From: <el...@us...> - 2010-09-12 15:25:02
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Revision: 13723 http://alleg.svn.sourceforge.net/alleg/?rev=13723&view=rev Author: elias Date: 2010-09-12 15:24:55 +0000 (Sun, 12 Sep 2010) Log Message: ----------- small documentation clarification about al_draw_prim's vertex declaration Modified Paths: -------------- allegro/branches/4.9/docs/src/refman/primitives.txt Modified: allegro/branches/4.9/docs/src/refman/primitives.txt =================================================================== --- allegro/branches/4.9/docs/src/refman/primitives.txt 2010-09-12 13:50:30 UTC (rev 13722) +++ allegro/branches/4.9/docs/src/refman/primitives.txt 2010-09-12 15:24:55 UTC (rev 13723) @@ -345,8 +345,8 @@ * texture - Texture to use, pass 0 to use only color shaded primitves * vtxs - Pointer to an array of vertices -* decl - Pointer to a vertex declaration. If set to 0, the vtxs are assumed - to be of the ALLEGRO_VERTEX type +* decl - Pointer to a vertex declaration. If set to NULL, the vertices + are assumed to be of the ALLEGRO_VERTEX type * start, end - Start and end of the subset of the vertex buffer to draw * type - Primitive type to draw @@ -496,8 +496,12 @@ generally occur in an array. The last element of such an array should have the attribute field equal to 0, to signify that it is the end of the array. Here is an example code that would create a declaration describing the -ALLEGRO_VERTEX structure: +ALLEGRO_VERTEX structure (passing this as vertex declaration to +al_draw_prim would be identical to passing NULL): + /* On compilers without the offsetof keyword you need to obtain the + * offset with sizeof and make sure to account for packing. + */ ALLEGRO_VERTEX_ELEMENT elems[] = { {ALLEGRO_PRIM_POSITION, ALLEGRO_PRIM_FLOAT_3, offsetof(ALLEGRO_VERTEX, x)}, {ALLEGRO_PRIM_TEX_COORD_PIXEL, ALLEGRO_PRIM_FLOAT_2, offsetof(ALLEGRO_VERTEX, u)}, This was sent by the SourceForge.net collaborative development platform, the world's largest Open Source development site. |