experiment/fiddle

experimental/fiddle/fiddle_main.cpp

Index: experimental/fiddle/fiddle_main.cpp
diff --git a/experimental/fiddle/fiddle_main.cpp b/experimental/fiddle/fiddle_main.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..ca0302d9be95a63c85f1bbe52b4ed343316c4d55
--- /dev/null
+++ b/experimental/fiddle/fiddle_main.cpp
@@ -0,0 +1,145 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <stdio.h>
+
+#include "base64.h"
+#include "fiddle_main.h"
+#include "OSMesaContextHolder.h"
+
+// Globals externed in fiddle_main.h
+SkBitmap source;
+SkImage* image(nullptr);

[mtklein, 2015/09/17 13:58:22]

Just curious: you seem to be managing this manually.  Why not just make this an
SkAutoTUnref<SkImage>?

+
+const char* FLAGS_source(nullptr);

[mtklein, 2015/09/17 13:58:22]

Any reason these FLAGS_ guys aren't static?

+int32_t FLAGS_width(256);
+int32_t FLAGS_height(256);
+bool FLAGS_gpu(false);
+bool FLAGS_noraster(false);
+bool FLAGS_pdf(false);
+
+static void help() {
+    const char options[] =
+            "\nOptions:\n"
+            "    --width WIDTH   Set the canvas width (default is 256).\n"
+            "    --height HEIGHT Set the canvas height (default is 256).\n"
+            "    --source PATH   Set the source image file.\n"
+            "    --noraster      Disable the raster backend.\n"

[mtklein, 2015/09/17 13:58:22]

Why are any of these options?  Let's just run them all and, if you really want,
not show the results on the web page?  Again, not sure why we need that to be an
option either.

+            "    --gpu           Enable the GPU backend.\n"
+            "    --pdf           Enable the PDF backend.\n\n";
+    fputs(options, stderr);

[mtklein, 2015/09/17 13:58:22]

If you use fprintf you can keep your (default is %d) correct.

+    exit(2);
+}
+
+static void parse_flags(int, char** argv) {
+    ++argv; // skip argv[0]
+    while (*argv) {  // argv is always NULL-terminated
+        if (0 == strcmp(*argv, "--width")) {
+            if (!*++argv) {
+                help();
+            }
+            FLAGS_width = atoi(*argv);
+        } else if (0 == strcmp(*argv, "--height")) {
+            if (!*++argv) {
+                help();
+            }
+            FLAGS_height = atoi(*argv);
+        } else if (0 == strcmp(*argv, "--source")) {
+            if (!*++argv) {
+                help();
+            }
+            FLAGS_source = *argv;
+        } else if (0 == strcmp(*argv, "--gpu")) {
+            FLAGS_gpu = true;
+        } else if (0 == strcmp(*argv, "--noraster")) {
+            FLAGS_noraster = true;
+        } else if (0 == strcmp(*argv, "--pdf")) {
+            FLAGS_pdf = true;
+        } else {
+            help();
+        }
+        ++argv;
+    }
+}
+
+static void dump_output(SkData* pngData, const char* name, bool last = true) {
+    if (pngData) {
+        printf("\t\"%s\": \"", name);
+        EncodeToBase64(pngData->data(), pngData->size(), stdout);
+        fputs(last ? "\"\n" : "\",\n", stdout);
+    }
+}
+
+static SkData* encode_snapshot(SkSurface* surface) {
+    SkAutoTUnref<SkImage> img(surface->newImageSnapshot());
+    return img ? img->encode() : nullptr;
+}
+
+static GrContext* create_mesa_grcontext() {
+    SkAutoTUnref<const GrGLInterface> mesa(GrGLCreateMesaInterface());
+    intptr_t backend = reinterpret_cast<intptr_t>(mesa.get());
+    return backend ? GrContext::Create(kOpenGL_GrBackend, backend) : nullptr;
+}
+
+int main(int argc, char** argv) {
+    parse_flags(argc, argv);
+    if (FLAGS_source) {
+        SkAutoTUnref<SkData> data(SkData::NewFromFileName(FLAGS_source));
+        if (!data) {
+            perror("Unable to open the source image file.");

[mtklein, 2015/09/17 13:58:22]

I don't think you mean to be using perror.  perror does print the message to
stderr, yes, but also prints the error described by errno.  Our error did not
write to errno, so errno's going to be at the very least stale, probably
confusing.  You're going to get a lot of ": Undefined error: 0".

Perhaps you meant:
    #define error(fmt, ...) fprintf(stderr, fmt"\n", ##__VA_ARGS__)

+        } else {
+            image = SkImage::NewFromEncoded(data);
+            bool success = SkInstallDiscardablePixelRef(data, &source);
+            if (!image || !success) {
+                perror("Unable to decode the source image.");
+            }
+        }
+    }
+    SkISize size = SkISize::Make(FLAGS_width, FLAGS_height);
+    SkAutoTUnref<SkData> rasterData, gpuData, pdfData;
+    if (!FLAGS_noraster) {
+        SkAutoTUnref<SkSurface> rasterSurface(
+                SkSurface::NewRaster(SkImageInfo::MakeN32Premul(size)));
+        draw(rasterSurface->getCanvas());
+        rasterData.reset(encode_snapshot(rasterSurface));
+    }
+    if (FLAGS_gpu) {
+        OSMesaContextHolder osMesaContextHolder;
+        SkAutoTUnref<GrContext> grContext(create_mesa_grcontext());
+        if (!grContext) {
+            fputs("Unable to get Mesa GrContext.\n", stderr);
+        } else {
+            SkAutoTUnref<SkSurface> surface(
+                    SkSurface::NewRenderTarget(
+                            grContext,
+                            SkSurface::kNo_Budgeted,
+                            SkImageInfo::MakeN32Premul(size)));
+            if (!surface) {
+                fputs("Unable to get render surface.\n", stderr);
+                exit(1);
+            }
+            draw(surface->getCanvas());
+            gpuData.reset(encode_snapshot(surface));
+        }
+    }
+    if (FLAGS_pdf) {
+        SkDynamicMemoryWStream pdfStream;
+        SkAutoTUnref<SkDocument> document(SkDocument::CreatePDF(&pdfStream));
+        draw(document->beginPage(FLAGS_width, FLAGS_height));
+        document->close();
+        pdfData.reset(pdfStream.copyToData());
+    }
+
+    printf("{\n");
+    dump_output(rasterData, "Raster", !gpuData && !pdfData);
+    dump_output(gpuData, "Gpu", !pdfData);
+    dump_output(pdfData, "Pdf");
+    printf("}\n");
+
+    SkSafeSetNull(image);
+    return 0;
+}