1 /*
2 * Copyright 2017 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "example/HelloWorld.h"
9
10 #include "include/core/SkCanvas.h"
11 #include "include/core/SkFont.h"
12 #include "include/core/SkGraphics.h"
13 #include "include/core/SkSurface.h"
14 #include "include/effects/SkGradientShader.h"
15
16 using namespace sk_app;
17
Create(int argc,char ** argv,void * platformData)18 Application* Application::Create(int argc, char** argv, void* platformData) {
19 return new HelloWorld(argc, argv, platformData);
20 }
21
HelloWorld(int argc,char ** argv,void * platformData)22 HelloWorld::HelloWorld(int argc, char** argv, void* platformData)
23 : fBackendType(Window::kNativeGL_BackendType)
24 , fRotationAngle(0) {
25 SkGraphics::Init();
26
27 fWindow = Window::CreateNativeWindow(platformData);
28 fWindow->setRequestedDisplayParams(DisplayParams());
29
30 // register callbacks
31 fWindow->pushLayer(this);
32
33 fWindow->attach(fBackendType);
34 }
35
~HelloWorld()36 HelloWorld::~HelloWorld() {
37 fWindow->detach();
38 delete fWindow;
39 }
40
updateTitle()41 void HelloWorld::updateTitle() {
42 if (!fWindow || fWindow->sampleCount() <= 1) {
43 return;
44 }
45
46 SkString title("Hello World ");
47 title.append(Window::kRaster_BackendType == fBackendType ? "Raster" : "OpenGL");
48 fWindow->setTitle(title.c_str());
49 }
50
onBackendCreated()51 void HelloWorld::onBackendCreated() {
52 this->updateTitle();
53 fWindow->show();
54 fWindow->inval();
55 }
56
onPaint(SkSurface * surface)57 void HelloWorld::onPaint(SkSurface* surface) {
58 auto canvas = surface->getCanvas();
59
60 // Clear background
61 canvas->clear(SK_ColorWHITE);
62
63 SkPaint paint;
64 paint.setColor(SK_ColorRED);
65
66 // Draw a rectangle with red paint
67 SkRect rect = SkRect::MakeXYWH(10, 10, 128, 128);
68 canvas->drawRect(rect, paint);
69
70 // Set up a linear gradient and draw a circle
71 {
72 SkPoint linearPoints[] = { { 0, 0 }, { 300, 300 } };
73 SkColor linearColors[] = { SK_ColorGREEN, SK_ColorBLACK };
74 paint.setShader(SkGradientShader::MakeLinear(linearPoints, linearColors, nullptr, 2,
75 SkTileMode::kMirror));
76 paint.setAntiAlias(true);
77
78 canvas->drawCircle(200, 200, 64, paint);
79
80 // Detach shader
81 paint.setShader(nullptr);
82 }
83
84 // Draw a message with a nice black paint
85 SkFont font;
86 font.setSubpixel(true);
87 font.setSize(20);
88 paint.setColor(SK_ColorBLACK);
89
90 canvas->save();
91 static const char message[] = "Hello World";
92
93 // Translate and rotate
94 canvas->translate(300, 300);
95 fRotationAngle += 0.2f;
96 if (fRotationAngle > 360) {
97 fRotationAngle -= 360;
98 }
99 canvas->rotate(fRotationAngle);
100
101 // Draw the text
102 canvas->drawSimpleText(message, strlen(message), SkTextEncoding::kUTF8, 0, 0, font, paint);
103
104 canvas->restore();
105 }
106
onIdle()107 void HelloWorld::onIdle() {
108 // Just re-paint continously
109 fWindow->inval();
110 }
111
onChar(SkUnichar c,skui::ModifierKey modifiers)112 bool HelloWorld::onChar(SkUnichar c, skui::ModifierKey modifiers) {
113 if (' ' == c) {
114 fBackendType = Window::kRaster_BackendType == fBackendType ? Window::kNativeGL_BackendType
115 : Window::kRaster_BackendType;
116 fWindow->detach();
117 fWindow->attach(fBackendType);
118 }
119 return true;
120 }
121