s_lines.c revision 7117f1b4 
1/*
2 * Mesa 3-D graphics library
3 * Version:  6.5.3
4 *
5 * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
6 *
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:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
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.
23 */
24
25
26#include "glheader.h"
27#include "context.h"
28#include "colormac.h"
29#include "macros.h"
30#include "s_aaline.h"
31#include "s_context.h"
32#include "s_depth.h"
33#include "s_feedback.h"
34#include "s_lines.h"
35#include "s_span.h"
36
37
38/*
39 * Init the mask[] array to implement a line stipple.
40 */
41static void
42compute_stipple_mask( GLcontext *ctx, GLuint len, GLubyte mask[] )
43{
44   SWcontext *swrast = SWRAST_CONTEXT(ctx);
45   GLuint i;
46
47   for (i = 0; i < len; i++) {
48      GLuint bit = (swrast->StippleCounter / ctx->Line.StippleFactor) & 0xf;
49      if ((1 << bit) & ctx->Line.StipplePattern) {
50         mask[i] = GL_TRUE;
51      }
52      else {
53         mask[i] = GL_FALSE;
54      }
55      swrast->StippleCounter++;
56   }
57}
58
59
60/*
61 * To draw a wide line we can simply redraw the span N times, side by side.
62 */
63static void
64draw_wide_line( GLcontext *ctx, SWspan *span, GLboolean xMajor )
65{
66   GLint width, start;
67
68   ASSERT(span->end < MAX_WIDTH);
69
70   width = (GLint) CLAMP( ctx->Line._Width, MIN_LINE_WIDTH, MAX_LINE_WIDTH );
71
72   if (width & 1)
73      start = width / 2;
74   else
75      start = width / 2 - 1;
76
77   if (xMajor) {
78      GLint *y = span->array->y;
79      GLuint i;
80      GLint w;
81      for (w = 0; w < width; w++) {
82         if (w == 0) {
83            for (i = 0; i < span->end; i++)
84               y[i] -= start;
85         }
86         else {
87            for (i = 0; i < span->end; i++)
88               y[i]++;
89         }
90         if (ctx->Visual.rgbMode)
91            _swrast_write_rgba_span(ctx, span);
92         else
93            _swrast_write_index_span(ctx, span);
94      }
95   }
96   else {
97      GLint *x = span->array->x;
98      GLuint i;
99      GLint w;
100      for (w = 0; w < width; w++) {
101         if (w == 0) {
102            for (i = 0; i < span->end; i++)
103               x[i] -= start;
104         }
105         else {
106            for (i = 0; i < span->end; i++)
107               x[i]++;
108         }
109         if (ctx->Visual.rgbMode)
110            _swrast_write_rgba_span(ctx, span);
111         else
112            _swrast_write_index_span(ctx, span);
113      }
114   }
115}
116
117
118
119/**********************************************************************/
120/*****                    Rasterization                           *****/
121/**********************************************************************/
122
123/* Simple color index line (no stipple, width=1, no Z, no fog, no tex)*/
124#define NAME simple_ci_line
125#define INTERP_INDEX
126#define RENDER_SPAN(span) _swrast_write_index_span(ctx, &span)
127#include "s_linetemp.h"
128
129/* Simple RGBA index line (no stipple, width=1, no Z, no fog, no tex)*/
130#define NAME simple_rgba_line
131#define INTERP_RGBA
132#define RENDER_SPAN(span) _swrast_write_rgba_span(ctx, &span);
133#include "s_linetemp.h"
134
135
136/* Z, fog, wide, stipple color index line */
137#define NAME general_ci_line
138#define INTERP_INDEX
139#define INTERP_Z
140#define INTERP_FOG
141#define RENDER_SPAN(span)					\
142   if (ctx->Line.StippleFlag) {					\
143      span.arrayMask |= SPAN_MASK;				\
144      compute_stipple_mask(ctx, span.end, span.array->mask);    \
145   }								\
146   if (ctx->Line._Width > 1.0) {					\
147      draw_wide_line(ctx, &span, (GLboolean)(dx > dy));		\
148   }								\
149   else {							\
150      _swrast_write_index_span(ctx, &span);			\
151   }
152#include "s_linetemp.h"
153
154
155/* Z, fog, wide, stipple RGBA line */
156#define NAME general_rgba_line
157#define INTERP_RGBA
158#define INTERP_Z
159#define INTERP_FOG
160#define RENDER_SPAN(span)					\
161   if (ctx->Line.StippleFlag) {					\
162      span.arrayMask |= SPAN_MASK;				\
163      compute_stipple_mask(ctx, span.end, span.array->mask);	\
164   }								\
165   if (ctx->Line._Width > 1.0) {					\
166      draw_wide_line(ctx, &span, (GLboolean)(dx > dy));		\
167   }								\
168   else {							\
169      _swrast_write_rgba_span(ctx, &span);			\
170   }
171#include "s_linetemp.h"
172
173
174/* General-purpose textured line (any/all features). */
175#define NAME textured_line
176#define INTERP_RGBA
177#define INTERP_SPEC
178#define INTERP_Z
179#define INTERP_FOG
180#define INTERP_ATTRIBS
181#define RENDER_SPAN(span)					\
182   if (ctx->Line.StippleFlag) {					\
183      span.arrayMask |= SPAN_MASK;				\
184      compute_stipple_mask(ctx, span.end, span.array->mask);	\
185   }								\
186   if (ctx->Line._Width > 1.0) {					\
187      draw_wide_line(ctx, &span, (GLboolean)(dx > dy));		\
188   }								\
189   else {							\
190      _swrast_write_rgba_span(ctx, &span);			\
191   }
192#include "s_linetemp.h"
193
194
195
196void
197_swrast_add_spec_terms_line( GLcontext *ctx,
198                             const SWvertex *v0,
199                             const SWvertex *v1 )
200{
201   SWvertex *ncv0 = (SWvertex *)v0;
202   SWvertex *ncv1 = (SWvertex *)v1;
203   GLchan c[2][4];
204   COPY_CHAN4( c[0], ncv0->color );
205   COPY_CHAN4( c[1], ncv1->color );
206   ACC_3V( ncv0->color, ncv0->specular );
207   ACC_3V( ncv1->color, ncv1->specular );
208   SWRAST_CONTEXT(ctx)->SpecLine( ctx, ncv0, ncv1 );
209   COPY_CHAN4( ncv0->color, c[0] );
210   COPY_CHAN4( ncv1->color, c[1] );
211}
212
213
214#ifdef DEBUG
215extern void
216_mesa_print_line_function(GLcontext *ctx);  /* silence compiler warning */
217void
218_mesa_print_line_function(GLcontext *ctx)
219{
220   SWcontext *swrast = SWRAST_CONTEXT(ctx);
221
222   _mesa_printf("Line Func == ");
223   if (swrast->Line == simple_ci_line)
224      _mesa_printf("simple_ci_line\n");
225   else if (swrast->Line == simple_rgba_line)
226      _mesa_printf("simple_rgba_line\n");
227   else if (swrast->Line == general_ci_line)
228      _mesa_printf("general_ci_line\n");
229   else if (swrast->Line == general_rgba_line)
230      _mesa_printf("general_rgba_line\n");
231   else if (swrast->Line == textured_line)
232      _mesa_printf("textured_line\n");
233   else
234      _mesa_printf("Driver func %p\n", (void *(*)()) swrast->Line);
235}
236#endif
237
238
239
240#ifdef DEBUG
241
242/* record the current line function name */
243static const char *lineFuncName = NULL;
244
245#define USE(lineFunc)                   \
246do {                                    \
247    lineFuncName = #lineFunc;           \
248    /*_mesa_printf("%s\n", lineFuncName);*/   \
249    swrast->Line = lineFunc;            \
250} while (0)
251
252#else
253
254#define USE(lineFunc)  swrast->Line = lineFunc
255
256#endif
257
258
259
260/*
261 * Determine which line drawing function to use given the current
262 * rendering context.
263 *
264 * Please update the summary flag _SWRAST_NEW_LINE if you add or remove
265 * tests to this code.
266 */
267void
268_swrast_choose_line( GLcontext *ctx )
269{
270   SWcontext *swrast = SWRAST_CONTEXT(ctx);
271   const GLboolean rgbmode = ctx->Visual.rgbMode;
272
273   if (ctx->RenderMode == GL_RENDER) {
274      if (ctx->Line.SmoothFlag) {
275         /* antialiased lines */
276         _swrast_choose_aa_line_function(ctx);
277         ASSERT(swrast->Line);
278      }
279      else if (ctx->Texture._EnabledCoordUnits
280             || ctx->FragmentProgram._Current) {
281         /* textured lines */
282         USE(textured_line);
283      }
284      else if (ctx->Depth.Test || swrast->_FogEnabled || ctx->Line._Width != 1.0
285               || ctx->Line.StippleFlag) {
286         /* no texture, but Z, fog, width>1, stipple, etc. */
287         if (rgbmode)
288            USE(general_rgba_line);
289         else
290            USE(general_ci_line);
291      }
292      else {
293         /* simplest lines */
294         if (rgbmode)
295            USE(simple_rgba_line);
296         else
297            USE(simple_ci_line);
298      }
299   }
300   else if (ctx->RenderMode == GL_FEEDBACK) {
301      USE(_swrast_feedback_line);
302   }
303   else {
304      ASSERT(ctx->RenderMode == GL_SELECT);
305      USE(_swrast_select_line);
306   }
307
308   /*_mesa_print_line_function(ctx);*/
309}
310