1 /* $Id: t_vb_points.c,v 1.11 2003/03/01 01:50:27 brianp Exp $ */
4 * Mesa 3-D graphics library
7 * Copyright (C) 1999-2003 Brian Paul All Rights Reserved.
9 * Permission is hereby granted, free of charge, to any person obtaining a
10 * copy of this software and associated documentation files (the "Software"),
11 * to deal in the Software without restriction, including without limitation
12 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
13 * and/or sell copies of the Software, and to permit persons to whom the
14 * Software is furnished to do so, subject to the following conditions:
16 * The above copyright notice and this permission notice shall be included
17 * in all copies or substantial portions of the Software.
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
20 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
23 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
24 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
32 #include "t_context.h"
33 #include "t_pipeline.h"
36 struct point_stage_data
{
40 #define POINT_STAGE_DATA(stage) ((struct point_stage_data *)stage->privatePtr)
44 * Compute attenuated point sizes
46 static GLboolean
run_point_stage( GLcontext
*ctx
,
47 struct gl_pipeline_stage
*stage
)
49 struct point_stage_data
*store
= POINT_STAGE_DATA(stage
);
50 struct vertex_buffer
*VB
= &TNL_CONTEXT(ctx
)->vb
;
51 const GLfloat (*eye
)[4] = (const GLfloat (*)[4]) VB
->EyePtr
->data
;
52 const GLfloat p0
= ctx
->Point
.Params
[0];
53 const GLfloat p1
= ctx
->Point
.Params
[1];
54 const GLfloat p2
= ctx
->Point
.Params
[2];
55 const GLfloat pointSize
= ctx
->Point
._Size
;
56 GLfloat (*size
)[4] = store
->PointSize
.data
;
59 if (stage
->changed_inputs
) {
60 /* XXX do threshold and min/max clamping here? */
61 for (i
= 0; i
< VB
->Count
; i
++) {
62 const GLfloat dist
= -eye
[i
][2];
63 /* GLfloat dist = SQRTF(pos[0]*pos[0]+pos[1]*pos[1]+pos[2]*pos[2]);*/
64 size
[i
][0] = pointSize
/ (p0
+ dist
* (p1
+ dist
* p2
));
68 VB
->PointSizePtr
= &store
->PointSize
;
74 /* If point size attenuation is on we'll compute the point size for
75 * each vertex in a special pipeline stage.
77 static void check_point_size( GLcontext
*ctx
, struct gl_pipeline_stage
*d
)
79 d
->active
= ctx
->Point
._Attenuated
&& !ctx
->VertexProgram
.Enabled
;
82 static GLboolean
alloc_point_data( GLcontext
*ctx
,
83 struct gl_pipeline_stage
*stage
)
85 struct vertex_buffer
*VB
= &TNL_CONTEXT(ctx
)->vb
;
86 struct point_stage_data
*store
;
87 stage
->privatePtr
= MALLOC(sizeof(*store
));
88 store
= POINT_STAGE_DATA(stage
);
92 _mesa_vector4f_alloc( &store
->PointSize
, 0, VB
->Size
, 32 );
96 stage
->run
= run_point_stage
;
97 return stage
->run( ctx
, stage
);
101 static void free_point_data( struct gl_pipeline_stage
*stage
)
103 struct point_stage_data
*store
= POINT_STAGE_DATA(stage
);
105 _mesa_vector4f_free( &store
->PointSize
);
107 stage
->privatePtr
= 0;
111 const struct gl_pipeline_stage _tnl_point_attenuation_stage
=
113 "point size attenuation", /* name */
114 _NEW_POINT
, /* build_state_change */
115 _NEW_POINT
, /* run_state_change */
116 GL_FALSE
, /* active */
117 VERT_BIT_EYE
, /* inputs */
118 VERT_BIT_POINT_SIZE
, /* outputs */
119 0, /* changed_inputs (temporary value) */
120 NULL
, /* stage private data */
121 free_point_data
, /* destructor */
122 check_point_size
, /* check */
123 alloc_point_data
/* run -- initially set to alloc data */