2 * Mesa 3-D graphics library
5 * Copyright (C) 1999-2004 Brian Paul All Rights Reserved.
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
21 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
26 * Regarding GL_NV_point_sprite:
28 * Portions of this software may use or implement intellectual
29 * property owned and licensed by NVIDIA Corporation. NVIDIA disclaims
30 * any and all warranties with respect to such intellectual property,
31 * including any use thereof or modifications thereto.
36 * Point rendering template code.
38 * Set FLAGS = bitwise-OR of the following tokens:
40 * RGBA = do rgba instead of color index
41 * SMOOTH = do antialiasing
42 * TEXTURE = do texture coords
43 * SPECULAR = do separate specular color
44 * LARGE = do points with diameter > 1 pixel
45 * ATTENUATE = compute point size attenuation
46 * SPRITE = GL_ARB_point_sprite / GL_NV_point_sprite
48 * Notes: LARGE and ATTENUATE are exclusive of each other.
49 * TEXTURE requires RGBA
54 * NOTES on antialiased point rasterization:
56 * Let d = distance of fragment center from vertex.
58 * fragment has 100% coverage
59 * else if d > rmax2 then
60 * fragment has 0% coverage
62 * fragment has % coverage = (d - rmin2) / (rmax2 - rmin2)
68 NAME ( GLcontext
*ctx
, const SWvertex
*vert
)
70 #if FLAGS & (ATTENUATE | LARGE | SMOOTH | SPRITE)
74 #if (FLAGS & ATTENUATE) && (FLAGS & SMOOTH)
77 const GLchan red
= vert
->color
[0];
78 const GLchan green
= vert
->color
[1];
79 const GLchan blue
= vert
->color
[2];
80 const GLchan alpha
= vert
->color
[3];
83 const GLchan specRed
= vert
->specular
[0];
84 const GLchan specGreen
= vert
->specular
[1];
85 const GLchan specBlue
= vert
->specular
[2];
88 const GLuint colorIndex
= (GLuint
) vert
->index
; /* XXX round? */
91 GLfloat texcoord
[MAX_TEXTURE_COORD_UNITS
][4];
94 SWcontext
*swrast
= SWRAST_CONTEXT(ctx
);
95 struct sw_span
*span
= &(swrast
->PointSpan
);
97 /* Cull primitives with malformed coordinates.
100 float tmp
= vert
->win
[0] + vert
->win
[1];
101 if (IS_INF_OR_NAN(tmp
))
108 span
->interpMask
= SPAN_FOG
;
109 span
->arrayMask
= SPAN_XY
| SPAN_Z
;
110 span
->fog
= vert
->fog
;
113 span
->arrayMask
|= SPAN_RGBA
;
116 span
->arrayMask
|= SPAN_SPEC
;
119 span
->arrayMask
|= SPAN_INDEX
;
122 span
->arrayMask
|= SPAN_TEXTURE
;
123 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
124 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
125 const GLfloat q
= vert
->texcoord
[u
][3];
126 const GLfloat invQ
= (q
== 0.0F
|| q
== 1.0F
) ? 1.0F
: (1.0F
/ q
);
127 texcoord
[u
][0] = vert
->texcoord
[u
][0] * invQ
;
128 texcoord
[u
][1] = vert
->texcoord
[u
][1] * invQ
;
129 texcoord
[u
][2] = vert
->texcoord
[u
][2] * invQ
;
135 span
->arrayMask
|= SPAN_COVERAGE
;
138 span
->arrayMask
|= SPAN_TEXTURE
;
141 #if FLAGS & ATTENUATE
142 if (vert
->pointSize
>= ctx
->Point
.Threshold
) {
143 size
= MIN2(vert
->pointSize
, ctx
->Point
.MaxSize
);
144 #if (FLAGS & RGBA) && (FLAGS & SMOOTH)
149 #if (FLAGS & RGBA) && (FLAGS & SMOOTH)
150 GLfloat dsize
= vert
->pointSize
/ ctx
->Point
.Threshold
;
151 alphaAtten
= dsize
* dsize
;
153 size
= MAX2(ctx
->Point
.Threshold
, ctx
->Point
.MinSize
);
155 #elif FLAGS & (LARGE | SMOOTH | SPRITE)
156 size
= ctx
->Point
._Size
;
159 #if FLAGS & (ATTENUATE | LARGE | SMOOTH | SPRITE)
165 const GLfloat radius
= 0.5F
* size
;
166 const GLint z
= (GLint
) (vert
->win
[2] + 0.5F
);
169 const GLfloat rmin
= radius
- 0.7071F
; /* 0.7071 = sqrt(2)/2 */
170 const GLfloat rmax
= radius
+ 0.7071F
;
171 const GLfloat rmin2
= MAX2(0.0F
, rmin
* rmin
);
172 const GLfloat rmax2
= rmax
* rmax
;
173 const GLfloat cscale
= 1.0F
/ (rmax2
- rmin2
);
174 const GLint xmin
= (GLint
) (vert
->win
[0] - radius
);
175 const GLint xmax
= (GLint
) (vert
->win
[0] + radius
);
176 const GLint ymin
= (GLint
) (vert
->win
[1] - radius
);
177 const GLint ymax
= (GLint
) (vert
->win
[1] + radius
);
180 GLint xmin
, xmax
, ymin
, ymax
;
181 GLint iSize
= (GLint
) (size
+ 0.5F
);
183 iSize
= MAX2(1, iSize
);
187 xmin
= (GLint
) (vert
->win
[0] - iRadius
);
188 xmax
= (GLint
) (vert
->win
[0] + iRadius
);
189 ymin
= (GLint
) (vert
->win
[1] - iRadius
);
190 ymax
= (GLint
) (vert
->win
[1] + iRadius
);
194 xmin
= (GLint
) vert
->win
[0] - iRadius
+ 1;
195 xmax
= xmin
+ iSize
- 1;
196 ymin
= (GLint
) vert
->win
[1] - iRadius
+ 1;
197 ymax
= ymin
+ iSize
- 1;
201 /* check if we need to flush */
202 if (span
->end
+ (xmax
-xmin
+1) * (ymax
-ymin
+1) >= MAX_WIDTH
||
203 (swrast
->_RasterMask
& (BLEND_BIT
| LOGIC_OP_BIT
| MASKING_BIT
))) {
204 #if FLAGS & (TEXTURE | SPRITE)
205 if (ctx
->Texture
._EnabledUnits
)
206 _swrast_write_texture_span(ctx
, span
);
208 _swrast_write_rgba_span(ctx
, span
);
210 _swrast_write_rgba_span(ctx
, span
);
212 _swrast_write_index_span(ctx
, span
);
218 * OK, generate fragments
222 for (y
= ymin
; y
<= ymax
; y
++) {
223 for (x
= xmin
; x
<= xmax
; x
++) {
224 #if FLAGS & (SPRITE | TEXTURE)
229 span
->array
->rgba
[count
][RCOMP
] = red
;
230 span
->array
->rgba
[count
][GCOMP
] = green
;
231 span
->array
->rgba
[count
][BCOMP
] = blue
;
232 span
->array
->rgba
[count
][ACOMP
] = alpha
;
235 span
->array
->spec
[count
][RCOMP
] = specRed
;
236 span
->array
->spec
[count
][GCOMP
] = specGreen
;
237 span
->array
->spec
[count
][BCOMP
] = specBlue
;
240 span
->array
->index
[count
] = colorIndex
;
243 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
244 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
245 COPY_4V(span
->array
->texcoords
[u
][count
], texcoord
[u
]);
251 /* compute coverage */
253 const GLfloat dx
= x
- vert
->win
[0] + 0.5F
;
254 const GLfloat dy
= y
- vert
->win
[1] + 0.5F
;
255 const GLfloat dist2
= dx
* dx
+ dy
* dy
;
257 if (dist2
>= rmin2
) {
258 /* compute partial coverage */
259 span
->array
->coverage
[count
] = 1.0F
- (dist2
- rmin2
) * cscale
;
261 /* coverage in [0,15] */
262 span
->array
->coverage
[count
] *= 15.0;
267 span
->array
->coverage
[count
] = 1.0F
;
270 span
->array
->x
[count
] = x
;
271 span
->array
->y
[count
] = y
;
272 span
->array
->z
[count
] = z
;
274 #if (FLAGS & ATTENUATE) && (FLAGS & RGBA)
275 span
->array
->rgba
[count
][ACOMP
] = (GLchan
) (alpha
* alphaAtten
);
277 span
->array
->rgba
[count
][ACOMP
] = alpha
;
285 /* not smooth (square points) */
286 span
->array
->x
[count
] = x
;
287 span
->array
->y
[count
] = y
;
288 span
->array
->z
[count
] = z
;
291 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
292 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
293 if (ctx
->Point
.CoordReplace
[u
]) {
294 GLfloat s
= 0.5F
+ (x
+ 0.5F
- vert
->win
[0]) / size
;
296 if (ctx
->Point
.SpriteOrigin
== GL_LOWER_LEFT
)
297 t
= 0.5F
+ (y
+ 0.5F
- vert
->win
[1]) / size
;
298 else /* GL_UPPER_LEFT */
299 t
= 0.5F
- (y
+ 0.5F
- vert
->win
[1]) / size
;
300 span
->array
->texcoords
[u
][count
][0] = s
;
301 span
->array
->texcoords
[u
][count
][1] = t
;
302 span
->array
->texcoords
[u
][count
][3] = 1.0F
;
303 if (ctx
->Point
.SpriteRMode
== GL_ZERO
)
304 span
->array
->texcoords
[u
][count
][2] = 0.0F
;
305 else if (ctx
->Point
.SpriteRMode
== GL_S
)
306 span
->array
->texcoords
[u
][count
][2] = vert
->texcoord
[u
][0];
308 span
->array
->texcoords
[u
][count
][2] = vert
->texcoord
[u
][2];
311 COPY_4V(span
->array
->texcoords
[u
][count
], vert
->texcoord
[u
]);
317 count
++; /* square point */
326 #else /* LARGE | ATTENUATE | SMOOTH | SPRITE */
329 * Single-pixel points
334 /* check if we need to flush */
335 if (span
->end
>= MAX_WIDTH
||
336 (swrast
->_RasterMask
& (BLEND_BIT
| LOGIC_OP_BIT
| MASKING_BIT
))) {
337 #if FLAGS & (TEXTURE | SPRITE)
338 if (ctx
->Texture
._EnabledUnits
)
339 _swrast_write_texture_span(ctx
, span
);
341 _swrast_write_rgba_span(ctx
, span
);
343 _swrast_write_rgba_span(ctx
, span
);
345 _swrast_write_index_span(ctx
, span
);
353 span
->array
->rgba
[count
][RCOMP
] = red
;
354 span
->array
->rgba
[count
][GCOMP
] = green
;
355 span
->array
->rgba
[count
][BCOMP
] = blue
;
356 span
->array
->rgba
[count
][ACOMP
] = alpha
;
359 span
->array
->spec
[count
][RCOMP
] = specRed
;
360 span
->array
->spec
[count
][GCOMP
] = specGreen
;
361 span
->array
->spec
[count
][BCOMP
] = specBlue
;
364 span
->array
->index
[count
] = colorIndex
;
367 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
368 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
369 COPY_4V(span
->array
->texcoords
[u
][count
], texcoord
[u
]);
374 span
->array
->x
[count
] = (GLint
) vert
->win
[0];
375 span
->array
->y
[count
] = (GLint
) vert
->win
[1];
376 span
->array
->z
[count
] = (GLint
) (vert
->win
[2] + 0.5F
);
377 span
->end
= count
+ 1;
380 #endif /* LARGE || ATTENUATE || SMOOTH */
382 ASSERT(span
->end
<= MAX_WIDTH
);