experimental/tools/coreGraphicsPdf2png: remove skia dependency

experimental/tools/coreGraphicsPdf2png.cpp

 /*
  * 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>
+//  c++ --std=c++11 coreGraphicsPdf2png.cpp -o coreGraphicsPdf2png  -framework ApplicationServices
 
-#include "SkBitmap.h"
-#include "SkCGUtils.h"
-#include "SkForceLinking.h"
-#include "SkImageEncoder.h"
-#include "SkStream.h"
+#include <cstdio>
+#include <memory>
 
-__SK_FORCE_IMAGE_DECODER_LINKING;
+#include <ApplicationServices/ApplicationServices.h>
 
-class StdOutWStream : public SkWStream {
-public:
-    StdOutWStream() : fBytesWritten(0) {}
-    bool write(const void* buffer, size_t size) final {
-        fBytesWritten += size;
-        return size == fwrite(buffer, 1, size, stdout);
+#define ASSERT(x)                                \
+    do {                                         \
+        if (!(x)) {                              \
+            fprintf(stderr, "ERROR: " __FILE__   \
+                    ":%d (%s)\n", __LINE__, #x); \
+            return 1;                            \
+        }                                        \
+    } while (false)                              \
+
+const int PAGE = 1;
+
+int main(int argc, char** argv) {
+    if (argc <= 1 || !*(argv[1]) || 0 == strcmp(argv[1], "-")) {
+        fprintf(stderr, "usage:\n\t%s INPUT_PDF_FILE_PATH [OUTPUT_PNG_PATH]\n", argv[0]);
+        return 1;
     }
-    size_t bytesWritten() const final { return fBytesWritten; }
-
-private:
-    size_t fBytesWritten;
-};
-
-static SkStreamAsset* open_for_reading(const char* path) {
-    if (!path || !path[0] || 0 == strcmp(path, "-")) {
-        return new SkFILEStream(stdin, SkFILEStream::kCallerRetains_Ownership);
-    }
-    return SkStream::NewFromFile(path);
+    const char* output = argc > 2 ? argv[2] : nullptr;
+    CGDataProviderRef data = CGDataProviderCreateWithFilename(argv[1]);
+    ASSERT(data);
+    CGPDFDocumentRef pdf = CGPDFDocumentCreateWithProvider(data);
+    CGDataProviderRelease(data);
+    ASSERT(pdf);
+    CGPDFPageRef page = CGPDFDocumentGetPage(pdf, PAGE);
+    ASSERT(page);
+    CGRect bounds = CGPDFPageGetBoxRect(page, kCGPDFMediaBox);
+    int w = (int)CGRectGetWidth(bounds);
+    int h = (int)CGRectGetHeight(bounds);
+    CGBitmapInfo info = kCGBitmapByteOrder32Big | kCGImageAlphaPremultipliedLast;
+    CGColorSpaceRef cs = CGColorSpaceCreateDeviceRGB();
+    ASSERT(cs);
+    std::unique_ptr<uint32_t[]> bitmap(new uint32_t[w * h]);
+    memset(bitmap.get(), 0xFF, 4 * w * h);
+    CGContextRef ctx = CGBitmapContextCreate(bitmap.get(), w, h, 8, w * 4, cs, info);
+    ASSERT(ctx);
+    CGContextDrawPDFPage(ctx, page);
+    CGPDFDocumentRelease(pdf);
+    CGImageRef image = CGBitmapContextCreateImage(ctx);
+    ASSERT(image);
+    CGDataConsumerCallbacks procs;
+    procs.putBytes = [](void* f, const void* buf, size_t s) {
+        return fwrite(buf, 1, s, (FILE*)f);
+    };
+    procs.releaseConsumer = [](void* info) { fclose((FILE*)info); };
+    FILE* ofile = (!output || !output[0] || 0 == strcmp(output, "-"))
+        ? stdout : fopen(output, "wb");
+    ASSERT(ofile);
+    CGDataConsumerRef consumer = CGDataConsumerCreate(ofile, &procs);
+    ASSERT(consumer);
+    CGImageDestinationRef dst =
+        CGImageDestinationCreateWithDataConsumer(consumer, kUTTypePNG, 1, nullptr);
+    CFRelease(consumer);
+    ASSERT(dst);
+    CGImageDestinationAddImage(dst, image, nullptr);
+    ASSERT(CGImageDestinationFinalize(dst));
+    CFRelease(dst);
+    CGImageRelease(image);
+    CGColorSpaceRelease(cs);
+    CGContextRelease(ctx);
+    return 0;
 }
 
-static SkWStream* open_for_writing(const char* path) {
-    if (!path || !path[0] || 0 == strcmp(path, "-")) {
-        return new StdOutWStream;
-    }
-    return new SkFILEWStream(path);
-}
 
-static bool to_png(SkWStream* o, const SkBitmap& bm) {
-    return SkImageEncoder::EncodeStream(o, bm, SkImageEncoder::kPNG_Type, 100);
-}
-
-// Note: I could implement this using only MacOS|CG API calls, but
-// since most of this is already done in Skia, here it is.
-int main(int argc, char** argv) {
-    SkBitmap bm;
-    SkAutoTDelete<SkStream> in(open_for_reading(argc > 1 ? argv[1] : NULL));
-    SkAutoTDelete<SkWStream> out(open_for_writing(argc > 2 ? argv[2] : NULL));
-    if (SkPDFDocumentToBitmap(in.release(), &bm) && to_png(out, bm)) {
-        return 0;
-    } else {
-        return 1;
-    }
-}