line
plot
static void NAME() line	(	GLcontext *	ctx,
		const SWvertex *	v0,
		const SWvertex *	v1
	)		`[static]`
Definition at line 119 of file s_aalinetemp.h.
{
   SWcontext *swrast = SWRAST_CONTEXT(ctx);
   GLfloat tStart, tEnd;   /* segment start, end along line length */
   GLboolean inSegment;
   GLint iLen, i;

   /* Init the LineInfo struct */
   struct LineInfo line;
   line.x0 = v0->attrib[FRAG_ATTRIB_WPOS][0];
   line.y0 = v0->attrib[FRAG_ATTRIB_WPOS][1];
   line.x1 = v1->attrib[FRAG_ATTRIB_WPOS][0];
   line.y1 = v1->attrib[FRAG_ATTRIB_WPOS][1];
   line.dx = line.x1 - line.x0;
   line.dy = line.y1 - line.y0;
   line.len = SQRTF(line.dx * line.dx + line.dy * line.dy);
   line.halfWidth = 0.5F * CLAMP(ctx->Line.Width,
                                 ctx->Const.MinLineWidthAA,
                                 ctx->Const.MaxLineWidthAA);

   if (line.len == 0.0 || IS_INF_OR_NAN(line.len))
      return;

   INIT_SPAN(line.span, GL_LINE);
   line.span.arrayMask = SPAN_XY | SPAN_COVERAGE;
   line.span.facing = swrast->PointLineFacing;
   line.xAdj = line.dx / line.len * line.halfWidth;
   line.yAdj = line.dy / line.len * line.halfWidth;

#ifdef DO_Z
   line.span.arrayMask |= SPAN_Z;
   compute_plane(line.x0, line.y0, line.x1, line.y1,
                 v0->attrib[FRAG_ATTRIB_WPOS][2], v1->attrib[FRAG_ATTRIB_WPOS][2], line.zPlane);
#endif
#ifdef DO_RGBA
   line.span.arrayMask |= SPAN_RGBA;
   if (ctx->Light.ShadeModel == GL_SMOOTH) {
      compute_plane(line.x0, line.y0, line.x1, line.y1,
                    v0->color[RCOMP], v1->color[RCOMP], line.rPlane);
      compute_plane(line.x0, line.y0, line.x1, line.y1,
                    v0->color[GCOMP], v1->color[GCOMP], line.gPlane);
      compute_plane(line.x0, line.y0, line.x1, line.y1,
                    v0->color[BCOMP], v1->color[BCOMP], line.bPlane);
      compute_plane(line.x0, line.y0, line.x1, line.y1,
                    v0->color[ACOMP], v1->color[ACOMP], line.aPlane);
   }
   else {
      constant_plane(v1->color[RCOMP], line.rPlane);
      constant_plane(v1->color[GCOMP], line.gPlane);
      constant_plane(v1->color[BCOMP], line.bPlane);
      constant_plane(v1->color[ACOMP], line.aPlane);
   }
#endif
#ifdef DO_INDEX
   line.span.arrayMask |= SPAN_INDEX;
   if (ctx->Light.ShadeModel == GL_SMOOTH) {
      compute_plane(line.x0, line.y0, line.x1, line.y1,
                    v0->attrib[FRAG_ATTRIB_CI][0],
                    v1->attrib[FRAG_ATTRIB_CI][0], line.iPlane);
   }
   else {
      constant_plane(v1->attrib[FRAG_ATTRIB_CI][0], line.iPlane);
   }
#endif
#if defined(DO_ATTRIBS)
   {
      const GLfloat invW0 = v0->attrib[FRAG_ATTRIB_WPOS][3];
      const GLfloat invW1 = v1->attrib[FRAG_ATTRIB_WPOS][3];
      line.span.arrayMask |= SPAN_LAMBDA;
      compute_plane(line.x0, line.y0, line.x1, line.y1, invW0, invW1, line.wPlane);
      ATTRIB_LOOP_BEGIN
         GLuint c;
         if (swrast->_InterpMode[attr] == GL_FLAT) {
            for (c = 0; c < 4; c++) {
               constant_plane(v1->attrib[attr][c], line.attrPlane[attr][c]);
            }
         }
         else {
            for (c = 0; c < 4; c++) {
               const GLfloat a0 = v0->attrib[attr][c] * invW0;
               const GLfloat a1 = v1->attrib[attr][c] * invW1;
               compute_plane(line.x0, line.y0, line.x1, line.y1, a0, a1,
                             line.attrPlane[attr][c]);
            }
         }
         line.span.arrayAttribs |= (1 << attr);
         if (attr >= FRAG_ATTRIB_TEX0 && attr < FRAG_ATTRIB_VAR0) {
            const GLuint u = attr - FRAG_ATTRIB_TEX0;
            const struct gl_texture_object *obj = ctx->Texture.Unit[u]._Current;
            const struct gl_texture_image *texImage = obj->Image[0][obj->BaseLevel];
            line.texWidth[attr]  = (GLfloat) texImage->Width;
            line.texHeight[attr] = (GLfloat) texImage->Height;
         }
      ATTRIB_LOOP_END
   }
#endif

   tStart = tEnd = 0.0;
   inSegment = GL_FALSE;
   iLen = (GLint) line.len;

   if (ctx->Line.StippleFlag) {
      for (i = 0; i < iLen; i++) {
         const GLuint bit = (swrast->StippleCounter / ctx->Line.StippleFactor) & 0xf;
         if ((1 << bit) & ctx->Line.StipplePattern) {
            /* stipple bit is on */
            const GLfloat t = (GLfloat) i / (GLfloat) line.len;
            if (!inSegment) {
               /* start new segment */
               inSegment = GL_TRUE;
               tStart = t;
            }
            else {
               /* still in the segment, extend it */
               tEnd = t;
            }
         }
         else {
            /* stipple bit is off */
            if (inSegment && (tEnd > tStart)) {
               /* draw the segment */
               segment(ctx, &line, NAME(plot), tStart, tEnd);
               inSegment = GL_FALSE;
            }
            else {
               /* still between segments, do nothing */
            }
         }
         swrast->StippleCounter++;
      }

      if (inSegment) {
         /* draw the final segment of the line */
         segment(ctx, &line, NAME(plot), tStart, 1.0F);
      }
   }
   else {
      /* non-stippled */
      segment(ctx, &line, NAME(plot), 0.0, 1.0);
   }

#if defined(DO_RGBA)
   _swrast_write_rgba_span(ctx, &(line.span));
#else
   _swrast_write_index_span(ctx, &(line.span));
#endif
}
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