Changes in HelpTerrains

Revision Differences of Revision 3

Terrains are some of the base graphics in widelands. THis page describes how they are implemented. ¶
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# The terrain patterns ¶
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The patterns for terrains have some restrictions: ¶
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1. Width/height: 64 pixel ¶
2. They must be color indexed ¶
3. They couldn't get transparent areas ¶
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# Implemeting ¶
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The surface of the widelands terrain consists of a lot of triangles. See [geometry](https://wl.widelands.org/docs/wl/geometry/) on more about this issue. The squared terrain patterns are therefore splitted into trinagles too. Look at this terrain pattern. It shows how the splitting is made: ¶
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![test.png](/wlmedia//wlimages/test.png) ¶
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The pattern is splitted into 4 trinangles, which are represented with the different colors. While rendering only one of those triangles are displayed for each field: ¶
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![terrain_split_2.jpg](/wlmedia//wlimages/terrain_split_2.jpg) ¶
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Note that the red and white triangles of the original pattern are sampled to one big red and one big white triangle. ¶
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![terrain_split_1.jpg](/wlmedia//wlimages/terrain_split_3.jpg) ¶