New point rasterization functions based on template code that

handles CI/RGB, texture, antialiasing, attenuation, etc.

1 files changed, 312 insertions, 0 deletions

diff --git a/src/mesa/swrast/s_pointtemp.h b/src/mesa/swrast/s_pointtemp.h
new file mode 100644
index 00000000000..ed2ab0ca5e3
--- /dev/null
+++ b/src/mesa/swrast/s_pointtemp.h
@@ -0,0 +1,312 @@
+/* $Id: s_pointtemp.h,v 1.1 2001/01/03 22:17:16 brianp Exp $ */
+
+/*
+ * Mesa 3-D graphics library
+ * Version:  3.5
+ * 
+ * Copyright (C) 1999-2000  Brian Paul   All Rights Reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+/*
+ * Point rendering template code.
+ *
+ * Set FLAGS = bitwise-OR of the following tokens:
+ *
+ *   RGBA = do rgba instead of color index
+ *   SMOOTH = do antialiasing
+ *   TEXTURE = do texture coords
+ *   SPECULAR = do separate specular color
+ *   LARGE = do points with diameter > 1 pixel
+ *   ATTENUATE = compute point size attenuation
+ *   SPRITE = GL_MESA_sprite_point
+ *
+ * Notes: LARGE and ATTENUATE are exclusive of each other.
+ *        TEXTURE requires RGBA
+ *        SPECULAR requires TEXTURE
+ */
+
+
+/*
+ * NOTES on antialiased point rasterization:
+ *
+ * Let d = distance of fragment center from vertex.
+ * if d < rmin2 then
+ *    fragment has 100% coverage
+ * else if d > rmax2 then
+ *    fragment has 0% coverage
+ * else
+ *    fragement has % coverage = (d - rmin2) / (rmax2 - rmin2)
+ */
+
+
+
+static void
+NAME ( GLcontext *ctx, const SWvertex *vert )
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   struct pixel_buffer *PB = swrast->PB;
+
+   const GLint z = (GLint) (vert->win[2]);
+   const GLfixed fog = FloatToFixed( vert->fog );
+
+#if FLAGS & RGBA
+   const GLint red   = vert->color[0];
+   const GLint green = vert->color[1];
+   const GLint blue  = vert->color[2];
+   GLint alpha = vert->color[3];
+#if FLAGS & SPECULAR
+   const GLint sRed   = vert->specular[0];
+   const GLint sGreen = vert->specular[1];
+   const GLint sBlue  = vert->specular[2];
+#endif
+#else
+   GLint index = vert->index;
+#endif
+#if FLAGS & (ATTENUATE | LARGE | SMOOTH)
+   GLfloat size;
+#endif
+#if FLAGS & ATTENUATE
+   GLfloat alphaAtten;
+#endif
+
+#if FLAGS & TEXTURE
+   GLfloat texcoord[MAX_TEXTURE_UNITS][4];
+   GLuint u;
+   for (u = 0; u < ctx->Const.MaxTextureUnits; u++) {
+      if (ctx->Texture.Unit[u]._ReallyEnabled) {
+         if (vert->texcoord[u][3] != 1.0 && vert->texcoord[u][3] != 0.0) {
+            texcoord[u][0] = vert->texcoord[u][0] / vert->texcoord[u][3];
+            texcoord[u][1] = vert->texcoord[u][1] / vert->texcoord[u][3];
+            texcoord[u][2] = vert->texcoord[u][2] / vert->texcoord[u][3];
+         } 
+         else {
+            texcoord[u][0] = vert->texcoord[u][0];
+            texcoord[u][1] = vert->texcoord[u][1];
+            texcoord[u][2] = vert->texcoord[u][2];
+         }
+      }
+   }
+#endif
+
+#if FLAGS & ATTENUATE
+   if (vert->pointSize >= ctx->Point.Threshold) {
+      size = MIN2(vert->pointSize, ctx->Point.MaxSize);
+      alphaAtten = 1.0F;
+   }
+   else {
+      GLfloat dsize = vert->pointSize / ctx->Point.Threshold;
+      size = MAX2(ctx->Point.Threshold, ctx->Point.MinSize);
+      alphaAtten = dsize * dsize;
+   }
+#elif FLAGS & (LARGE | SMOOTH)
+   size = ctx->Point._Size;
+#endif
+
+#if FLAGS & SPRITE
+   {
+      SWcontext *swctx = SWRAST_CONTEXT(ctx);
+      const GLfloat radius = 0.5 * vert->pointSize;  /* XXX threshold, alpha */
+      SWvertex v0, v1, v2, v3;
+      GLuint unit;
+
+      (void) red;
+      (void) green;
+      (void) blue;
+      (void) alpha;
+      (void) fog;
+      (void) z;
+
+      /* lower left corner */
+      v0 = *vert;
+      v0.win[0] -= radius;
+      v0.win[1] -= radius;
+
+      /* lower right corner */
+      v1 = *vert;
+      v1.win[0] += radius;
+      v1.win[1] -= radius;
+
+      /* upper right corner */
+      v2 = *vert;
+      v2.win[0] += radius;
+      v2.win[1] += radius;
+
+      /* upper left corner */
+      v3 = *vert;
+      v3.win[0] -= radius;
+      v3.win[1] += radius;
+
+      for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
+         if (ctx->Texture.Unit[unit]._ReallyEnabled) {
+            v0.texcoord[unit][0] = 0.0;
+            v0.texcoord[unit][1] = 0.0;
+            v1.texcoord[unit][0] = 1.0;
+            v1.texcoord[unit][1] = 0.0;
+            v2.texcoord[unit][0] = 1.0;
+            v2.texcoord[unit][1] = 1.0;
+            v3.texcoord[unit][0] = 0.0;
+            v3.texcoord[unit][1] = 1.0;
+         }
+      }
+
+      /* XXX if radius < threshold, attenuate alpha? */
+
+      /* XXX need to implement clipping!!! */
+
+      /* render */
+      swctx->Triangle(ctx, &v0, &v1, &v2);
+      swctx->Triangle(ctx, &v0, &v2, &v3);
+   }
+
+#elif FLAGS & (LARGE | ATTENUATE | SMOOTH)
+
+   {
+      GLint x, y;
+      const GLfloat radius = 0.5F * size;
+#if FLAGS & SMOOTH
+      const GLfloat rmin = radius - 0.7071F;  /* 0.7071 = sqrt(2)/2 */
+      const GLfloat rmax = radius + 0.7071F;
+      const GLfloat rmin2 = MAX2(0.0, rmin * rmin);
+      const GLfloat rmax2 = rmax * rmax;
+      const GLfloat cscale = 256.0F / (rmax2 - rmin2);
+      const GLint xmin = (GLint) (vert->win[0] - radius);
+      const GLint xmax = (GLint) (vert->win[0] + radius);
+      const GLint ymin = (GLint) (vert->win[1] - radius);
+      const GLint ymax = (GLint) (vert->win[1] + radius);
+#else
+      /* non-smooth */
+      GLint xmin, xmax, ymin, ymax;
+      GLint iSize = (GLint) (size + 0.5F);
+      GLint iRadius;
+      iSize = MAX2(1, iSize);
+      iRadius = iSize / 2;
+      if (iSize & 1) {
+         /* odd size */
+         xmin = vert->win[0] - iRadius;
+         xmax = vert->win[0] + iRadius;
+         ymin = vert->win[1] - iRadius;
+         ymax = vert->win[1] + iRadius;
+      }
+      else {
+         /* even size */
+         xmin = (GLint) vert->win[0] - iRadius + 1;
+         xmax = xmin + iSize - 1;
+         ymin = (GLint) vert->win[1] - iRadius + 1;
+         ymax = ymin + iSize - 1;
+      }
+#endif
+      (void) radius;
+
+      for (y = ymin; y <= ymax; y++) {
+         for (x = xmin; x <= xmax; x++) {
+#if FLAGS & SMOOTH
+            /* compute coverage */
+            const GLfloat dx = x - vert->win[0];
+            const GLfloat dy = y - vert->win[1];
+            const GLfloat dist2 = dx * dx + dy * dy;
+            if (dist2 < rmax2) {
+               alpha = vert->color[3];
+               if (dist2 >= rmin2) {
+                  GLint coverage = (GLint) (256.0F - (dist2 - rmin2) * cscale);
+#if FLAGS & RGBA
+		  /* coverage is in [0,256] */
+		  alpha = (alpha * coverage) >> 8;
+#else
+                  /* 4 fractional index bits */
+                  index = (index & ~f) | (coverage >> 4);  /* XXX verify */
+#endif
+	       }
+#endif /* SMOOTH */
+
+#if ((FLAGS & (ATTENUATE | RGBA)) == (ATTENUATE | RGBA))
+	       alpha = (GLint) (alpha * alphaAtten);
+#endif
+
+#if FLAGS & SPECULAR
+               PB_WRITE_MULTITEX_SPEC_PIXEL(PB, x, y, z, fog,
+                                            red, green, blue, alpha,
+                                            sRed, sGreen, sBlue,
+                                            texcoord);
+
+#elif FLAGS & TEXTURE
+	       if (swrast->_MultiTextureEnabled) {
+		  PB_WRITE_MULTITEX_PIXEL(PB, x, y, z, fog,
+					  red, green, blue, alpha,
+					  texcoord);
+	       }
+	       else {
+		  PB_WRITE_TEX_PIXEL(PB, x,y,z, fog,
+				     red, green, blue, alpha,
+				     texcoord[0][0],
+				     texcoord[0][1],
+				     texcoord[0][2]);
+	       }
+#elif FLAGS & RGBA
+	       PB_WRITE_RGBA_PIXEL(PB, x, y, z, fog, red, green, blue, alpha);
+#else /* color index */
+               PB_WRITE_CI_PIXEL(PB, x, y, z, fog, index);
+#endif
+#if FLAGS & SMOOTH
+	    }
+#endif
+	 }
+      }
+      PB_CHECK_FLUSH(ctx,PB);
+   }
+
+#else /* LARGE || ATTENUATE || SMOOTH*/
+
+   {
+      /* size == 1 */
+      GLint x = vert->win[0];
+      GLint y = vert->win[1];
+#if ((FLAGS & (SPECULAR | TEXTURE)) == (SPECULAR | TEXTURE))
+      PB_WRITE_MULTITEX_SPEC_PIXEL(PB, x, y, z, fog,
+                                   red, green, blue, alpha,
+                                   sRed, sGreen, sBlue,
+                                   texcoord);
+#elif FLAGS & TEXTURE
+      if (swrast->_MultiTextureEnabled) {
+         PB_WRITE_MULTITEX_PIXEL(PB, x, y, z, fog,
+                                 red, green, blue, alpha, texcoord );
+      }
+      else {
+         PB_WRITE_TEX_PIXEL(PB, x, y, z, fog,
+                            red, green, blue, alpha,
+                            texcoord[0][0], texcoord[0][1], texcoord[0][2]);
+      }
+#elif FLAGS & RGBA
+      /* rgba size 1 point */
+      alpha = vert->color[3];
+      PB_WRITE_RGBA_PIXEL(PB, x, y, z, fog, red, green, blue, alpha);
+#else
+      /* color index size 1 point */
+      PB_WRITE_CI_PIXEL(PB, x, y, z, fog, index);
+#endif
+   }
+#endif /* LARGE || ATTENUATE || SMOOTH */
+
+   PB_CHECK_FLUSH(ctx, PB);
+}
+
+
+#undef FLAGS
+#undef NAME