Crop.cpp

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// Copyright (c) 2008-2019 OpenShot Studios, LLC
//
// SPDX-License-Identifier: LGPL-3.0-or-later
 
#include "Crop.h"
#include "Exceptions.h"
#include "KeyFrame.h"
 
#include <QImage>
#include <QPainter>
#include <QRectF>
#include <QRect>
#include <QSize>
 
using namespace openshot;

Crop::Crop() : Crop::Crop(0.0, 0.0, 0.0, 0.0, 0.0, 0.0) {}
 
Crop::Crop(
    Keyframe left, Keyframe top,
    Keyframe right, Keyframe bottom,
    Keyframe x, Keyframe y) :
        left(left), top(top), right(right), bottom(bottom), x(x), y(y), resize(false)
{
    // Init effect properties
    init_effect_details();
}
 
// Init effect settings
void Crop::init_effect_details()
{
    InitEffectInfo();

    info.class_name = "Crop";
    info.name = "Crop";
    info.description = "Crop out any part of your video.";
    info.has_audio = false;
    info.has_video = true;
}
 
// This method is required for all derived classes of EffectBase, and returns a
// modified openshot::Frame object
std::shared_ptr<openshot::Frame> Crop::GetFrame(std::shared_ptr<openshot::Frame> frame, int64_t frame_number)
{
    // Get the frame's image
    std::shared_ptr<QImage> frame_image = frame->GetImage();
 
    // Get current keyframe values
    double left_value = left.GetValue(frame_number);
    double top_value = top.GetValue(frame_number);
    double right_value = right.GetValue(frame_number);
    double bottom_value = bottom.GetValue(frame_number);
 
    // Get the current shift amount
    double x_shift = x.GetValue(frame_number);
    double y_shift = y.GetValue(frame_number);
 
    QSize sz = frame_image->size();
 
    // Compute destination rectangle to paint into
    QRectF paint_r(
            left_value * sz.width(), top_value * sz.height(),
            std::max(0.0, 1.0 - left_value - right_value) * sz.width(),
            std::max(0.0, 1.0 - top_value - bottom_value) * sz.height());
 
    // Copy rectangle is destination translated by offsets
    QRectF copy_r = paint_r;
    copy_r.translate(x_shift * sz.width(), y_shift * sz.height());
 
    // Constrain offset copy rect to stay within image borders
    if (copy_r.left() < 0) {
        paint_r.setLeft(paint_r.left() - copy_r.left());
        copy_r.setLeft(0);
    }
    if (copy_r.right() > sz.width()) {
        paint_r.setRight(paint_r.right() - (copy_r.right() - sz.width()));
        copy_r.setRight(sz.width());
    }
    if (copy_r.top() < 0) {
        paint_r.setTop(paint_r.top() - copy_r.top());
        copy_r.setTop(0);
    }
    if (copy_r.bottom() > sz.height()) {
        paint_r.setBottom(paint_r.bottom() - (copy_r.bottom() - sz.height()));
        copy_r.setBottom(sz.height());
    }
 
    QImage cropped(sz, QImage::Format_RGBA8888_Premultiplied);
    cropped.fill(Qt::transparent);
 
    QPainter p(&cropped);
    p.drawImage(paint_r, *frame_image, copy_r);
    p.end();
 
    if (resize) {
        // Resize image to match cropped QRect (reduce frame size)
        frame->AddImage(std::make_shared<QImage>(cropped.copy(paint_r.toRect())));
    } else {
        // Copy cropped image into transparent frame image (maintain frame size)
        frame->AddImage(std::make_shared<QImage>(cropped.copy()));
    }
 
    // return the modified frame
    return frame;
}
 
// Generate JSON string of this object
std::string Crop::Json() const {
 
    // Return formatted string
    return JsonValue().toStyledString();
}
 
// Generate Json::Value for this object
Json::Value Crop::JsonValue() const {
 
    // Create root json object
    Json::Value root = EffectBase::JsonValue(); // get parent properties
    root["type"] = info.class_name;
    root["left"] = left.JsonValue();
    root["top"] = top.JsonValue();
    root["right"] = right.JsonValue();
    root["bottom"] = bottom.JsonValue();
    root["x"] = x.JsonValue();
    root["y"] = y.JsonValue();
    root["resize"] = resize;
 
    // return JsonValue
    return root;
}
 
// Load JSON string into this object
void Crop::SetJson(const std::string value) {
 
    // Parse JSON string into JSON objects
    try
    {
        const Json::Value root = openshot::stringToJson(value);
        // Set all values that match
        SetJsonValue(root);
    }
    catch (const std::exception& e)
    {
        // Error parsing JSON (or missing keys)
        throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
    }
}
 
// Load Json::Value into this object
void Crop::SetJsonValue(const Json::Value root) {
 
    // Set parent data
    EffectBase::SetJsonValue(root);
 
    // Set data from Json (if key is found)
    if (!root["left"].isNull())
        left.SetJsonValue(root["left"]);
    if (!root["top"].isNull())
        top.SetJsonValue(root["top"]);
    if (!root["right"].isNull())
        right.SetJsonValue(root["right"]);
    if (!root["bottom"].isNull())
        bottom.SetJsonValue(root["bottom"]);
    if (!root["x"].isNull())
        x.SetJsonValue(root["x"]);
    if (!root["y"].isNull())
        y.SetJsonValue(root["y"]);
    if (!root["resize"].isNull())
        resize = root["resize"].asBool();
}
 
// Get all properties for a specific frame
std::string Crop::PropertiesJSON(int64_t requested_frame) const {
 
    // Generate JSON properties list
    Json::Value root = BasePropertiesJSON(requested_frame);
 
    // Keyframes
    root["left"] = add_property_json("Left Size", left.GetValue(requested_frame), "float", "", &left, 0.0, 1.0, false, requested_frame);
    root["top"] = add_property_json("Top Size", top.GetValue(requested_frame), "float", "", &top, 0.0, 1.0, false, requested_frame);
    root["right"] = add_property_json("Right Size", right.GetValue(requested_frame), "float", "", &right, 0.0, 1.0, false, requested_frame);
    root["bottom"] = add_property_json("Bottom Size", bottom.GetValue(requested_frame), "float", "", &bottom, 0.0, 1.0, false, requested_frame);
    root["x"] = add_property_json("X Offset", x.GetValue(requested_frame), "float", "", &x, -1.0, 1.0, false, requested_frame);
    root["y"] = add_property_json("Y Offset", y.GetValue(requested_frame), "float", "", &y, -1.0, 1.0, false, requested_frame);
 
    // Add replace_image choices (dropdown style)
    root["resize"] = add_property_json("Resize Image", resize, "int", "", NULL, 0, 1, false, requested_frame);
    root["resize"]["choices"].append(add_property_choice_json("Yes", true, resize));
    root["resize"]["choices"].append(add_property_choice_json("No", false, resize));
 
    // Return formatted string
    return root.toStyledString();
}