src/mesa/swrast/s_lines.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5
   4  *
   5  * Copyright (C) 1999-2005  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 /* Single-texture line, w/ fog, Z, specular, etc. */
 175 #define NAME textured_line
 176 #define INTERP_RGBA
 177 #define INTERP_Z
 178 #define INTERP_FOG
 179 #define INTERP_TEX
 180 #define RENDER_SPAN(span)                                       \
 181    if (ctx->Line.StippleFlag) {                                 \
 182       span.arrayMask |= SPAN_MASK;                              \
 183       compute_stipple_mask(ctx, span.end, span.array->mask);    \
 184    }                                                            \
 185    if (ctx->Line._Width > 1.0) {                                        \
 186       draw_wide_line(ctx, &span, (GLboolean)(dx > dy));         \
 187    }                                                            \
 188    else {                                                       \
 189       _swrast_write_rgba_span(ctx, &span);                      \
 190    }
 191 #include "s_linetemp.h"
 192
 193
 194 /* Multi-texture or separate specular line, w/ fog, Z, specular, etc. */
 195 #define NAME multitextured_line
 196 #define INTERP_RGBA
 197 #define INTERP_SPEC
 198 #define INTERP_Z
 199 #define INTERP_FOG
 200 #define INTERP_MULTITEX
 201 #define INTERP_VARYING
 202 #define RENDER_SPAN(span)                                       \
 203    if (ctx->Line.StippleFlag) {                                 \
 204       span.arrayMask |= SPAN_MASK;                              \
 205       compute_stipple_mask(ctx, span.end, span.array->mask);    \
 206    }                                                            \
 207    if (ctx->Line._Width > 1.0) {                                        \
 208       draw_wide_line(ctx, &span, (GLboolean)(dx > dy));         \
 209    }                                                            \
 210    else {                                                       \
 211       _swrast_write_rgba_span(ctx, &span);                      \
 212    }
 213 #include "s_linetemp.h"
 214
 215
 216
 217 void
 218 _swrast_add_spec_terms_line( GLcontext *ctx,
 219                              const SWvertex *v0,
 220                              const SWvertex *v1 )
 221 {
 222    SWvertex *ncv0 = (SWvertex *)v0;
 223    SWvertex *ncv1 = (SWvertex *)v1;
 224    GLchan c[2][4];
 225    COPY_CHAN4( c[0], ncv0->color );
 226    COPY_CHAN4( c[1], ncv1->color );
 227    ACC_3V( ncv0->color, ncv0->specular );
 228    ACC_3V( ncv1->color, ncv1->specular );
 229    SWRAST_CONTEXT(ctx)->SpecLine( ctx, ncv0, ncv1 );
 230    COPY_CHAN4( ncv0->color, c[0] );
 231    COPY_CHAN4( ncv1->color, c[1] );
 232 }
 233
 234
 235 #ifdef DEBUG
 236 extern void
 237 _mesa_print_line_function(GLcontext *ctx);  /* silence compiler warning */
 238 void
 239 _mesa_print_line_function(GLcontext *ctx)
 240 {
 241    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 242
 243    _mesa_printf("Line Func == ");
 244    if (swrast->Line == simple_ci_line)
 245       _mesa_printf("simple_ci_line\n");
 246    else if (swrast->Line == simple_rgba_line)
 247       _mesa_printf("simple_rgba_line\n");
 248    else if (swrast->Line == general_ci_line)
 249       _mesa_printf("general_ci_line\n");
 250    else if (swrast->Line == general_rgba_line)
 251       _mesa_printf("general_rgba_line\n");
 252    else if (swrast->Line == textured_line)
 253       _mesa_printf("textured_line\n");
 254    else if (swrast->Line == multitextured_line)
 255       _mesa_printf("multitextured_line\n");
 256    else
 257       _mesa_printf("Driver func %p\n", (void *(*)()) swrast->Line);
 258 }
 259 #endif
 260
 261
 262
 263 #ifdef DEBUG
 264
 265 /* record the current line function name */
 266 static const char *lineFuncName = NULL;
 267
 268 #define USE(lineFunc)                   \
 269 do {                                    \
 270     lineFuncName = #lineFunc;           \
 271     /*_mesa_printf("%s\n", lineFuncName);*/   \
 272     swrast->Line = lineFunc;            \
 273 } while (0)
 274
 275 #else
 276
 277 #define USE(lineFunc)  swrast->Line = lineFunc
 278
 279 #endif
 280
 281
 282
 283 /*
 284  * Determine which line drawing function to use given the current
 285  * rendering context.
 286  *
 287  * Please update the summary flag _SWRAST_NEW_LINE if you add or remove
 288  * tests to this code.
 289  */
 290 void
 291 _swrast_choose_line( GLcontext *ctx )
 292 {
 293    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 294    const GLboolean rgbmode = ctx->Visual.rgbMode;
 295
 296    if (ctx->RenderMode == GL_RENDER) {
 297       if (ctx->Line.SmoothFlag) {
 298          /* antialiased lines */
 299          _swrast_choose_aa_line_function(ctx);
 300          ASSERT(swrast->Line);
 301       }
 302       else if (ctx->Texture._EnabledCoordUnits
 303              || ctx->FragmentProgram._Current) {
 304          /* textured lines */
 305          if (ctx->Texture._EnabledCoordUnits > 0x1
 306              || NEED_SECONDARY_COLOR(ctx)
 307              || ctx->FragmentProgram._Current) {
 308             /* multi-texture and/or separate specular color */
 309             USE(multitextured_line);
 310          }
 311          else {
 312             USE(textured_line);
 313          }
 314       }
 315       else if (ctx->Depth.Test || swrast->_FogEnabled || ctx->Line._Width != 1.0
 316                || ctx->Line.StippleFlag) {
 317          /* no texture, but Z, fog, width>1, stipple, etc. */
 318          if (rgbmode)
 319             USE(general_rgba_line);
 320          else
 321             USE(general_ci_line);
 322       }
 323       else {
 324          /* simplest lines */
 325          if (rgbmode)
 326             USE(simple_rgba_line);
 327          else
 328             USE(simple_ci_line);
 329       }
 330    }
 331    else if (ctx->RenderMode == GL_FEEDBACK) {
 332       USE(_swrast_feedback_line);
 333    }
 334    else {
 335       ASSERT(ctx->RenderMode == GL_SELECT);
 336       USE(_swrast_select_line);
 337    }
 338
 339    /*_mesa_print_line_function(ctx);*/
 340 }