src/mesa/swrast/s_lines.c

   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  */
  41 static void
  42 compute_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  */
  63 static void
  64 draw_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
 196 void
 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
 215 extern void
 216 _mesa_print_line_function(GLcontext *ctx);  /* silence compiler warning */
 217 void
 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 */
 243 static const char *lineFuncName = NULL;
 244
 245 #define USE(lineFunc)                   \
 246 do {                                    \
 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  */
 267 void
 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 }