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author | Zeno Albisser <zeno.albisser@digia.com> | 2013-08-15 21:46:11 +0200 |
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committer | Zeno Albisser <zeno.albisser@digia.com> | 2013-08-15 21:46:11 +0200 |
commit | 679147eead574d186ebf3069647b4c23e8ccace6 (patch) | |
tree | fc247a0ac8ff119f7c8550879ebb6d3dd8d1ff69 /chromium/ppapi/examples/2d/paint_manager_example.cc | |
download | qtwebengine-chromium-679147eead574d186ebf3069647b4c23e8ccace6.tar.gz |
Initial import.
Diffstat (limited to 'chromium/ppapi/examples/2d/paint_manager_example.cc')
-rw-r--r-- | chromium/ppapi/examples/2d/paint_manager_example.cc | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/chromium/ppapi/examples/2d/paint_manager_example.cc b/chromium/ppapi/examples/2d/paint_manager_example.cc new file mode 100644 index 00000000000..86bdbe79ed8 --- /dev/null +++ b/chromium/ppapi/examples/2d/paint_manager_example.cc @@ -0,0 +1,161 @@ +// Copyright (c) 2011 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "ppapi/c/pp_input_event.h" +#include "ppapi/cpp/graphics_2d.h" +#include "ppapi/cpp/image_data.h" +#include "ppapi/cpp/input_event.h" +#include "ppapi/cpp/instance.h" +#include "ppapi/cpp/module.h" +#include "ppapi/cpp/size.h" +#include "ppapi/cpp/view.h" +#include "ppapi/utility/graphics/paint_manager.h" + +// Number of pixels to each side of the center of the square that we draw. +static const int kSquareRadius = 2; + +// We identify our square by the center point. This computes the rect for the +// square given that point. +pp::Rect SquareForPoint(int x, int y) { + return PP_MakeRectFromXYWH(x - kSquareRadius, y - kSquareRadius, + kSquareRadius * 2 + 1, kSquareRadius * 2 + 1); +} + +static void FillRect(pp::ImageData* image, + int left, int top, int width, int height, + uint32_t color) { + for (int y = std::max(0, top); + y < std::min(image->size().height() - 1, top + height); + y++) { + for (int x = std::max(0, left); + x < std::min(image->size().width() - 1, left + width); + x++) + *image->GetAddr32(pp::Point(x, y)) = color; + } +} + +class MyInstance : public pp::Instance, public pp::PaintManager::Client { + public: + MyInstance(PP_Instance instance) + : pp::Instance(instance), + paint_manager_(), + last_x_(0), + last_y_(0) { + paint_manager_.Initialize(this, this, false); + RequestInputEvents(PP_INPUTEVENT_CLASS_MOUSE); + } + + virtual bool HandleInputEvent(const pp::InputEvent& event) { + switch (event.GetType()) { + case PP_INPUTEVENT_TYPE_MOUSEDOWN: { + pp::MouseInputEvent mouse_event(event); + // Update the square on a mouse down. + if (mouse_event.GetButton() == PP_INPUTEVENT_MOUSEBUTTON_LEFT) { + UpdateSquare(static_cast<int>(mouse_event.GetPosition().x()), + static_cast<int>(mouse_event.GetPosition().y())); + } + return true; + } + case PP_INPUTEVENT_TYPE_MOUSEMOVE: { + pp::MouseInputEvent mouse_event(event); + // Update the square on a drag. + if (mouse_event.GetButton() == PP_INPUTEVENT_MOUSEBUTTON_LEFT) { + UpdateSquare(static_cast<int>(mouse_event.GetPosition().x()), + static_cast<int>(mouse_event.GetPosition().y())); + } + return true; + } + default: + return false; + } + } + + virtual void DidChangeView(const pp::View& view) { + paint_manager_.SetSize(view.GetRect().size()); + } + + // PaintManager::Client implementation. + virtual bool OnPaint(pp::Graphics2D& graphics_2d, + const std::vector<pp::Rect>& paint_rects, + const pp::Rect& paint_bounds) { + // Make an image just large enough to hold all dirty rects. We won't + // actually paint all of these pixels below, but rather just the dirty + // ones. Since image allocation can be somewhat heavyweight, we wouldn't + // want to allocate separate images in the case of multiple dirty rects. + pp::ImageData updated_image(this, PP_IMAGEDATAFORMAT_BGRA_PREMUL, + paint_bounds.size(), false); + + // We could repaint everything inside the image we made above. For this + // example, that would probably be the easiest thing since updates are + // small and typically close to each other. However, for the purposes of + // demonstration, here we only actually paint the pixels that changed, + // which may be the entire update region, or could be multiple discontigous + // regions inside the update region. + // + // Note that the aggregator used by the paint manager won't give us + // multiple regions that overlap, so we don't have to worry about double + // painting in this code. + for (size_t i = 0; i < paint_rects.size(); i++) { + // Since our image is just the invalid region, we need to offset the + // areas we paint by that much. This is just a light blue background. + FillRect(&updated_image, + paint_rects[i].x() - paint_bounds.x(), + paint_rects[i].y() - paint_bounds.y(), + paint_rects[i].width(), + paint_rects[i].height(), + 0xFFAAAAFF); + } + + // Paint the square black. Because we're lazy, we do this outside of the + // loop above. + pp::Rect square = SquareForPoint(last_x_, last_y_); + FillRect(&updated_image, + square.x() - paint_bounds.x(), + square.y() - paint_bounds.y(), + square.width(), + square.height(), + 0xFF000000); + + graphics_2d.PaintImageData(updated_image, paint_bounds.point()); + return true; + } + + private: + void UpdateSquare(int x, int y) { + if (x == last_x_ && y == last_y_) + return; // Nothing changed. + + // Invalidate the region around the old square which needs to be repainted + // because it's no longer there. + paint_manager_.InvalidateRect(SquareForPoint(last_x_, last_y_)); + + // Update the current position. + last_x_ = x; + last_y_ = y; + + // Also invalidate the region around the new square. + paint_manager_.InvalidateRect(SquareForPoint(last_x_, last_y_)); + } + + pp::PaintManager paint_manager_; + + int last_x_; + int last_y_; +}; + +class MyModule : public pp::Module { + public: + virtual pp::Instance* CreateInstance(PP_Instance instance) { + return new MyInstance(instance); + } +}; + +namespace pp { + +// Factory function for your specialization of the Module object. +Module* CreateModule() { + return new MyModule(); +} + +} // namespace pp |