3 * Mesa 3-D graphics library
6 * Copyright (C) 1999-2003 Brian Paul All Rights Reserved.
8 * Permission is hereby granted, free of charge, to any person obtaining a
9 * copy of this software and associated documentation files (the "Software"),
10 * to deal in the Software without restriction, including without limitation
11 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
12 * and/or sell copies of the Software, and to permit persons to whom the
13 * Software is furnished to do so, subject to the following conditions:
15 * The above copyright notice and this permission notice shall be included
16 * in all copies or substantial portions of the Software.
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
22 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
23 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
31 #include "t_context.h"
32 #include "t_pipeline.h"
35 struct point_stage_data
{
39 #define POINT_STAGE_DATA(stage) ((struct point_stage_data *)stage->privatePtr)
43 * Compute attenuated point sizes
45 static GLboolean
run_point_stage( GLcontext
*ctx
,
46 struct tnl_pipeline_stage
*stage
)
48 struct point_stage_data
*store
= POINT_STAGE_DATA(stage
);
49 struct vertex_buffer
*VB
= &TNL_CONTEXT(ctx
)->vb
;
50 const GLfloat (*eye
)[4] = (const GLfloat (*)[4]) VB
->EyePtr
->data
;
51 const GLfloat p0
= ctx
->Point
.Params
[0];
52 const GLfloat p1
= ctx
->Point
.Params
[1];
53 const GLfloat p2
= ctx
->Point
.Params
[2];
54 const GLfloat pointSize
= ctx
->Point
._Size
;
55 GLfloat (*size
)[4] = store
->PointSize
.data
;
58 if (stage
->changed_inputs
) {
59 /* XXX do threshold and min/max clamping here? */
60 for (i
= 0; i
< VB
->Count
; i
++) {
61 const GLfloat dist
= -eye
[i
][2];
62 /* GLfloat dist = SQRTF(pos[0]*pos[0]+pos[1]*pos[1]+pos[2]*pos[2]);*/
63 size
[i
][0] = pointSize
/ (p0
+ dist
* (p1
+ dist
* p2
));
67 VB
->PointSizePtr
= &store
->PointSize
;
68 VB
->AttribPtr
[_TNL_ATTRIB_POINTSIZE
] = &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 tnl_pipeline_stage
*d
)
79 d
->active
= ctx
->Point
._Attenuated
&& !ctx
->VertexProgram
.Enabled
;
82 static GLboolean
alloc_point_data( GLcontext
*ctx
,
83 struct tnl_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 tnl_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 tnl_pipeline_stage _tnl_point_attenuation_stage
=
113 "point size attenuation", /* name */
114 _NEW_POINT
|_NEW_PROGRAM
, /* check_state */
115 _NEW_POINT
, /* run_state */
116 GL_FALSE
, /* active */
117 _TNL_BIT_POS
, /* inputs */
118 _TNL_BIT_POS
, /* 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 */