llvmpipe: (trivial) get rid of triangle subdivision code

This code was always problematic, and with 64bit rasterization we no longer
need it at all.

Reviewed-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>

3 files changed, 1 insertions, 182 deletions

diff --git a/src/gallium/drivers/llvmpipe/lp_setup.c b/src/gallium/drivers/llvmpipe/lp_setup.c
index 49962af7bb2..2fad469d197 100644
--- a/src/gallium/drivers/llvmpipe/lp_setup.c
+++ b/src/gallium/drivers/llvmpipe/lp_setup.c
@@ -1081,14 +1081,8 @@ try_update_scene_state( struct lp_setup_context *setup )
                                          &setup->draw_regions[i]);
          }
       }
-      /*
-       * Subdivide triangles if the framebuffer is larger than the
-       * MAX_FIXED_LENGTH.
-       */
-      setup->subdivide_large_triangles = (setup->fb.width > MAX_FIXED_LENGTH ||
-                                          setup->fb.height > MAX_FIXED_LENGTH);
    }
-                                      
+
    setup->dirty = 0;
 
    assert(setup->fs.stored);
diff --git a/src/gallium/drivers/llvmpipe/lp_setup_context.h b/src/gallium/drivers/llvmpipe/lp_setup_context.h
index 8bb95c15697..b3fb24ac497 100644
--- a/src/gallium/drivers/llvmpipe/lp_setup_context.h
+++ b/src/gallium/drivers/llvmpipe/lp_setup_context.h
@@ -93,7 +93,6 @@ struct lp_setup_context
    struct llvmpipe_query *active_queries[LP_MAX_ACTIVE_BINNED_QUERIES];
    unsigned active_binned_queries;
 
-   boolean subdivide_large_triangles;
    boolean flatshade_first;
    boolean ccw_is_frontface;
    boolean scissor_test;
diff --git a/src/gallium/drivers/llvmpipe/lp_setup_tri.c b/src/gallium/drivers/llvmpipe/lp_setup_tri.c
index e22f14c9ca0..ce3a0a76716 100644
--- a/src/gallium/drivers/llvmpipe/lp_setup_tri.c
+++ b/src/gallium/drivers/llvmpipe/lp_setup_tri.c
@@ -921,168 +921,6 @@ rotate_fixed_position_12( struct fixed_position* position )
 }
 
 
-typedef void (*triangle_func_t)(struct lp_setup_context *setup,
-                                const float (*v0)[4],
-                                const float (*v1)[4],
-                                const float (*v2)[4]);
-
-
-/**
- * Subdivide this triangle by bisecting edge (v0, v1).
- * \param pv  the provoking vertex (must = v0 or v1 or v2)
- * TODO: should probably think about non-overflowing arithmetic elsewhere.
- * This will definitely screw with pipeline counters for instance.
- */
-static void
-subdiv_tri(struct lp_setup_context *setup,
-           const float (*v0)[4],
-           const float (*v1)[4],
-           const float (*v2)[4],
-           const float (*pv)[4],
-           triangle_func_t tri)
-{
-   unsigned n = setup->fs.current.variant->shader->info.base.num_inputs + 1;
-   const struct lp_shader_input *inputs =
-      setup->fs.current.variant->shader->inputs;
-   PIPE_ALIGN_VAR(LP_MIN_VECTOR_ALIGN) float vmid[PIPE_MAX_ATTRIBS][4];
-   const float (*vm)[4] = (const float (*)[4]) vmid;
-   unsigned i;
-   float w0, w1, wm;
-   boolean flatshade = setup->fs.current.variant->key.flatshade;
-
-   /* find position midpoint (attrib[0] = position) */
-   vmid[0][0] = 0.5f * (v1[0][0] + v0[0][0]);
-   vmid[0][1] = 0.5f * (v1[0][1] + v0[0][1]);
-   vmid[0][2] = 0.5f * (v1[0][2] + v0[0][2]);
-   vmid[0][3] = 0.5f * (v1[0][3] + v0[0][3]);
-
-   w0 = v0[0][3];
-   w1 = v1[0][3];
-   wm = vmid[0][3];
-
-   /* interpolate other attributes */
-   for (i = 1; i < n; i++) {
-      if ((inputs[i - 1].interp == LP_INTERP_COLOR && flatshade) ||
-          inputs[i - 1].interp == LP_INTERP_CONSTANT) {
-         /* copy the provoking vertex's attribute */
-         vmid[i][0] = pv[i][0];
-         vmid[i][1] = pv[i][1];
-         vmid[i][2] = pv[i][2];
-         vmid[i][3] = pv[i][3];
-      }
-      else {
-         /* interpolate with perspective correction (for linear too) */
-         vmid[i][0] = 0.5f * (v1[i][0] * w1 + v0[i][0] * w0) / wm;
-         vmid[i][1] = 0.5f * (v1[i][1] * w1 + v0[i][1] * w0) / wm;
-         vmid[i][2] = 0.5f * (v1[i][2] * w1 + v0[i][2] * w0) / wm;
-         vmid[i][3] = 0.5f * (v1[i][3] * w1 + v0[i][3] * w0) / wm;
-      }
-   }
-
-   /* handling flat shading and first vs. last provoking vertex is a
-    * little tricky...
-    */
-   if (pv == v0) {
-      if (setup->flatshade_first) {
-         /* first vertex must be v0 or vm */
-         tri(setup, v0, vm, v2);
-         tri(setup, vm, v1, v2);
-      }
-      else {
-         /* last vertex must be v0 or vm */
-         tri(setup, vm, v2, v0);
-         tri(setup, v1, v2, vm);
-      }
-   }
-   else if (pv == v1) {
-      if (setup->flatshade_first) {
-         tri(setup, vm, v2, v0);
-         tri(setup, v1, v2, vm);
-      }
-      else {
-         tri(setup, v2, v0, vm);
-         tri(setup, v2, vm, v1);
-      }
-   }
-   else {
-      if (setup->flatshade_first) {
-         tri(setup, v2, v0, vm);
-         tri(setup, v2, vm, v1);
-      }
-      else {
-         tri(setup, v0, vm, v2);
-         tri(setup, vm, v1, v2);
-      }
-   }
-}
-
-
-/**
- * Check the lengths of the edges of the triangle.  If any edge is too
- * long, subdivide the longest edge and draw two sub-triangles.
- * Note: this may be called recursively.
- * \return TRUE if triangle was subdivided, FALSE otherwise
- */
-static boolean
-check_subdivide_triangle(struct lp_setup_context *setup,
-                         const float (*v0)[4],
-                         const float (*v1)[4],
-                         const float (*v2)[4],
-                         triangle_func_t tri)
-{
-   const float maxLen = (float) MAX_FIXED_LENGTH;  /* longest permissible edge, in pixels */
-   float dx10, dy10, len10;
-   float dx21, dy21, len21;
-   float dx02, dy02, len02;
-   const float (*pv)[4] = setup->flatshade_first ? v0 : v2;
-
-   /* compute lengths of triangle edges, squared */
-   dx10 = v1[0][0] - v0[0][0];
-   dy10 = v1[0][1] - v0[0][1];
-   len10 = dx10 * dx10 + dy10 * dy10;
-
-   dx21 = v2[0][0] - v1[0][0];
-   dy21 = v2[0][1] - v1[0][1];
-   len21 = dx21 * dx21 + dy21 * dy21;
-
-   dx02 = v0[0][0] - v2[0][0];
-   dy02 = v0[0][1] - v2[0][1];
-   len02 = dx02 * dx02 + dy02 * dy02;
-
-   /* Look for longest the edge that's longer than maxLen.  If we find
-    * such an edge, split the triangle using the midpoint of that edge.
-    * Note: it's important to split the longest edge, not just any edge
-    * that's longer than maxLen.  Otherwise, we can get into a degenerate
-    * situation and recurse indefinitely.
-    */
-   if (len10 > maxLen * maxLen &&
-       len10 >= len21 &&
-       len10 >= len02) {
-      /* subdivide v0, v1 edge */
-      subdiv_tri(setup, v0, v1, v2, pv, tri);
-      return TRUE;
-   }
-
-   if (len21 > maxLen * maxLen &&
-       len21 >= len10 &&
-       len21 >= len02) {       
-      /* subdivide v1, v2 edge */
-      subdiv_tri(setup, v1, v2, v0, pv, tri);
-      return TRUE;
-   }
-
-   if (len02 > maxLen * maxLen &&
-       len02 >= len21 &&
-       len02 >= len10) {       
-      /* subdivide v2, v0 edge */
-      subdiv_tri(setup, v2, v0, v1, pv, tri);
-      return TRUE;
-   }
-
-   return FALSE;
-}
-
-
 /**
  * Draw triangle if it's CW, cull otherwise.
  */
@@ -1093,10 +931,6 @@ static void triangle_cw( struct lp_setup_context *setup,
 {
    struct fixed_position position;
 
-   if (setup->subdivide_large_triangles &&
-       check_subdivide_triangle(setup, v0, v1, v2, triangle_cw))
-      return;
-
    calc_fixed_position(setup, &position, v0, v1, v2);
 
    if (position.area < 0) {
@@ -1118,10 +952,6 @@ static void triangle_ccw( struct lp_setup_context *setup,
 {
    struct fixed_position position;
 
-   if (setup->subdivide_large_triangles &&
-       check_subdivide_triangle(setup, v0, v1, v2, triangle_ccw))
-      return;
-
    calc_fixed_position(setup, &position, v0, v1, v2);
 
    if (position.area > 0)
@@ -1139,10 +969,6 @@ static void triangle_both( struct lp_setup_context *setup,
    struct fixed_position position;
    struct llvmpipe_context *lp_context = (struct llvmpipe_context *)setup->pipe;
 
-   if (setup->subdivide_large_triangles &&
-       check_subdivide_triangle(setup, v0, v1, v2, triangle_both))
-      return;
-
    if (lp_context->active_statistics_queries &&
        !llvmpipe_rasterization_disabled(lp_context)) {
       lp_context->pipeline_statistics.c_primitives++;