added server-side breakpoint support to skiaserve

tools/skiaserve/skiaserve.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrCaps.h"
 #include "GrContextFactory.h"
 #include "SkCanvas.h"
@@ skipping 111 matching lines @@
         }
     }
     png_set_filter(png, 0, PNG_NO_FILTERS);
     png_set_rows(png, info_ptr, &rows[0]);
     png_set_write_fn(png, &out, write_png_callback, NULL);
     png_write_png(png, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
     png_destroy_write_struct(&png, NULL);
     sk_free(rows);
 }
 
+SkBitmap* getBitmapFromCanvas(SkCanvas* canvas) {
+    SkBitmap* bmp = new SkBitmap();
+    SkImageInfo info = SkImageInfo::Make(kImageWidth, kImageHeight, kRGBA_8888_SkColorType,
+                kOpaque_SkAlphaType);
+    bmp->setInfo(info);
+    if (!canvas->readPixels(bmp, 0, 0)) {
+        fprintf(stderr, "Can't read pixels\n");
+        return nullptr;
+    }
+    return bmp;
+}
+
 SkData* writeCanvasToPng(SkCanvas* canvas) {
     // capture pixels
-    SkBitmap bmp;
-    bmp.setInfo(canvas->imageInfo());
-    if (!canvas->readPixels(&bmp, 0, 0)) {
-        fprintf(stderr, "Can't read pixels\n");
-        return nullptr;
-    }
+    SkAutoTDelete<SkBitmap> bmp(getBitmapFromCanvas(canvas));
+    SkASSERT(bmp);
 
     // write to png
     SkDynamicMemoryWStream buffer;
-    write_png((const png_bytep) bmp.getPixels(), bmp.width(), bmp.height(), buffer);
+    write_png((const png_bytep) bmp->getPixels(), bmp->width(), bmp->height(), buffer);
     return buffer.copyToData();
 }
 
 SkCanvas* getCanvasFromRequest(Request* request) {
     GrContextFactory* factory = request->fContextFactory;
     SkGLContext* gl = factory->getContextInfo(GrContextFactory::kNative_GLContextType,
                                               GrContextFactory::kNone_GLContextOptions).fGLContext;
     gl->makeCurrent();
     SkASSERT(request->fDebugCanvas);
     SkCanvas* target = request->fSurface->getCanvas();
     return target;
 }
 
-SkData* setupAndDrawToCanvasReturnPng(Request* request, int n) {
+void drawToCanvas(Request* request, int n) {
     SkCanvas* target = getCanvasFromRequest(request);
     request->fDebugCanvas->drawTo(target, n);
-    return writeCanvasToPng(target);
+}
+
+SkData* drawToPng(Request* request, int n) {
+    drawToCanvas(request, n);
+    return writeCanvasToPng(getCanvasFromRequest(request));
 }
 
 SkSurface* setupCpuSurface() {
     SkImageInfo info = SkImageInfo::Make(kImageWidth, kImageHeight, kN32_SkColorType,
                                          kPremul_SkAlphaType);
     return SkSurface::NewRaster(info);
 }
 
 static const size_t kBufferSize = 1024;
 
@@ skipping 147 matching lines @@
         }
 
         int n;
         // /img or /img/N
         if (commands.count() == 1) {
             n = request->fDebugCanvas->getSize() - 1;
         } else {
             sscanf(commands[1].c_str(), "%d", &n);
         }
 
-        SkAutoTUnref<SkData> data(setupAndDrawToCanvasReturnPng(request, n));
+        SkAutoTUnref<SkData> data(drawToPng(request, n));
         return SendData(connection, data, "image/png");
     }
 };
 
+class BreakHandler : public UrlHandler {
+public:
+    bool canHandle(const char* method, const char* url) override {
+        static const char* kBasePath = "/break";
+        return 0 == strcmp(method, MHD_HTTP_METHOD_GET) &&
+               0 == strncmp(url, kBasePath, strlen(kBasePath));
+    }
+
+    static SkColor getPixel(Request* request, int x, int y) {
+        SkCanvas* canvas = getCanvasFromRequest(request);
+        SkAutoTDelete<SkBitmap> bitmap(getBitmapFromCanvas(canvas));
+        SkASSERT(bitmap);
+        bitmap->lockPixels();
+        uint8_t* start = ((uint8_t*) bitmap->getPixels()) + (y * kImageWidth + x) * 4;
+        SkColor result = SkColorSetARGB(start[3], start[0], start[1], start[2]);
+        bitmap->unlockPixels();
+        return result;
+    }
+
+    int handle(Request* request, MHD_Connection* connection,
+               const char* url, const char* method,
+               const char* upload_data, size_t* upload_data_size) override {
+        SkTArray<SkString> commands;
+        SkStrSplit(url, "/", &commands);
+
+        if (!request->fPicture.get() || commands.count() != 4) {
+            return MHD_NO;
+        }
+
+        // /break/<n>/<x>/<y>
+        int n;
+        sscanf(commands[1].c_str(), "%d", &n);
+        int x;
+        sscanf(commands[2].c_str(), "%d", &x);
+        int y;
+        sscanf(commands[3].c_str(), "%d", &y);
+
+        drawToCanvas(request, n);
+        SkColor target = getPixel(request, x, y);
+        SkCanvas* canvas = getCanvasFromRequest(request);
+        Json::Value response(Json::objectValue);
+        Json::Value startColor(Json::arrayValue);
+        startColor.append(Json::Value(SkColorGetR(target)));
+        startColor.append(Json::Value(SkColorGetG(target)));
+        startColor.append(Json::Value(SkColorGetB(target)));
+        startColor.append(Json::Value(SkColorGetA(target)));
+        response["startColor"] = startColor;
+        response["endColor"] = startColor;
+        response["endOp"] = Json::Value(-1);
+        for (int i = n + 1; i < request->fDebugCanvas->getSize(); ++i) {

[jcgregorio, 2016/02/18 13:48:11]

Actually can you wrap around? I.e. if you each the last op and the color hasn't
changed can you then look for a change in ops [0, n-1]? This would match what
currently happens when you reach the end of the list of ops.

+            request->fDebugCanvas->getDrawCommandAt(i)->execute(canvas);
+            canvas->flush();
+            SkColor current = getPixel(request, x, y);
+            if (current != target) {
+                Json::Value endColor(Json::arrayValue);
+                endColor.append(Json::Value(SkColorGetR(current)));
+                endColor.append(Json::Value(SkColorGetG(current)));
+                endColor.append(Json::Value(SkColorGetB(current)));
+                endColor.append(Json::Value(SkColorGetA(current)));
+                response["endColor"] = endColor;
+                response["endOp"] = Json::Value(i);
+                break;
+            }
+        }
+        SkDynamicMemoryWStream stream;
+        stream.writeText(Json::FastWriter().write(response).c_str());
+        SkAutoTUnref<SkData> data(stream.copyToData());
+        return SendData(connection, data, "application/json");
+    }
+};
+
 /**
    Updates the clip visualization alpha. On all subsequent /img requests, the clip will be drawn in
    black with the specified alpha. 0 = no visible clip, 255 = fully opaque clip.
  */
 class ClipAlphaHandler : public UrlHandler {
 public:
     bool canHandle(const char* method, const char* url) override {
         static const char* kBasePath = "/clipAlpha/";
         return 0 == strcmp(method, MHD_HTTP_METHOD_POST) &&
                0 == strncmp(url, kBasePath, strlen(kBasePath));
@@ skipping 233 matching lines @@
         // Register handlers
         fHandlers.push_back(new RootHandler);
         fHandlers.push_back(new PostHandler);
         fHandlers.push_back(new ImgHandler);
         fHandlers.push_back(new ClipAlphaHandler);
         fHandlers.push_back(new CmdHandler);
         fHandlers.push_back(new InfoHandler);
         fHandlers.push_back(new DownloadHandler);
         fHandlers.push_back(new DataHandler);
         fHandlers.push_back(new FaviconHandler);
+        fHandlers.push_back(new BreakHandler);
     }
 
     ~UrlManager() {
         for (int i = 0; i < fHandlers.count(); i++) { delete fHandlers[i]; }
     }
 
     // This is clearly not efficient for a large number of urls and handlers
     int invoke(Request* request, MHD_Connection* connection, const char* url, const char* method,
                const char* upload_data, size_t* upload_data_size) const {
         for (int i = 0; i < fHandlers.count(); i++) {
@@ skipping 41 matching lines @@
     MHD_stop_daemon(daemon);
     return 0;
 }
 
 #if !defined SK_BUILD_FOR_IOS
 int main(int argc, char** argv) {
     SkCommandLineFlags::Parse(argc, argv);
     return skiaserve_main();
 }
 #endif