1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
/**************************************************************************
*
* Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sub license, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
* IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
**************************************************************************/
/* Authors: Keith Whitwell <keith@tungstengraphics.com>
*/
/* Implement line stipple by cutting lines up into smaller lines.
* There are hundreds of ways to implement line stipple, this is one
* choice that should work in all situations, requires no state
* manipulations, but with a penalty in terms of large amounts of
* generated geometry.
*/
#include "pipe/p_util.h"
#include "pipe/p_defines.h"
#include "pipe/p_shader_tokens.h"
#include "draw_private.h"
/** Subclass of draw_stage */
struct stipple_stage {
struct draw_stage stage;
float counter;
uint pattern;
uint factor;
};
static INLINE struct stipple_stage *
stipple_stage(struct draw_stage *stage)
{
return (struct stipple_stage *) stage;
}
/**
* Compute interpolated vertex attributes for 'dst' at position 't'
* between 'v0' and 'v1'.
* XXX using linear interpolation for all attribs at this time.
*/
static void
screen_interp( struct draw_context *draw,
struct vertex_header *dst,
float t,
const struct vertex_header *v0,
const struct vertex_header *v1 )
{
uint attr;
for (attr = 0; attr < draw->num_vs_outputs; attr++) {
const float *val0 = v0->data[attr];
const float *val1 = v1->data[attr];
float *newv = dst->data[attr];
uint i;
for (i = 0; i < 4; i++) {
newv[i] = val0[i] + t * (val1[i] - val0[i]);
}
}
}
static void
emit_segment(struct draw_stage *stage, struct prim_header *header,
float t0, float t1)
{
struct vertex_header *v0new = dup_vert(stage, header->v[0], 0);
struct vertex_header *v1new = dup_vert(stage, header->v[1], 1);
struct prim_header newprim = *header;
if (t0 > 0.0) {
screen_interp( stage->draw, v0new, t0, header->v[0], header->v[1] );
newprim.v[0] = v0new;
}
if (t1 < 1.0) {
screen_interp( stage->draw, v1new, t1, header->v[0], header->v[1] );
newprim.v[1] = v1new;
}
stage->next->line( stage->next, &newprim );
}
static INLINE unsigned
stipple_test(int counter, ushort pattern, int factor)
{
int b = (counter / factor) & 0xf;
return (1 << b) & pattern;
}
static void
stipple_line(struct draw_stage *stage, struct prim_header *header)
{
struct stipple_stage *stipple = stipple_stage(stage);
struct vertex_header *v0 = header->v[0];
struct vertex_header *v1 = header->v[1];
const float *pos0 = v0->data[0];
const float *pos1 = v1->data[0];
float start = 0;
int state = 0;
float x0 = pos0[0];
float x1 = pos1[0];
float y0 = pos0[1];
float y1 = pos1[1];
float dx = x0 > x1 ? x0 - x1 : x1 - x0;
float dy = y0 > y1 ? y0 - y1 : y1 - y0;
float length = MAX2(dx, dy);
int i;
/* XXX ToDo: intead of iterating pixel-by-pixel, use a look-up table.
*/
for (i = 0; i < length; i++) {
int result = stipple_test( (int) stipple->counter+i,
(ushort) stipple->pattern, stipple->factor );
if (result != state) {
/* changing from "off" to "on" or vice versa */
if (state) {
if (start != i) {
/* finishing an "on" segment */
emit_segment( stage, header, start / length, i / length );
}
}
else {
/* starting an "on" segment */
start = (float) i;
}
state = result;
}
}
if (state && start < length)
emit_segment( stage, header, start / length, 1.0 );
stipple->counter += length;
}
static void
reset_stipple_counter(struct draw_stage *stage)
{
struct stipple_stage *stipple = stipple_stage(stage);
stipple->counter = 0;
stage->next->reset_stipple_counter( stage->next );
}
static void
stipple_first_line(struct draw_stage *stage,
struct prim_header *header)
{
struct stipple_stage *stipple = stipple_stage(stage);
struct draw_context *draw = stage->draw;
stipple->pattern = draw->rasterizer->line_stipple_pattern;
stipple->factor = draw->rasterizer->line_stipple_factor + 1;
stage->line = stipple_line;
stage->line( stage, header );
}
static void
stipple_flush(struct draw_stage *stage, unsigned flags)
{
stage->line = stipple_first_line;
stage->next->flush( stage->next, flags );
}
static void
passthrough_point(struct draw_stage *stage, struct prim_header *header)
{
stage->next->point( stage->next, header );
}
static void
passthrough_tri(struct draw_stage *stage, struct prim_header *header)
{
stage->next->tri(stage->next, header);
}
static void
stipple_destroy( struct draw_stage *stage )
{
draw_free_temp_verts( stage );
FREE( stage );
}
/**
* Create line stippler stage
*/
struct draw_stage *draw_stipple_stage( struct draw_context *draw )
{
struct stipple_stage *stipple = CALLOC_STRUCT(stipple_stage);
draw_alloc_temp_verts( &stipple->stage, 2 );
stipple->stage.draw = draw;
stipple->stage.next = NULL;
stipple->stage.point = passthrough_point;
stipple->stage.line = stipple_first_line;
stipple->stage.tri = passthrough_tri;
stipple->stage.reset_stipple_counter = reset_stipple_counter;
stipple->stage.flush = stipple_flush;
stipple->stage.destroy = stipple_destroy;
return &stipple->stage;
}
|
