Git conversion: Make reactos the root directory, move rosapps, rostests, wallpapers into modules, and delete rossubsys.

dll/opengl/mesa/swrast/s_aatriangle.c

@@ -0,0 +1,285 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  6.5.3
+ *
+ * Copyright (C) 1999-2007  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.
+ */
+
+
+/*
+ * Antialiased Triangle rasterizers
+ */
+
+#include <precomp.h>
+
+/*
+ * Compute coefficients of a plane using the X,Y coords of the v0, v1, v2
+ * vertices and the given Z values.
+ * A point (x,y,z) lies on plane iff a*x+b*y+c*z+d = 0.
+ */
+static inline void
+compute_plane(const GLfloat v0[], const GLfloat v1[], const GLfloat v2[],
+              GLfloat z0, GLfloat z1, GLfloat z2, GLfloat plane[4])
+{
+   const GLfloat px = v1[0] - v0[0];
+   const GLfloat py = v1[1] - v0[1];
+   const GLfloat pz = z1 - z0;
+
+   const GLfloat qx = v2[0] - v0[0];
+   const GLfloat qy = v2[1] - v0[1];
+   const GLfloat qz = z2 - z0;
+
+   /* Crossproduct "(a,b,c):= dv1 x dv2" is orthogonal to plane. */
+   const GLfloat a = py * qz - pz * qy;
+   const GLfloat b = pz * qx - px * qz;
+   const GLfloat c = px * qy - py * qx;
+   /* Point on the plane = "r*(a,b,c) + w", with fixed "r" depending
+      on the distance of plane from origin and arbitrary "w" parallel
+      to the plane. */
+   /* The scalar product "(r*(a,b,c)+w)*(a,b,c)" is "r*(a^2+b^2+c^2)",
+      which is equal to "-d" below. */
+   const GLfloat d = -(a * v0[0] + b * v0[1] + c * z0);
+
+   plane[0] = a;
+   plane[1] = b;
+   plane[2] = c;
+   plane[3] = d;
+}
+
+
+/*
+ * Compute coefficients of a plane with a constant Z value.
+ */
+static inline void
+constant_plane(GLfloat value, GLfloat plane[4])
+{
+   plane[0] = 0.0;
+   plane[1] = 0.0;
+   plane[2] = -1.0;
+   plane[3] = value;
+}
+
+#define CONSTANT_PLANE(VALUE, PLANE)	\
+do {					\
+   PLANE[0] = 0.0F;			\
+   PLANE[1] = 0.0F;			\
+   PLANE[2] = -1.0F;			\
+   PLANE[3] = VALUE;			\
+} while (0)
+
+
+
+/*
+ * Solve plane equation for Z at (X,Y).
+ */
+static inline GLfloat
+solve_plane(GLfloat x, GLfloat y, const GLfloat plane[4])
+{
+   ASSERT(plane[2] != 0.0F);
+   return (plane[3] + plane[0] * x + plane[1] * y) / -plane[2];
+}
+
+
+#define SOLVE_PLANE(X, Y, PLANE) \
+   ((PLANE[3] + PLANE[0] * (X) + PLANE[1] * (Y)) / -PLANE[2])
+
+/*
+ * Solve plane and return clamped GLchan value.
+ */
+static inline GLchan
+solve_plane_chan(GLfloat x, GLfloat y, const GLfloat plane[4])
+{
+   const GLfloat z = (plane[3] + plane[0] * x + plane[1] * y) / -plane[2];
+#if CHAN_TYPE == GL_FLOAT
+   return CLAMP(z, 0.0F, CHAN_MAXF);
+#else
+   if (z < 0)
+      return 0;
+   else if (z > CHAN_MAX)
+      return CHAN_MAX;
+   return (GLchan) IROUND_POS(z);
+#endif
+}
+
+
+static inline GLfloat
+plane_dx(const GLfloat plane[4])
+{
+   return -plane[0] / plane[2];
+}
+
+static inline GLfloat
+plane_dy(const GLfloat plane[4])
+{
+   return -plane[1] / plane[2];
+}
+
+
+
+/*
+ * Compute how much (area) of the given pixel is inside the triangle.
+ * Vertices MUST be specified in counter-clockwise order.
+ * Return:  coverage in [0, 1].
+ */
+static GLfloat
+compute_coveragef(const GLfloat v0[3], const GLfloat v1[3],
+                  const GLfloat v2[3], GLint winx, GLint winy)
+{
+   /* Given a position [0,3]x[0,3] return the sub-pixel sample position.
+    * Contributed by Ray Tice.
+    *
+    * Jitter sample positions -
+    * - average should be .5 in x & y for each column
+    * - each of the 16 rows and columns should be used once
+    * - the rectangle formed by the first four points
+    *   should contain the other points
+    * - the distrubition should be fairly even in any given direction
+    *
+    * The pattern drawn below isn't optimal, but it's better than a regular
+    * grid.  In the drawing, the center of each subpixel is surrounded by
+    * four dots.  The "x" marks the jittered position relative to the
+    * subpixel center.
+    */
+#define POS(a, b) (0.5+a*4+b)/16
+   static const GLfloat samples[16][2] = {
+      /* start with the four corners */
+      { POS(0, 2), POS(0, 0) },
+      { POS(3, 3), POS(0, 2) },
+      { POS(0, 0), POS(3, 1) },
+      { POS(3, 1), POS(3, 3) },
+      /* continue with interior samples */
+      { POS(1, 1), POS(0, 1) },
+      { POS(2, 0), POS(0, 3) },
+      { POS(0, 3), POS(1, 3) },
+      { POS(1, 2), POS(1, 0) },
+      { POS(2, 3), POS(1, 2) },
+      { POS(3, 2), POS(1, 1) },
+      { POS(0, 1), POS(2, 2) },
+      { POS(1, 0), POS(2, 1) },
+      { POS(2, 1), POS(2, 3) },
+      { POS(3, 0), POS(2, 0) },
+      { POS(1, 3), POS(3, 0) },
+      { POS(2, 2), POS(3, 2) }
+   };
+
+   const GLfloat x = (GLfloat) winx;
+   const GLfloat y = (GLfloat) winy;
+   const GLfloat dx0 = v1[0] - v0[0];
+   const GLfloat dy0 = v1[1] - v0[1];
+   const GLfloat dx1 = v2[0] - v1[0];
+   const GLfloat dy1 = v2[1] - v1[1];
+   const GLfloat dx2 = v0[0] - v2[0];
+   const GLfloat dy2 = v0[1] - v2[1];
+   GLint stop = 4, i;
+   GLfloat insideCount = 16.0F;
+
+   ASSERT(dx0 * dy1 - dx1 * dy0 >= 0.0); /* area >= 0.0 */
+
+   for (i = 0; i < stop; i++) {
+      const GLfloat sx = x + samples[i][0];
+      const GLfloat sy = y + samples[i][1];
+      /* cross product determines if sample is inside or outside each edge */
+      GLfloat cross = (dx0 * (sy - v0[1]) - dy0 * (sx - v0[0]));
+      /* Check if the sample is exactly on an edge.  If so, let cross be a
+       * positive or negative value depending on the direction of the edge.
+       */
+      if (cross == 0.0F)
+         cross = dx0 + dy0;
+      if (cross < 0.0F) {
+         /* sample point is outside first edge */
+         insideCount -= 1.0F;
+         stop = 16;
+      }
+      else {
+         /* sample point is inside first edge */
+         cross = (dx1 * (sy - v1[1]) - dy1 * (sx - v1[0]));
+         if (cross == 0.0F)
+            cross = dx1 + dy1;
+         if (cross < 0.0F) {
+            /* sample point is outside second edge */
+            insideCount -= 1.0F;
+            stop = 16;
+         }
+         else {
+            /* sample point is inside first and second edges */
+            cross = (dx2 * (sy - v2[1]) -  dy2 * (sx - v2[0]));
+            if (cross == 0.0F)
+               cross = dx2 + dy2;
+            if (cross < 0.0F) {
+               /* sample point is outside third edge */
+               insideCount -= 1.0F;
+               stop = 16;
+            }
+         }
+      }
+   }
+   if (stop == 4)
+      return 1.0F;
+   else
+      return insideCount * (1.0F / 16.0F);
+}
+
+
+
+static void
+rgba_aa_tri(struct gl_context *ctx,
+	    const SWvertex *v0,
+	    const SWvertex *v1,
+	    const SWvertex *v2)
+{
+#define DO_Z
+#include "s_aatritemp.h"
+}
+
+
+static void
+general_aa_tri(struct gl_context *ctx,
+               const SWvertex *v0,
+               const SWvertex *v1,
+               const SWvertex *v2)
+{
+#define DO_Z
+#define DO_ATTRIBS
+#include "s_aatritemp.h"
+}
+
+
+
+/*
+ * Examine GL state and set swrast->Triangle to an
+ * appropriate antialiased triangle rasterizer function.
+ */
+void
+_swrast_set_aa_triangle_function(struct gl_context *ctx)
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+
+   ASSERT(ctx->Polygon.SmoothFlag);
+
+   if (ctx->Texture._EnabledCoord
+       || swrast->_FogEnabled) {
+      SWRAST_CONTEXT(ctx)->Triangle = general_aa_tri;
+   }
+   else {
+      SWRAST_CONTEXT(ctx)->Triangle = rgba_aa_tri;
+   }
+
+   ASSERT(SWRAST_CONTEXT(ctx)->Triangle);
+}