llvmpipe: native point rasterization

Conflicts:

	src/gallium/drivers/llvmpipe/lp_setup_context.h
	src/gallium/drivers/llvmpipe/lp_setup_line.c
	src/gallium/drivers/llvmpipe/lp_setup_tri.c

1 files changed, 222 insertions, 3 deletions

diff --git a/src/gallium/drivers/llvmpipe/lp_setup_point.c b/src/gallium/drivers/llvmpipe/lp_setup_point.c
index 709c3e2fd2..07a28fc6e3 100644
--- a/src/gallium/drivers/llvmpipe/lp_setup_point.c
+++ b/src/gallium/drivers/llvmpipe/lp_setup_point.c
@@ -1,6 +1,6 @@
 /**************************************************************************
  *
- * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * Copyright 2010, VMware Inc.
  * All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
@@ -18,7 +18,7 @@
  * 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 NON-INFRINGEMENT.
- * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS 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.
@@ -30,10 +30,229 @@
  */
 
 #include "lp_setup_context.h"
+#include "util/u_math.h"
+#include "util/u_memory.h"
+#include "lp_perf.h"
+#include "lp_setup_context.h"
+#include "lp_rast.h"
+#include "lp_state_fs.h"
+
+#define NUM_CHANNELS 4
+
+struct point_info {
+   /* x,y deltas */
+   int dy01, dy12;
+   int dx01, dx12;
+
+   const float (*v0)[4];
+};   
+
+
+/**
+ * Compute a0 for a constant-valued coefficient (GL_FLAT shading).
+ */
+static void constant_coef( struct lp_setup_context *setup,
+                           struct lp_rast_triangle *point,
+                           unsigned slot,
+                           const float value,
+                           unsigned i )
+{
+   point->inputs.a0[slot][i] = value;
+   point->inputs.dadx[slot][i] = 0.0f;
+   point->inputs.dady[slot][i] = 0.0f;
+}
+
+/**
+ * Special coefficient setup for gl_FragCoord.
+ * X and Y are trivial
+ * Z and W are copied from position_coef which should have already been computed.
+ * We could do a bit less work if we'd examine gl_FragCoord's swizzle mask.
+ */
+static void
+setup_point_fragcoord_coef(struct lp_setup_context *setup,
+                           struct lp_rast_triangle *point,
+                           const struct point_info *info,
+                           unsigned slot,
+                           unsigned usage_mask)
+{
+   /*X*/
+   if (usage_mask & TGSI_WRITEMASK_X) {
+      point->inputs.a0[slot][0] = 0.0;
+      point->inputs.dadx[slot][0] = 1.0;
+      point->inputs.dady[slot][0] = 0.0;
+   }
+
+   /*Y*/
+   if (usage_mask & TGSI_WRITEMASK_Y) {
+      point->inputs.a0[slot][1] = 0.0;
+      point->inputs.dadx[slot][1] = 0.0;
+      point->inputs.dady[slot][1] = 1.0;
+   }
+
+   /*Z*/
+   if (usage_mask & TGSI_WRITEMASK_Z) {
+      constant_coef(setup, point, slot, info->v0[0][2], 2);
+   }
+
+   /*W*/
+   if (usage_mask & TGSI_WRITEMASK_W) {
+      constant_coef(setup, point, slot, info->v0[0][3], 3);
+   }
+}
+
+/**
+ * Compute the point->coef[] array dadx, dady, a0 values.
+ */
+static void   
+setup_point_coefficients( struct lp_setup_context *setup,
+                          struct lp_rast_triangle *point,
+                          const struct point_info *info)
+{
+   unsigned fragcoord_usage_mask = TGSI_WRITEMASK_XYZ;
+   unsigned slot;
+
+   /* setup interpolation for all the remaining attributes:
+    */
+   for (slot = 0; slot < setup->fs.nr_inputs; slot++) {
+      unsigned vert_attr = setup->fs.input[slot].src_index;
+      unsigned usage_mask = setup->fs.input[slot].usage_mask;
+      unsigned i;
+      
+      switch (setup->fs.input[slot].interp) {
+      case LP_INTERP_POSITION:
+         /*
+          * The generated pixel interpolators will pick up the coeffs from
+          * slot 0, so all need to ensure that the usage mask is covers all
+          * usages.
+          */
+         fragcoord_usage_mask |= usage_mask;
+         break;
+
+      default:
+         for (i = 0; i < NUM_CHANNELS; i++) {
+            if (usage_mask & (1 << i))
+               constant_coef(setup, point, slot+1, info->v0[vert_attr][i], i);
+         }
+      }
+   }
+
+   /* The internal position input is in slot zero:
+    */
+   setup_point_fragcoord_coef(setup, point, info, 0,
+                              fragcoord_usage_mask);
+}
+
+static INLINE int
+subpixel_snap(float a)
+{
+   return util_iround(FIXED_ONE * a);
+}
+
 
 static void lp_setup_point( struct lp_setup_context *setup,
-                       const float (*v0)[4] )
+                            const float (*v0)[4] )
 {
+   /* x/y positions in fixed point */
+   const int sizeAttr = setup->psize;
+   const float size
+      = sizeAttr > 0 ? v0[sizeAttr][0]
+      : setup->point_size;
+   const float half_width = 0.5F * size;
+ 
+   const int x0 = subpixel_snap(v0[0][0] - half_width - setup->pixel_offset);
+   const int x1 = subpixel_snap(v0[0][0] - half_width - setup->pixel_offset);
+   const int x2 = subpixel_snap(v0[0][0] + half_width - setup->pixel_offset);
+   const int y0 = subpixel_snap(v0[0][1] - half_width - setup->pixel_offset);
+   const int y1 = subpixel_snap(v0[0][1] + half_width - setup->pixel_offset);
+   const int y2 = subpixel_snap(v0[0][1] + half_width - setup->pixel_offset);
+   struct lp_scene *scene = lp_setup_get_current_scene(setup);
+   struct lp_rast_triangle *point;
+   unsigned bytes;
+   struct u_rect bbox;
+   unsigned nr_planes = 4;
+   struct point_info info;
+
+
+   /* Bounding rectangle (in pixels) */
+   {
+      /* Yes this is necessary to accurately calculate bounding boxes
+       * with the two fill-conventions we support.  GL (normally) ends
+       * up needing a bottom-left fill convention, which requires
+       * slightly different rounding.
+       */
+      int adj = (setup->pixel_offset != 0) ? 1 : 0;
+
+      bbox.x0 = (MIN3(x0, x1, x2) + (FIXED_ONE-1)) >> FIXED_ORDER;
+      bbox.x1 = (MAX3(x0, x1, x2) + (FIXED_ONE-1)) >> FIXED_ORDER;
+      bbox.y0 = (MIN3(y0, y1, y2) + (FIXED_ONE-1) + adj) >> FIXED_ORDER;
+      bbox.y1 = (MAX3(y0, y1, y2) + (FIXED_ONE-1) + adj) >> FIXED_ORDER;
+
+      /* Inclusive coordinates:
+       */
+      bbox.x1--;
+      bbox.y1--;
+   }
+   
+   if (!u_rect_test_intersection(&setup->draw_region, &bbox)) {
+      if (0) debug_printf("offscreen\n");
+      LP_COUNT(nr_culled_tris);
+      return;
+   }
+
+   u_rect_find_intersection(&setup->draw_region, &bbox);
+
+   point = lp_setup_alloc_triangle(scene,
+                                   setup->fs.nr_inputs,
+                                   nr_planes,
+                                   &bytes);
+   if (!point)
+      return;
+
+#ifdef DEBUG
+   point->v[0][0] = v0[0][0];
+   point->v[0][1] = v0[0][1];
+#endif
+
+   info.v0 = v0;
+   info.dx01 = x1 - x0;
+   info.dx12 = x2 - x1;
+   info.dy01 = y1 - y0;
+   info.dy12 = y2 - y1;
+   
+   /* Setup parameter interpolants:
+    */
+   setup_point_coefficients(setup, point, &info);
+
+   point->inputs.facing = 1.0F;
+   point->inputs.state = setup->fs.stored;
+
+   {
+      point->plane[0].dcdx = -1;
+      point->plane[0].dcdy = 0;
+      point->plane[0].c = 1-bbox.x0;
+      point->plane[0].ei = 0;
+      point->plane[0].eo = 1;
+
+      point->plane[1].dcdx = 1;
+      point->plane[1].dcdy = 0;
+      point->plane[1].c = bbox.x1+1;
+      point->plane[1].ei = -1;
+      point->plane[1].eo = 0;
+
+      point->plane[2].dcdx = 0;
+      point->plane[2].dcdy = 1;
+      point->plane[2].c = 1-bbox.y0;
+      point->plane[2].ei = 0;
+      point->plane[2].eo = 1;
+
+      point->plane[3].dcdx = 0;
+      point->plane[3].dcdy = -1;
+      point->plane[3].c = bbox.y1+1;
+      point->plane[3].ei = -1;
+      point->plane[3].eo = 0;
+   }
+
+   lp_setup_bin_triangle(setup, point, &bbox, nr_planes);
 }