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hud_coordinate_system [2017/04/17 14:56]
korshun created
hud_coordinate_system [2017/04/18 16:39]
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 ====== HUD coordinate system ====== ====== HUD coordinate system ======
 +ZDoom uses a special coordinate system for [[zdoom>HudMessage]]s. In 4:3 resolutions, the coordinate system's rectangle matches that of the screen. In aspect ratios other than that, a 4:3 rectangle is put at the center of the screen and the remaining screen space is out of its boundaries.
 +The HUD coordinate system's rectangle width and height are specified in [[zdoom>SetHudSize]].
 +ACSUtils provides functions to correctly work with the HUD coordinate system.
 +<note important>All functions here work with fixed-point numbers. The restriction on integers in ZDoom is completely arbitrary.</note>
 +===== Retrieve aspect ratio =====
 +[[functions:GetAspectRatio]] returns the aspect ratio that ZDoom assumes the screen is. ZDoom uses tricky code for that.
 +===== Actual screen boundaries =====
 +[[functions:HudLeftFor]], [[functions:HudRightFor]], [[functions:HudTopFor]] and [[functions:HudBottomFor]] return actual screen boundaries in the HUD coordinate system for the specified width and height of the HUD coordinate system, taking the current aspect ratio into account.
 +To avoid specifying a width or height every time, you can call [[functions:HudSetVirtualSize]] once and then call [[functions:HudLeft]], [[functions:HudRight]], [[functions:HudTop]] and [[functions:HudBottom]].
 +===== HUD borders =====
 +Borders are the areas of the screen that are not covered by the aforementioned rectangle. Horizontal and vertical border width can be retrieved using [[functions:HudBorderXFor]] and [[functions:HudBorderYFor]].
 +As with screen boundaries, you can just call [[functions:HudSetVirtualSize]] once and then use [[functions:HudBorderX]] and [[functions:HudBorderY]] without specifying the size of the HUD coordinate system every time.
 +===== Examples =====
 +Put a message in the top left corner of the screen:
 +HudSetVirtualSize(640.0, 480.0);
 +x = HudLeft(); // This will be negative in widescreen.
 +y = 0.0;
hud_coordinate_system.txt ยท Last modified: 2017/04/18 16:39 by korshun