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hud_coordinate_system [2017/04/18 16:31] – korshun | hud_coordinate_system [2017/04/18 16:39] (current) – korshun |
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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. | 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. |
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| The HUD coordinate system's rectangle width and height are specified in [[zdoom>SetHudSize]]. |
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ACSUtils provides functions to correctly work with the HUD coordinate system. | ACSUtils provides functions to correctly work with the HUD coordinate system. |
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| <note important>All functions here work with fixed-point numbers. The restriction on integers in ZDoom is completely arbitrary.</note> |
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===== Retrieve aspect ratio ===== | ===== Retrieve aspect ratio ===== |
[[functions:GetAspectRatio]] returns the aspect ratio that ZDoom assumes the screen is. ZDoom uses tricky code for that. | [[functions:GetAspectRatio]] returns the aspect ratio that ZDoom assumes the screen is. ZDoom uses tricky code for that. |
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| ===== 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. |
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| 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]]. |
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| ===== 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]]. |
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| 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. |
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| ===== Examples ===== |
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| Put a message in the top left corner of the screen: |
| <code> |
| HudSetVirtualSize(640.0, 480.0); |
| x = HudLeft(); // This will be negative in widescreen. |
| y = 0.0; |
| </code> |
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