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_no_z_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_no_z_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 ci_line
 138 #define INTERP_INDEX
 139 #define INTERP_Z
 140 #define INTERP_ATTRIBS /* for 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 rgba_line
 157 #define INTERP_RGBA
 158 #define INTERP_Z
 159 #define RENDER_SPAN(span)                                       \
 160    if (ctx->Line.StippleFlag) {                                 \
 161       span.arrayMask |= SPAN_MASK;                              \
 162       compute_stipple_mask(ctx, span.end, span.array->mask);    \
 163    }                                                            \
 164    if (ctx->Line._Width > 1.0) {                                \
 165       draw_wide_line(ctx, &span, (GLboolean)(dx > dy));         \
 166    }                                                            \
 167    else {                                                       \
 168       _swrast_write_rgba_span(ctx, &span);                      \
 169    }
 170 #include "s_linetemp.h"
 171
 172
 173 /* General-purpose line (any/all features). */
 174 #define NAME general_line
 175 #define INTERP_RGBA
 176 #define INTERP_Z
 177 #define INTERP_ATTRIBS
 178 #define RENDER_SPAN(span)                                       \
 179    if (ctx->Line.StippleFlag) {                                 \
 180       span.arrayMask |= SPAN_MASK;                              \
 181       compute_stipple_mask(ctx, span.end, span.array->mask);    \
 182    }                                                            \
 183    if (ctx->Line._Width > 1.0) {                                \
 184       draw_wide_line(ctx, &span, (GLboolean)(dx > dy));         \
 185    }                                                            \
 186    else {                                                       \
 187       _swrast_write_rgba_span(ctx, &span);                      \
 188    }
 189 #include "s_linetemp.h"
 190
 191
 192
 193 void
 194 _swrast_add_spec_terms_line(GLcontext *ctx,
 195                             const SWvertex *v0, const SWvertex *v1)
 196 {
 197    SWvertex *ncv0 = (SWvertex *)v0;
 198    SWvertex *ncv1 = (SWvertex *)v1;
 199    GLfloat rSum, gSum, bSum;
 200    GLchan cSave[2][4];
 201
 202    /* save original colors */
 203    COPY_CHAN4(cSave[0], ncv0->color);
 204    COPY_CHAN4(cSave[1], ncv1->color);
 205    /* sum v0 */
 206    rSum = CHAN_TO_FLOAT(ncv0->color[0]) + ncv0->attrib[FRAG_ATTRIB_COL1][0];
 207    gSum = CHAN_TO_FLOAT(ncv0->color[1]) + ncv0->attrib[FRAG_ATTRIB_COL1][1];
 208    bSum = CHAN_TO_FLOAT(ncv0->color[2]) + ncv0->attrib[FRAG_ATTRIB_COL1][2];
 209    UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[0], rSum);
 210    UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[1], gSum);
 211    UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[2], bSum);
 212    /* sum v1 */
 213    rSum = CHAN_TO_FLOAT(ncv1->color[0]) + ncv1->attrib[FRAG_ATTRIB_COL1][0];
 214    gSum = CHAN_TO_FLOAT(ncv1->color[1]) + ncv1->attrib[FRAG_ATTRIB_COL1][1];
 215    bSum = CHAN_TO_FLOAT(ncv1->color[2]) + ncv1->attrib[FRAG_ATTRIB_COL1][2];
 216    UNCLAMPED_FLOAT_TO_CHAN(ncv1->color[0], rSum);
 217    UNCLAMPED_FLOAT_TO_CHAN(ncv1->color[1], gSum);
 218    UNCLAMPED_FLOAT_TO_CHAN(ncv1->color[2], bSum);
 219    /* draw */
 220    SWRAST_CONTEXT(ctx)->SpecLine( ctx, ncv0, ncv1 );
 221    /* restore original colors */
 222    COPY_CHAN4( ncv0->attrib[FRAG_ATTRIB_COL0], cSave[0] );
 223    COPY_CHAN4( ncv1->attrib[FRAG_ATTRIB_COL0], cSave[1] );
 224 }
 225
 226
 227
 228 #ifdef DEBUG
 229
 230 /* record the current line function name */
 231 static const char *lineFuncName = NULL;
 232
 233 #define USE(lineFunc)                   \
 234 do {                                    \
 235     lineFuncName = #lineFunc;           \
 236     /*_mesa_printf("%s\n", lineFuncName);*/   \
 237     swrast->Line = lineFunc;            \
 238 } while (0)
 239
 240 #else
 241
 242 #define USE(lineFunc)  swrast->Line = lineFunc
 243
 244 #endif
 245
 246
 247
 248 /**
 249  * Determine which line drawing function to use given the current
 250  * rendering context.
 251  *
 252  * Please update the summary flag _SWRAST_NEW_LINE if you add or remove
 253  * tests to this code.
 254  */
 255 void
 256 _swrast_choose_line( GLcontext *ctx )
 257 {
 258    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 259    const GLboolean rgbmode = ctx->Visual.rgbMode;
 260    GLboolean specular = (ctx->Fog.ColorSumEnabled ||
 261                          (ctx->Light.Enabled &&
 262                           ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR));
 263
 264    if (ctx->RenderMode == GL_RENDER) {
 265       if (ctx->Line.SmoothFlag) {
 266          /* antialiased lines */
 267          _swrast_choose_aa_line_function(ctx);
 268          ASSERT(swrast->Line);
 269       }
 270       else if (ctx->Texture._EnabledCoordUnits
 271                || ctx->FragmentProgram._Current
 272                || swrast->_FogEnabled
 273                || specular) {
 274          USE(general_line);
 275       }
 276       else if (ctx->Depth.Test
 277                || ctx->Line._Width != 1.0
 278                || ctx->Line.StippleFlag) {
 279          /* no texture, but Z, fog, width>1, stipple, etc. */
 280          if (rgbmode)
 281             USE(rgba_line);
 282          else
 283             USE(ci_line);
 284       }
 285       else {
 286          ASSERT(!ctx->Depth.Test);
 287          /* simple lines */
 288          if (rgbmode)
 289             USE(simple_no_z_rgba_line);
 290          else
 291             USE(simple_no_z_ci_line);
 292       }
 293    }
 294    else if (ctx->RenderMode == GL_FEEDBACK) {
 295       USE(_swrast_feedback_line);
 296    }
 297    else {
 298       ASSERT(ctx->RenderMode == GL_SELECT);
 299       USE(_swrast_select_line);
 300    }
 301 }