Cappy

A cross plateform screen capping tool that lets you immediately explore the pixels on your monitor screen(s).

Features

• Smooth panning and precise zooming of the captured screen(s).
• Inspect pixel data of the currently hovered pixel, then copy that data to the clipboard.
• Crop out sections and/or save the capture to a PNG.
• A grid mode to better see the nice pixels.
• A flashlight mode!

Demo

This demo is heavily compressed to save space. When you run the application it will run smoother and be at your native resolution. :)

Supported Platforms

• Linux
• Windows

Build

Cappy is built using CMake. CMake will take care of downloading all necessary dependencies. It may take a while to build because everything is built from scratch and statically linked. In some cases you may need to install libx11-dev on Linux with sudo apt-get install libx11-dev.

cmake -S . -B build -DCMAKE_BUILD_TYPE=Release  # or Debug for debug build
cmake --build build

The compiled executable will be stored in ./build/release/bin/cappy for release, and ./build/debug/bin/cappy for debug. Since this program is statically linked, there is no external dependencies and it can be stored anywhere on your PC. You can use the install command to move it to an appropriate folder on your OS.

Install

cd build
cmake --install .

Setting global shortcut

Cappy is best used with a global keyboard shortcut so it can be launched any time you need it. The way to do this depends on the OS. Find the path to the executable.

Setting shortcut for Ubuntu

1. Open the Activities overview and start typing Settings.
2. Click on Settings.
3. Click Keyboard in the sidebar to open the panel.
4. In the Keyboard Shortcuts section, select View and Customize Shortcuts.
5. Add a keyboard shortcut by clicking the + button towards the bottom of the list.
6. Set the Name to Cappy.
7. Set the Command to the path of the executable.
8. Set the shortcut to whatever you'd like. I like using ctrl+left_shift+z.

Setting shortcut for Windows 10/11 (Way 1)

1. Right-click the blank area on the desktop and select New -> Shortcut. Type the location of the item and click Next. If you don’t know the path of the app, you can click the Browse button. Then you can select the target app’s executable file and click OK. Type a name for the shortcut and click Finish to create a shortcut for the app.
2. Then you can right-click the app’s shortcut and select Properties.
3. In the Properties window, you can click the Shortcut tab.
4. Next to the Shortcut key field, you can set a keyboard shortcut that you want to use to open the app. Click OK to save the setting.

Setting shortcut for Windows 10/11 (Way 2)

1. You can click Start Menu on your Windows 10 computer. For Windows 11, you need to click the All apps icon to view all apps in the Start Menu.
2. Next, you can scroll down to find the target app. Right-click the app and select Pin to taskbar or More -> Pin to taskbar to add the program to the Windows taskbar. Alternatively, you can also directly drag the app onto the taskbar to pin the program to the taskbar. You can follow the same operation to pin other apps to the taskbar.
3. Then you can use the Windows key along with the corresponding number key to open the programs on the taskbar with a keyboard shortcut. Based on the position of the pinned apps on the taskbar, they get a number from 1 to 9 from the left to the right. For instance, you can press Windows + 1 keyboard shortcut to open the first pinned app on the taskbar.

Source

Configuration

A configuration file is automatically generated when the program is ran for the first time. The location depends on the platform. On Linux: $HOME/.local/share/cappy/cappy.ini, on Windows: $HOME\AppData\Roaming\cappy\cappy.ini, and on Mac: $HOME/Library/Application Support/cappy/cappy.ini. All possible configuration is as follows:

Option	Description	Default
window_fullscreen	Sets the window to fullscreen, otherwise sets it as fullscreen borderless.	false
window_pre_crop	Pre-crop the image at initial startup. Requires 4 integers in the format: X Y WIDTH HEIGHT. If WIDTH is 0, then it is replaced with the capture width. If HEIGHT is 0, then it is replaced with the capture height.	0 0 0 0
flashlight_size	The initial flashlight radius in pixels.	150
flashlight_center_inner_color	The center color of the flashlight. Requires 4 integers between 0-255 in the format: REG GREEN BLUE ALPHA.	255 255 204 25
flashlight_center_outer_color	The center color of the flashlight. Requires 4 integers between 0-255 in the format: REG GREEN BLUE ALPHA.	255 255 204 25
flashlight_outer_color	The center color of the flashlight. Requires 4 integers between 0-255 in the format: REG GREEN BLUE ALPHA.	51 51 0 50
background_color	The center color of the flashlight. Requires 3 integers between 0-255 in the format: REG GREEN BLUE.	50 50 50
grid_size	The size of the grid in pixels.	100
grid_color	The color of the grid. Requires 3 integers between 0-255 in the format: REG GREEN BLUE.	200 200 200

Controls

Main

Key	Description
C	Enter/Exit color mode
F	Enter/Exit flashlight mode
R	Reset capture
G	Toggle grid
M	Minimize window
Right Click	Enter crop drawing mode
Left Drag	Pan
Scroll Wheel	Zoom
Ctrl+S	Save capture

Color Mode

You can hover your mouse over a pixel and a pop-up of the color information will appear near the mouse.

Key	Description
Ctrl+D	Copy color to clipboard as a decimal number
Ctrl+Shift+D	Copy color to clipboard as a decimal number, each channel separated by commas
Ctrl+H	Copy color to clipboard as a hexadecimal number
Ctrl+Shift+H	Copy color to clipboard as a hexadecimal number, each channel separated by commas
Ctrl+B	Copy color to clipboard as a binary number
Ctrl+Shift+B	Copy color to clipboard as a binary number, each channel separated by commas

Flashlight Mode

You can focus in on a specific point in flashlight mode.

Key	Description
LShift+Scroll Wheel	Increase/Decrease flashlight size

Crop Drawing Mode

Select a region of the capture.

Key	Description
Release Right Click	Finish drawing crop region
Drag	Continue drawing region
Shift+Drag	Continue drawing region as a square
Right Click (Outside cropped area)	Exit Crop Drawing Mode
X	Crop capture

TODO

• Flush all event that happen in between starting a save and ending a save.