue + alpha * alpha) / 2.0f;
+
+            *currentDiffPixel++ = (unsigned char)(distance * 255.0f);
+
+            if (distance >= 1.0f / 255.0f) {
+                count += 1.0f;
+                sum += distance;
+                maxDistance = max<float>(maxDistance, distance);
+            }
+        }
+    }
+
+    // Compute the difference as a percentage combining both the number of
+    // different pixels and their difference amount i.e. the average distance
+    // over the entire image
+    float difference = 0;
+    if (count > 0.0f)
+        difference = 100.0f * sum / (height * width);
+    if (difference <= tolerance)
+        difference = 0;
+    else {
+        difference = roundf(difference * 100.0f) / 100.0f;
+        difference = max(difference, 0.01f); // round to 2 decimal places
+        *differenceImage = differenceImageFromDifferenceBuffer(diffBuffer, width, height);
+    }
+
+    free(diffBuffer);
+    return difference;
+}
+
+void printImage(GdkPixbuf* image)
+{
+    char* buffer;
+    gsize bufferSize;
+    GError* error = 0;
+    if (!gdk_pixbuf_save_to_buffer(image, &buffer, &bufferSize, "png", &error, NULL)) {
+        g_error_free(error);
+        return; // Don't bail out, as we can still use the percentage output.
+    }
+
+    printf("Content-Length: %"G_GSIZE_FORMAT"\n", bufferSize);
+    fwrite(buffer, 1, bufferSize, stdout);
+}
+
+void printImageDifferences(GdkPixbuf* baselineImage, GdkPixbuf* actualImage)
+{
+    GdkPixbuf* differenceImage = 0;
+    float difference = calculateDifference(baselineImage, actualImage, &differenceImage);
+    if (difference > 0.0f) {
+        if (differenceImage) {
+            printImage(differenceImage);
+            g_object_unref(differenceImage);
+        }
+        printf("diff: %01.2f%% failed\n", difference);
+    } else {
+        printf("diff: %01.2f%% passed\n", difference);
+    }
+}
+
+int main(int argc, char* argv[])
+{
+    gdk_init(&argc, &argv);
+
+    GError* error = 0;
+    GOptionContext* context = g_option_context_new("- compare two image files, printing their percentage difference and the difference image to stdout");
+    g_option_context_add_main_entries(context, commandLineOptionEntries, 0);
+    if (!g_option_context_parse(context, &argc, &argv, &error)) {
+        printf("Option parsing failed: %s\n", error->message);
+        g_error_free(error);
+        return 1;
+    }
+
+    GdkPixbuf* actualImage = 0;
+    GdkPixbuf* baselineImage = 0;
+    char buffer[2048];
+    while (fgets(buffer, sizeof(buffer), stdin)) {
+        // Convert the first newline into a NUL character so that strtok doesn't produce it.
+        char* newLineCharacter = strchr(buffer, '\n');
+        if (newLineCharacter)
+            *newLineCharacter = '\0';
+
+        if (!strncmp("Content-Length: ", buffer, 16)) {
+            gchar** tokens = g_strsplit(buffer, " ", 0);
+            if (!tokens[1]) {
+                g_strfreev(tokens);
+                printf("Error, image size must be specified..\n");
+                return 1;
+            }
+
+            long imageSize = strtol(tokens[1], 0, 10);
+            g_strfreev(tokens);
+            if (imageSize > 0 && !actualImage) {
+                if (!(actualImage = readPixbufFromStdin(imageSize))) {
+                    printf("Error, could not read actual image.\n");
+                    return 1;
+                }
+            } else if (imageSize > 0 && !baselineImage) {
+                if (!(baselineImage = readPixbufFromStdin(imageSize))) {
+                    printf("Error, could not read baseline image.\n");
+                    return 1;
+                }
+            } else {
+                printf("Error, image size must be specified..\n");
+                return 1;
+            }
+        }
+
+        if (actualImage && baselineImage) {
+            printImageDifferences(baselineImage, actualImage);
+            g_object_unref(actualImage);
+            g_object_unref(baselineImage);
+            actualImage = 0;
+            baselineImage = 0;
+        }
+
+        fflush(stdout);
+    }
+
+    return 0;
+}