Shift.cpp

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// Copyright (c) 2008-2019 OpenShot Studios, LLC
//
// SPDX-License-Identifier: LGPL-3.0-or-later
 
#include "Shift.h"
#include "Exceptions.h"
 
using namespace openshot;
 
Shift::Shift() : x(0.0), y(0.0) {
    // Init effect properties
    init_effect_details();
}
 
// Default constructor
Shift::Shift(Keyframe x, Keyframe y) : x(x), y(y)
{
    // Init effect properties
    init_effect_details();
}
 
// Init effect settings
void Shift::init_effect_details()
{
    InitEffectInfo();
 
    info.class_name = "Shift";
    info.name = "Shift";
    info.description = "Shift the image up, down, left, and right (with infinite wrapping).";
    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> Shift::GetFrame(std::shared_ptr<openshot::Frame> frame, int64_t frame_number)
{
    // Get the frame's image
    std::shared_ptr<QImage> frame_image = frame->GetImage();
    unsigned char *pixels = (unsigned char *) frame_image->bits();
 
    // Get the current shift amount, and clamp to range (-1 to 1 range)
    double x_shift = x.GetValue(frame_number);
    double x_shift_limit = fmod(fabs(x_shift), 1.0);
    double y_shift = y.GetValue(frame_number);
    double y_shift_limit = fmod(fabs(y_shift), 1.0);
 
    // Declare temp arrays to hold pixels while we move things around
    unsigned char *temp_row = new unsigned char[frame_image->width() * 4]();
 
    // X-SHIFT
    // Loop through rows
    for (int row = 0; row < frame_image->height(); row++) {
        // Copy current row's pixels
        int starting_row_pixel = row * frame_image->width();
        memcpy(temp_row, &pixels[starting_row_pixel * 4], sizeof(char) * frame_image->width() * 4);
 
        // Replace current row with left part of the pixels
        if (x_shift > 0.0) {
            // Move left side to the right
            int relative_pixel_start = (int)round(frame_image->width() * x_shift_limit);
            memcpy(&pixels[(starting_row_pixel + relative_pixel_start) * 4], &temp_row[0], sizeof(char) * (frame_image->width() - relative_pixel_start) * 4);
 
            // Move right side to the left
            memcpy(&pixels[starting_row_pixel * 4], &temp_row[(frame_image->width() - relative_pixel_start) * 4], sizeof(char) * relative_pixel_start * 4);
        } else if (x_shift < 0.0) {
            // Move right side to the left
            int relative_pixel_start = (int)round(frame_image->width() * x_shift_limit);
            memcpy(&pixels[starting_row_pixel * 4], &temp_row[relative_pixel_start * 4], sizeof(char) * (frame_image->width() - relative_pixel_start) * 4);
 
            // Move left side to the right
            memcpy(&pixels[(starting_row_pixel + (frame_image->width() - relative_pixel_start)) * 4], &temp_row[0], sizeof(char) * relative_pixel_start * 4);
        }
    }
 
    // Make temp copy of pixels for Y-SHIFT
    unsigned char *temp_image = new unsigned char[frame_image->width() * frame_image->height() * 4]();
    memcpy(temp_image, pixels, sizeof(char) * frame_image->width() * frame_image->height() * 4);
 
    // Y-SHIFT
    // Replace current row with left part of the pixels
    if (y_shift > 0.0) {
        // Move top side to bottom
        int relative_pixel_start = frame_image->width() * (int)round(frame_image->height() * y_shift_limit);
        memcpy(&pixels[relative_pixel_start * 4], temp_image, sizeof(char) * ((frame_image->width() * frame_image->height()) - relative_pixel_start) * 4);
 
        // Move bottom side to top
        memcpy(pixels, &temp_image[((frame_image->width() * frame_image->height()) - relative_pixel_start) * 4], sizeof(char) * relative_pixel_start * 4);
 
    } else if (y_shift < 0.0) {
        // Move bottom side to top
        int relative_pixel_start = frame_image->width() * (int)round(frame_image->height() * y_shift_limit);
        memcpy(pixels, &temp_image[relative_pixel_start * 4], sizeof(char) * ((frame_image->width() * frame_image->height()) - relative_pixel_start) * 4);
 
        // Move left side to the right
        memcpy(&pixels[((frame_image->width() * frame_image->height()) - relative_pixel_start) * 4], temp_image, sizeof(char) * relative_pixel_start * 4);
    }
 
    // Delete arrays
    delete[] temp_row;
    delete[] temp_image;
 
    // return the modified frame
    return frame;
}
 
// Generate JSON string of this object
std::string Shift::Json() const {
 
    // Return formatted string
    return JsonValue().toStyledString();
}
 
// Generate Json::Value for this object
Json::Value Shift::JsonValue() const {
 
    // Create root json object
    Json::Value root = EffectBase::JsonValue(); // get parent properties
    root["type"] = info.class_name;
    root["x"] = x.JsonValue();
    root["y"] = y.JsonValue();
 
    // return JsonValue
    return root;
}
 
// Load JSON string into this object
void Shift::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 Shift::SetJsonValue(const Json::Value root) {
 
    // Set parent data
    EffectBase::SetJsonValue(root);
 
    // Set data from Json (if key is found)
    if (!root["x"].isNull())
        x.SetJsonValue(root["x"]);
    if (!root["y"].isNull())
        y.SetJsonValue(root["y"]);
}
 
// Get all properties for a specific frame
std::string Shift::PropertiesJSON(int64_t requested_frame) const {
 
    // Generate JSON properties list
    Json::Value root = BasePropertiesJSON(requested_frame);
 
    // Keyframes
    root["x"] = add_property_json("X Shift", x.GetValue(requested_frame), "float", "", &x, -1, 1, false, requested_frame);
    root["y"] = add_property_json("Y Shift", y.GetValue(requested_frame), "float", "", &y, -1, 1, false, requested_frame);
 
    // Return formatted string
    return root.toStyledString();
}