Smallest possible desktop application that uses Skia to render stuff.

helloskia/HelloSkia.cpp

Index: helloskia/HelloSkia.cpp
diff --git a/helloskia/HelloSkia.cpp b/helloskia/HelloSkia.cpp
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+/*
+ * Copyright 2013 Google Inc.
+ *
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ */
+
+#include "HelloSkia.h"
+
+#include "SkGraphics.h"
+#include "SkDraw.h"
+
+#if HELLOSKIA_USE_GPU

[caryclark, 2013/06/03 19:02:01]

does the GPU version work yet?

[sglez, 2013/06/03 20:24:07]

No, I'm posting the software version for review before implementing that.

+/*
+#include "gl/GrGLInterface.h"
+#include "gl/GrGLUtil.h"
+*/

[caryclark, 2013/06/03 19:02:01]

Why commented out? If this documentation, include a comment as to why it's here
*/

[sglez, 2013/06/03 20:24:07]

This shouldn't be here, sorry about that.

+#include "GrRenderTarget.h"
+#include "GrContext.h"
+#include "SkGpuDevice.h"
+#endif
+
+SkOSWindow* create_sk_window(void* hwnd, int argc, char** argv) {

[caryclark, 2013/06/03 19:02:01]

static

[sglez, 2013/06/03 20:24:07]

These three functions need outside visibility since they are called from
skia_unix.cpp and skia_mac.cpp

[caryclark, 2013/06/04 11:48:12]

Yes, you're right. I forgot the historic naming convention. In more recent code
xxx_xxx function names are local and therefore static. These functions,
application_init and application_term, got named before that convention was
solidified.

On 2013/06/03 20:24:07, sglez wrote:

+    return new HelloWindow(hwnd, argc, argv);
+}
+
+void application_init() {
+#ifdef SK_BUILD_FOR_MAC

[caryclark, 2013/06/03 19:02:01]

I assume this is if SK_BUILD_FOR_ANDROID

[sglez, 2013/06/03 20:24:07]

I had copied this from SampleApp. 

I just now deleted this check, since I assume that HelloSkia will always be a
Desktop app. SampleApp still looks like this, though

+    setenv("ANDROID_ROOT", "/android/device/data", 0);
+#endif
+    SkGraphics::Init();
+    SkEvent::Init();
+}
+
+void application_term() {
+    SkEvent::Term();
+    SkGraphics::Term();
+}
+
+HelloWindow::HelloWindow(void* hWnd, int argc, char** argv)
+    : INHERITED(hWnd)
+{
+    this->setConfig(SkBitmap::kARGB_8888_Config);
+    this->setVisibleP(true);
+    this->setClipToBounds(false);
+
+    fBGColor = 0xffffffff;

[caryclark, 2013/06/03 19:02:01]

Use SK_ColorWHITE

[sglez, 2013/06/03 20:24:07]

Done.

+    fRotationAngle = 0.0;

[caryclark, 2013/06/03 19:02:01]

Declare fRotationAngle as an SkScalar (if you have not done so already) then use
SkIntToScalar(#) to make the scalars floats or (in the future) doubles

[sglez, 2013/06/03 20:24:08]

Done.

+}
+
+void HelloWindow::draw(SkCanvas* canvas) {
+    // Clear background
+    canvas->drawColor(fBGColor);
+
+    SkPaint paint;
+    paint.setColor(0xff0000ff);  // SkColor is ARGB
+

[caryclark, 2013/06/03 19:02:01]

Use SK_ColorBLUE etc

[sglez, 2013/06/03 20:24:08]

Done.

+    // Draw a rectangle with blue paint
+    SkRect rect = {10, 10, 128, 128};
+    canvas->drawRect(rect, paint);

[caryclark, 2013/06/03 19:02:01]

I assume you wanted to draw the rect aliased

[sglez, 2013/06/03 20:24:08]

Yes, it was intentional.

+
+    // Draw a circle with anti aliased red paint
+    paint.setFlags(SkPaint::kAntiAlias_Flag);
+    paint.setColor(0xff00ff00);
+
+    canvas->drawCircle(200,200,64,paint);

[caryclark, 2013/06/03 19:02:01]

put spaces after the commas (to be consistent with your SkRect initialization)

[sglez, 2013/06/03 20:24:08]

Done.

+
+    // Draw a message with a nice paint.
+    paint.setFlags(
+            SkPaint::kAntiAlias_Flag |
+            SkPaint::kUnderlineText_Flag |
+            SkPaint::kSubpixelText_Flag /* Do this to avoid waggly text when rotating. */);
+    paint.setColor(0xff000000);
+    paint.setTextSize(SkIntToScalar(20));

[caryclark, 2013/06/03 19:02:01]

Consider bracketing all SkScalars like this

+
+    canvas->save();
+    static const char message[] = "Hello Skia!!!";
+    canvas->translate(300, 300);
+    fRotationAngle += 0.2;

[caryclark, 2013/06/03 19:02:01]

You can use SkFloatToScalar here

[sglez, 2013/06/03 20:24:08]

Done.

+    if (fRotationAngle > 360.0) {
+        fRotationAngle -= 360.0;
+    }
+    canvas->rotate(fRotationAngle);
+    canvas->drawText(message, strlen(message), 0, 0, paint);
+    canvas->restore();
+    this->inval(NULL);
+}
+