Example: Add masks to layers

This example covers creation of a LayeredFile (A Photoshop file) as well as that of an image layer while adding a pixel mask channel to said layer.

Relevant documentation links:

• psapi.Layer_8bit

• Layer

C++

/*
Example of creating a simple document with a single layer and a mask using the PhotoshopAPI.
*/

#include "PhotoshopAPI.h"

#include <unordered_map>
#include <vector>


int main()
{
	using namespace NAMESPACE_PSAPI;

	// Initialize some constants that we will need throughout the program
	constexpr uint32_t width = 64u;
	constexpr uint32_t height = 64u;

	// Create an 8-bit LayeredFile as our starting point, 8- 16- and 32-bit are fully supported
	LayeredFile<bpp8_t> document = { Enum::ColorMode::RGB, width, height };
	// Create our individual channels to add to our image layer. Keep in mind that all these 3 channels need to 
	// be specified for RGB mode
	std::unordered_map <Enum::ChannelID, std::vector<bpp8_t>> channel_map;
	channel_map[Enum::ChannelID::Red] = std::vector<bpp8_t>(width * height, 255u);
	channel_map[Enum::ChannelID::Green] = std::vector<bpp8_t>(width * height, 0u);
	channel_map[Enum::ChannelID::Blue] = std::vector<bpp8_t>(width * height, 0u);

	// Create a mask channel which for now is just a semi grey channel. This channel for the time being
	// needs to be the exact same size as the layer even though Photoshop officially supports masks being smaller
	// or larger than channels
	auto maskchannel = std::vector<bpp8_t>(width * height, 128u);

	ImageLayer<bpp8_t>::Params layer_params = {};
	layer_params.name = "Layer Red";
	layer_params.width = width;
	layer_params.height = height;
	layer_params.mask = maskchannel;
	layer_params.center_x = 32;
	layer_params.center_y = 32;

	auto layer = std::make_shared<ImageLayer<bpp8_t>>(
		std::move(channel_map),
		layer_params
	);

	document.add_layer(layer);

	// Convert to PhotoshopDocument and write to disk. Note that from this point onwards 
	// our LayeredFile instance is no longer usable
	LayeredFile<bpp8_t>::write(std::move(document), "WriteLayerMasks.psd");
}

Python

# Example of creating a simple document with a single layer and a mask using the PhotoshopAPI.
import os
import numpy as np
import photoshopapi as psapi


def main() -> None:
    # Initialize some constants that we will need throughout the program
    width = 64
    height = 64
    
    color_mode = psapi.enum.ColorMode.rgb

    # Generate our LayeredFile instance
    document = psapi.LayeredFile_8bit(color_mode, width, height)

    img_data = np.zeros((3, height, width), np.uint8)
    img_data[0] = 255
    mask = np.full((height, width), 128, np.uint8)

    img_layer = psapi.ImageLayer_8bit(img_data, "Layer Red", layer_mask=mask, width=width, height=height)

    # Add the layer and write to disk
    document.add_layer(img_layer)
    document.write(os.path.join(os.path.dirname(__file__), "WriteLayerMasks.psd"))


if __name__ == "__main__":
    main()