1DTK_CREATE_COMPLEX_SHAPE(3) Draw Toolkit manual DTK_CREATE_COMPLEX_SHAPE(3)
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6 dtk_create_complex_shape - Creates or modify a shape to display custom
7 and evolving content
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10 #include <drawtk.h>
11 dtk_hshape dtk_create_complex_shape(dtk_hshape shp,
13 unsigned int nvert, const float *vertpos,
14 const float *vertcolor, const float *texcoords,
15 unsigned int nind, const unsigned int *ind,
16 unsigned int type, dtk_htex tex);
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19 dtk_create_complex_shape() creates a shape displaying a complex, custom
20 and possibly evolving content described by vertex attribute buffers
21 (vertpos, vertcolor and texcoords) and an array ind containing the
22 indices of vertices whose order describes how to connect the vertices
23 altogether in order to form primitives (controlled by type). tex can be
24 used to specify a texture to be mapped onto the shape.
25 vertpos should point to an array of nvert pairs of float values corre‐
27 sponding of the position (x,y) of each vertex. vertcolor should point
28 to an array of nvert quatuples of float values corresponding of the
29 color (R,G,B,A) of each vertex. texcoords can be either NULL or can
30 point to an array of nvert pairs of float values corresponding to the
31 texture coordinates (u,v) of the vertex. If texcoords is NULL, no tex‐
32 ture will be used even if tex is not null.
33 ind should point to an array of nind indices of the vertices in the
35 vertex attribute buffers. This list of indices determines how the ver‐
36 tices form the primitives and depends on type zhich can take one the
37 following value (See OpenGL manual to have detail):
38 DTK_TRIANGLE_STRIP
40 The first three vertices defines the first triangle (and their
41 order is significant). Each subsequent vertex defines a new tri‐
42 angle using that point along with two vertices from the previous
43 triangle.
44 DTK_TRIANGLE_FAN
46 A triangle fan is the same as a triangle strip with one excep‐
47 tion: the first vertex of the list is always the first vertex of
48 each triangle.
49 DTK_TRIANGLES
51 Separate triangles are specified. Every 3 indices defines in the
52 order a triangle. If nind is not a multiple of 3, the excedent 1
53 or 2 indices are ignored.
54 DTK_LINE_STRIP
56 A series of one or more connected line segments is specified by
57 enclosing a series of two or more endpoints. In this case, the
58 ith index specifies the end point of the i-1st segment and the
59 start point of the ith segment.
60 DTK_LINES
62 Individual line segments, each specified by a pair of vertices.
63 If nind is odd, then the last index is ignored.
64 shp can be used to modify a previously created shape. If it is non-
66 null, the handle will be used to modify the shape referenced by shp: no
67 new shape is created and the returned value is ensured to be shp in
68 case of success, NULL otherwise. If shp is NULL, the function will
69 attempt to create a new shape.
70 The arrays vertpos, vertcolor, texcoords and ind are not copied into
72 internal structures of the created shape. This allows one to dynami‐
73 cally change any aspect of the shape. However, in return it forces to
74 keep the buffers allocated during the whole life time of the shape.
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77 In case of success the function returns the handle to the newly created
78 or modified shape. If the shp argument is non-null, the handle returned
79 is the same value. In case of error, NULL is returned.
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82 The data contained into the buffers are accessed only during the cre‐
83 ation and the draw of the shape. So if the data is updated in a differ‐
84 ent thread than the one used for drawing, some locking is needed.
85
87 dtk_create_shape(3)
88EPFL 2010 DTK_CREATE_COMPLEX_SHAPE(3)