vk-gears

Runs on:

QNX OS

Vulkan options:

-composite=composite_value

Use alpha compositing through Vulkan WSI. Alpha compositing combines the image with it's background to create the appearance of partial or full transparency. You can choose from the following options:

• 0 - VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR: If the alpha component is present, it is ignored and is treated as a constant value of 1.0 (opaque). This is the default.
• 1 - VK_COMPOSITE_ALPHA_INHERIT_BIT_KHR: Vulkan APIs are unaware of how the presentation engine treats the alpha component in the images. In this setting, the application is responsible for setting the composite alpha blending mode, by using native window system commands. If the application does not set the blending mode, a platform specific default is used. You can combine this option with the -transparency option.
• 2 - VK_COMPOSITE_ALPHA_POST_MULTIPLIED_BIT_KHR: If the alpha component is present, it is used in the compositing process. The compositor multiplies the non-alpha component of the image with the alpha component during composition.
• 3 - VK_COMPOSITE_ALPHA_PRE_MULTIPLIED_BIT_KHR: If the alpha component is present, it is used in the compositing process. Your application needs to multiply the non-alpha component with the alpha component.

-gpu=gpu_index

Use gpu_index to specify the GPU to use. If this option is not set, the default is -1. auto-detect the fasted GPU (index is -1).

-nbuffers=count

Set the number of window buffers to be created for rendering. Use an integer from 2 to the maximum buffer limit of your driver. The default is 3.

-present= mode

Set the presentation mode. Chose from the following:

• 0 - VK_PRESENT_MODE_IMMEDIATE_KHR
• 1 - VK_PRESENT_MODE_MAILBOX_KHR
• 2 - VK_PRESENT_MODE_FIFO_KHR (default)
• 3 - VK_PRESENT_MODE_FIFO_RELAXED_KHR

If you set both this option and -interval, the last specified option is used.

-tex= texture

This option enables textured gears using compression. Choose from the following compression methods:

• None - Do not apply texture (default).
• etc2 - Use ETC2 compression.
• astc - ASTC compression.
• pvrt - PVRTC1 compression. The VK_IMG_format_pvrtc is required.

-validate

Enable any installed validation layers.

-verbose

Print information to display.

Screen options:

-bg-alpha=background_alpha_value

Set the background to the specified alpha value as a float in the range [0.0f..1.0f]. The default is 0.0f.

-display=display_id

Specify which display the window will appear on by using display_id. Where display_id is an integer that identifies one of the displays that you've configured in the display subsections of the winmgr section in your configuration file (e.g., graphics.conf).

If you don't have any display subsections configured, or if you don't specify the display option, then vk-gears uses the default display.

-fg-alpha=foreground_alpha_value

Set the foreground to the specified alpha value as a float in the range [0.0f..1.0f]. The default is 1.0f.

-format=pixel_format

Set the window pixel format. Supported formats are:

• rgb565 - SCREEN_FORMAT_RGB565
• rgba5551 - SCREEN_FORMAT_RGBA5551
• rgbx5551 - SCREEN_FORMAT_RGBX5551
• rgba8888 - SCREEN_FORMAT_RGBA8888
• rgbx8888 - SCREEN_FORMAT_RGBX8888
• bgra8888 - SCREEN_FORMAT_BGRA8888
• bgrx8888 - SCREEN_FORMAT_BGRX8888
• rgba1010102 - SCREEN_FORMAT_RGBA1010102
• rgbx1010102 - SCREEN_FORMAT_RGBX1010102
• bgra1010102 - SCREEN_FORMAT_BGRA1010102
• bgrx1010102 - SCREEN_FORMAT_BGRX1010102

If you do not set this option, Screen uses the format of the window's framebuffer. If the framebuffer's format is not supported by Vulkan, vk-gears will abort.

-frame-limit=frame_limit

Limit the number of frames rendered to the value specified by frame_limit (integer); after the frame limit is reached, vk-gears exits. The default is an unlimited number of frames (-1).

-interval=mode

Set the presentation mode. Chose from the following:

• 0 for VK_PRESENT_MODE_IMMEDIATE_KHR
• 1 for VK_PRESENT_MODE_FIFO_KHR

If you do not set this option, Screen uses the value or default of -present_mode.

If you set this option and -present, the last specified option is used.

-pipeline=pipeline_id

Set the pipeline as specified by pipeline_id (integer). If you don't specify this option, vk-gears uses the pipeline of the framebuffer.

If you use this option, Screen applies the SCREEN_USAGE_OVERLAY usage flag and uses the pipeline specified by pipeline_id.

-pos=x,y

Sets the x,y coordinates of the viewport. The default coordinate of 0,0 is used if this option isn't specified.

-size=widthxheight

Set the size as specified, using integer values for width and height in pixels, of the viewport. The default size is fullscreen.

-transparency=transparency_mode

Set the transparency mode of the window. Valid transparency modes are:

Transparency mode	Description
none	Default mode; result is an opaque window
test	Destination pixels are replaced by source pixels; pixels may be opaque or fully transparent
src	Destination pixels are replaced by source pixels, including the alpha channel; window will be blended with contents underneath it

-zorder=zorder

Set the z-order specified by zorder, as an integer, of the window. A z-order of 0 is used if this option isn't specified.

Description:

The vk-gears binary is a command-line tool that can be used to confirm that screen is running, and that all necessary drivers for Vulkan are in place, and can start successfully.

To control vk-gears, use the following keys:

• ESC - Quit the demo
• F - Pause/resume the demo

Examples:

# vk-gears