skia2/example/HelloWorld.cpp
Brian Osman 80fc07e8f8 Create a Window::Layer interface to reduce sk_app glue code
This also makes it possible to manage other parts of viewer, etc (like
the stats screen, command set, even samples) as additional layers in the
stack. For now, it just removes a lot of boilerplate.

Bug: skia:
Change-Id: Ic2f80690fc76c683b3736287dc2b738c50d38614
Reviewed-on: https://skia-review.googlesource.com/82688
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2017-12-11 16:46:58 +00:00

117 lines
3.0 KiB
C++

/*
* Copyright 2017 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "HelloWorld.h"
#include "GrContext.h"
#include "SkCanvas.h"
#include "SkGradientShader.h"
#include "SkGraphics.h"
using namespace sk_app;
Application* Application::Create(int argc, char** argv, void* platformData) {
return new HelloWorld(argc, argv, platformData);
}
HelloWorld::HelloWorld(int argc, char** argv, void* platformData)
: fBackendType(Window::kNativeGL_BackendType)
, fRotationAngle(0) {
SkGraphics::Init();
fWindow = Window::CreateNativeWindow(platformData);
fWindow->setRequestedDisplayParams(DisplayParams());
// register callbacks
fWindow->pushLayer(this);
fWindow->attach(fBackendType);
}
HelloWorld::~HelloWorld() {
fWindow->detach();
delete fWindow;
}
void HelloWorld::updateTitle() {
if (!fWindow || fWindow->sampleCount() < 0) {
return;
}
SkString title("Hello World ");
title.append(Window::kRaster_BackendType == fBackendType ? "Raster" : "OpenGL");
fWindow->setTitle(title.c_str());
}
void HelloWorld::onBackendCreated() {
this->updateTitle();
fWindow->show();
fWindow->inval();
}
void HelloWorld::onPaint(SkCanvas* canvas) {
// Clear background
canvas->clear(SK_ColorWHITE);
SkPaint paint;
paint.setColor(SK_ColorRED);
// Draw a rectangle with red paint
SkRect rect = SkRect::MakeXYWH(10, 10, 128, 128);
canvas->drawRect(rect, paint);
// Set up a linear gradient and draw a circle
{
SkPoint linearPoints[] = { { 0, 0 }, { 300, 300 } };
SkColor linearColors[] = { SK_ColorGREEN, SK_ColorBLACK };
paint.setShader(SkGradientShader::MakeLinear(linearPoints, linearColors, nullptr, 2,
SkShader::kMirror_TileMode));
paint.setAntiAlias(true);
canvas->drawCircle(200, 200, 64, paint);
// Detach shader
paint.setShader(nullptr);
}
// Draw a message with a nice black paint
paint.setSubpixelText(true);
paint.setColor(SK_ColorBLACK);
paint.setTextSize(20);
canvas->save();
static const char message[] = "Hello World";
// Translate and rotate
canvas->translate(300, 300);
fRotationAngle += 0.2f;
if (fRotationAngle > 360) {
fRotationAngle -= 360;
}
canvas->rotate(fRotationAngle);
// Draw the text
canvas->drawText(message, strlen(message), 0, 0, paint);
canvas->restore();
}
void HelloWorld::onIdle() {
// Just re-paint continously
fWindow->inval();
}
bool HelloWorld::onChar(SkUnichar c, uint32_t modifiers) {
if (' ' == c) {
fBackendType = Window::kRaster_BackendType == fBackendType ? Window::kNativeGL_BackendType
: Window::kRaster_BackendType;
fWindow->detach();
fWindow->attach(fBackendType);
}
return true;
}