oglsnoop(1G)
oglsnoop - magnify and report on the screen under the mouse pointer
As shipped in IRIX 6.5.30. Unchanged since IRIX 6.5.
NAME oglsnoop - magnify and report on the screen under the mouse pointer SYNOPSIS oglsnoop DESCRIPTION oglsnoop is a program for viewing the color, depth and stencil values of windows on the desktop. It displays these values graphically as well as numerically in its window. oglsnoop can be used to determine the Visual and Colormap that a given window is using. It can view both the Front and Back buffers of Double Buffered windows and allows you to visualize the Depth and Stencil Buffers using a grey scale display. oglsnoop has an Information dialog to view information about the window currently being watched and an Advanced dialog for controlling the visual mapping of depth values to grey scale color ranges. Most key information is displayed in the oglsnoop title bar for quick reference. The oglsnoop title bar displays the following information.... Zoom Factor A number defining the magnification factor of the image. Buffer Type Color Index shows CI and True Color shows RGBA. Single/Double SINGLE for single buffered visuals and DOUBLE for double buffered ones. Visual ID Visual Id as a hexadecimal number. These equate to the numbers in glxinfo's output. Current Buffer Blank indicates the Color buffer, D for Depth and S for Stencil. Front/Back F for the front buffer and B for back. If the current window isn't double buffered then nothing will be displayed here. In the bottom of the oglsnoop window is a bar that displays the values for the current pixel. When oglsnoop is following the mouse then these values represent the pixel at the current pointer position. When you have grabbed a window then these values represent the pixel at the currently grabbed window position. The represented values are X and Y coordinates, Red Green Blue and Alpha color values in hex, Depth value in the range 0.0 -> 1.0, Stencil value in the range 0 -> maximum stencil value, and the Color Index value. All values shown are for the current pixel. The X and Y coordinates are relative to the Upper Left Corner of the display when in Normal Mode and the Lower Left Corner of the grabbed window when in Grab Mode. The Mode menu contains a radio box for selecting the current buffer to display. Available choices are Color, Depth and Stencil. Although values are read from all buffers at the current pixel position only one of the buffers can be displayed visually at a time. The Option menu contains controls that affect what is currently displayed. The Snoop toggle turns on/off the display of the current pixel values. The ABGR toggle reverses the display of color values from RGBA to ABGR. The Grid toggle brings up a grid that is overlaid on the oglsnoop window. This can be useful for counting pixels. The Information... button brings up an Information dialog that displays more information about the current window. The Advanced... button brings up an Advanced dialog that allows you to modify the Depth and Stencil ranges being displayed. The Advanced dialog is only useful when viewing the Depth or Stencil buffers. When you are viewing a Depth or Stencil buffer the range of values is mapped to the color range to display grey scale equivalents of the values. When the automatic toggles are set the ranges are calculated on the fly. If the automatic toggle is not set then you can change the way that depth or stencil values are mapped to color values. The Minimum sliders control the percent of the available ranges that map to white (ie. since Depth always ranges for 0.1 to 1.0 a Minimum Depth Setting of 90 would mean that depth values of 0.9 map to white ). The Maximum sliders control the percent of the available ranges that map to black (ie. a Maximum Depth setting of 100 would mean that depth values of 1.0 would map to black ). The scale is then linearly mapped from the Minimum to the Maximum along the given color resolution. If the Minimum and Maximum sliders are reversed (.ie Minimum is set to 100 and Maximum is set to 90 ), then the grey scale values are reversed (ie. a Depth value of 1.0 now maps to White and a Depth value of 0.9 maps to Black ) or Near things are dark and far things are light. The View menu contains controls that affect how information is read. The Zoom++ and Zoom-- buttons increase and decrease the zoom factor by one each time. The current zoom factor is displayed in the title bar. The Grab Window button activates the grab mechanism which allows you to select a window to watch regardless of where the mouse pointer is. When in Grab Mode if the mouse is placed over the oglsnoop window then you can use the arrow keys to navigate around the currently grabbed window. The X and Y coordinates displayed will be relative to the Lower Left Corner of the grabbed window. To leave Grab Mode and go back to Normal Mode just click on the Grab Window Button again ( it we be labeled as Ungrab Window if you are in Grab Mode ). If oglsnoop is unable to grab a window successfully it will remain in Normal Mode. The last button on the View menu is the Read Back Buffer button. When this toggle is set then the back buffer is read instead of the front on double buffered windows. Along with the menus most functions can be accessed with the keyboard. The following is the list of keymappings... esc quit 1-9 set zoom factor 0 set zoom factor to 10 d set zoom factor to 30 m go to next display mode (ie. Color -> Depth -> Stencil ) b toggle back buffer reading on/off g grab/ungrab window s toggle snoop mode r reverse color display ABGR -> RGBA + increase zoom factor by 1 - decrease zoom factor by 1 The oglsnoop window can be resized to display a larger or smaller area. When the oglsnoop window is not iconified it can use up to 30% of the available cpu, so it might be wise to iconify it when you aren't using it. NOTES oglsnoop only views the top most window under the current mouse position. Often this window is an overlay which is above the main graphics window. If a window is using a Visual which isn't OpenGL compatible then oglsnoop will not be able to grab this window and likewise won't be able to read depth, stencil or Color Index values from it. If a window is using a Visual that has Depth and Stencil buffers associated with it then oglsnoop will display depth and stencil values even though these values may be garbage. When first entering a window or after moving a grabbed window you may need to cause the window to be redrawn for the proper values to be read from the window. SEE ALSO glxinfo(1g)