Add plumbing for text only fiddles.

BUG=skia:

Change-Id: If3967f868c482bbded7185a0ed7c6559cd2858c5
Reviewed-on: https://skia-review.googlesource.com/8334
Reviewed-by: Cary Clark <caryclark@google.com>
Commit-Queue: Joe Gregorio <jcgregorio@google.com>

tools/fiddle/draw.cpp

@@ -13,7 +13,7 @@
 DrawOptions GetDrawOptions() {
     // path *should* be absolute.
     static const char path[] = "resources/color_wheel.png";
-    return DrawOptions(256, 256, true, true, true, true, true, false, path);
+    return DrawOptions(256, 256, true, true, true, true, true, false, false, path);
 }
 void draw(SkCanvas* canvas) {
     canvas->clear(SK_ColorWHITE);
@@ -25,4 +25,5 @@ void draw(SkCanvas* canvas) {
                                       SkShader::kRepeat_TileMode,
                                       &matrix));
     canvas->drawPaint(paint);
+    SkDebugf("This is text output: %d", 2);
 }

tools/fiddle/fiddle_main.cpp

@@ -7,6 +7,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string>
 
 #include "fiddle_main.h"
 
@@ -14,6 +15,22 @@
 SkBitmap source;
 sk_sp<SkImage> image;
 
+// Globals used by the local impl of SkDebugf.
+char formatbuffer[1024];
+std::string textoutput("");
+
+void SkDebugf(const char * fmt, ...) {
+    int n;
+    va_list args;
+    va_start(args, fmt);
+    n = vsnprintf(formatbuffer, sizeof(formatbuffer), fmt, args);
+    va_end(args);
+    if (n>=0 && n<=int(sizeof(formatbuffer))) {
+        textoutput.append(formatbuffer);
+        textoutput.append("\n");
+    }
+}
+
 static void encode_to_base64(const void* data, size_t size, FILE* out) {
     const uint8_t* input = reinterpret_cast<const uint8_t*>(data);
     const uint8_t* end = &input[size];
@@ -56,6 +73,13 @@ static void dump_output(const sk_sp<SkData>& data,
     }
 }
 
+static void dump_text(const std::string& s,
+                        const char* name, bool last = true) {
+    printf("\t\"%s\": \"", name);
+    encode_to_base64(s.c_str(), s.length(), stdout);
+    fputs(last ? "\"\n" : "\",\n", stdout);
+}
+
 static SkData* encode_snapshot(const sk_sp<SkSurface>& surface) {
     sk_sp<SkImage> img(surface->makeImageSnapshot());
     return img ? img->encode() : nullptr;
@@ -87,8 +111,18 @@ static SkData* encode_snapshot(const sk_sp<SkSurface>& surface) {
     static sk_sp<GrContext> create_grcontext() { return nullptr; }
 #endif
 
+
+
 int main() {
-    const DrawOptions options = GetDrawOptions();
+    DrawOptions options = GetDrawOptions();
+    // If textOnly then only do one type of image, otherwise the text
+    // output is duplicated for each type.
+    if (options.textOnly) {
+        options.raster = true;
+        options.gpu = false;
+        options.pdf = false;
+        options.skp = false;
+    }
     if (options.source) {
         sk_sp<SkData> data(SkData::MakeFromFileName(options.source));
         if (!data) {
@@ -158,12 +192,14 @@ int main() {
         picture->serialize(&skpStream);
         skpData = skpStream.detachAsData();
     }
+    bool textOnly = options.textOnly;
 
     printf("{\n");
-    dump_output(rasterData, "Raster", !gpuData && !pdfData && !skpData);
-    dump_output(gpuData, "Gpu", !pdfData && !skpData);
-    dump_output(pdfData, "Pdf", !skpData);
-    dump_output(skpData, "Skp");
+    dump_output(rasterData, "Raster", !gpuData && !pdfData && !skpData && !textOnly);
+    dump_output(gpuData, "Gpu", !pdfData && !skpData && !textOnly);
+    dump_output(pdfData, "Pdf", !skpData && !textOnly);
+    dump_output(skpData, "Skp", !textOnly);
+    dump_text(textoutput, "Text");
     printf("}\n");
 
     return 0;

tools/fiddle/fiddle_main.h

@@ -24,7 +24,7 @@ extern SkBitmap source;
 extern sk_sp<SkImage> image;
 
 struct DrawOptions {
-    DrawOptions(int w, int h, bool r, bool g, bool p, bool k, bool srgb, bool f16, const char* s)
+    DrawOptions(int w, int h, bool r, bool g, bool p, bool k, bool srgb, bool f16, bool textOnly, const char* s)
         : size(SkISize::Make(w, h))
         , raster(r)
         , gpu(g)
@@ -32,6 +32,7 @@ struct DrawOptions {
         , skp(k)
         , srgb(srgb)
         , f16(f16)
+        , textOnly(textOnly)
         , source(s)
     {
         // F16 mode is only valid for color correct backends.
@@ -44,10 +45,12 @@ struct DrawOptions {
     bool skp;
     bool srgb;
     bool f16;
+    bool textOnly;
     const char* source;
 };
 
 extern DrawOptions GetDrawOptions();
+extern void SkDebugf(const char * format, ...);
 extern void draw(SkCanvas*);
 
 #endif  // fiddle_main_DEFINED