[Bf-blender-cvs] [9852c6cf631] temp-T96710-pbvh-pixels: Only store 2 components of barycentric coordinates.

[Jeroen Bakker]

Commit: 9852c6cf631567782d3ea018bfe5097accefb3d0
Author: Jeroen Bakker
Date:   Fri Apr 15 12:00:02 2022 +0200
Branches: temp-T96710-pbvh-pixels
https://developer.blender.org/rB9852c6cf631567782d3ea018bfe5097accefb3d0

Only store 2 components of barycentric coordinates.

===================================================================

M	source/blender/blenkernel/BKE_pbvh_pixels.hh
M	source/blender/blenkernel/intern/pbvh_pixels.cc
M	source/blender/editors/sculpt_paint/sculpt_paint_image.cc

===================================================================

diff --git a/source/blender/blenkernel/BKE_pbvh_pixels.hh b/source/blender/blenkernel/BKE_pbvh_pixels.hh
index dbfc03dd12a..35eb340d0a1 100644
--- a/source/blender/blenkernel/BKE_pbvh_pixels.hh
+++ b/source/blender/blenkernel/BKE_pbvh_pixels.hh
@@ -25,20 +25,16 @@ struct TrianglePaintInput {
    *
    * Only the first two coordinates are stored. The third should be recalculated
    */
-  float3 delta_barycentric_coord_u;
-  /** Delta barycentric coordinates between 2 neighbouring UV's in the V direction. */
-  float3 delta_barycentric_coord_v;
+  float2 delta_barycentric_coord_u;
 
   /**
    * Initially only the vert indices are known.
    *
-   * delta_barycentric_coord_u/v are initialized in a later stage as it requires image tile
+   * delta_barycentric_coord_u is initialized in a later stage as it requires image tile
    * dimensions.
    */
   TrianglePaintInput(const int3 vert_indices)
-      : vert_indices(vert_indices),
-        delta_barycentric_coord_u(0.0f, 0.0f, 0.0f),
-        delta_barycentric_coord_v(0.0f, 0.0f, 0.0f)
+      : vert_indices(vert_indices), delta_barycentric_coord_u(0.0f, 0.0f)
   {
   }
 };
@@ -90,7 +86,7 @@ struct Triangles {
  */
 struct PackedPixelRow {
   /** Barycentric coordinate of the first pixel. */
-  float3 start_barycentric_coord;
+  float2 start_barycentric_coord;
   /** Image coordinate starting of the first pixel. */
   ushort2 start_image_coordinate;
   /** Number of sequential pixels encoded in this package. */
diff --git a/source/blender/blenkernel/intern/pbvh_pixels.cc b/source/blender/blenkernel/intern/pbvh_pixels.cc
index 07da012f619..d8dd2f4b382 100644
--- a/source/blender/blenkernel/intern/pbvh_pixels.cc
+++ b/source/blender/blenkernel/intern/pbvh_pixels.cc
@@ -29,7 +29,7 @@ constexpr bool USE_WATERTIGHT_CHECK = false;
 /**
  * Calculate the delta of two neighbour uv coordinates in the given image buffer.
  */
-static float3 calc_barycentric_delta(const float2 uvs[3],
+static float2 calc_barycentric_delta(const float2 uvs[3],
                                      const float2 start_uv,
                                      const float2 end_uv)
 {
@@ -38,10 +38,11 @@ static float3 calc_barycentric_delta(const float2 uvs[3],
   barycentric_weights_v2(uvs[0], uvs[1], uvs[2], start_uv, start_barycentric);
   float3 end_barycentric;
   barycentric_weights_v2(uvs[0], uvs[1], uvs[2], end_uv, end_barycentric);
-  return end_barycentric - start_barycentric;
+  float3 barycentric = end_barycentric - start_barycentric;
+  return float2(barycentric.x, barycentric.y);
 }
 
-static float3 calc_barycentric_delta_x(const ImBuf *image_buffer,
+static float2 calc_barycentric_delta_x(const ImBuf *image_buffer,
                                        const float2 uvs[3],
                                        const int x,
                                        const int y)
@@ -51,16 +52,6 @@ static float3 calc_barycentric_delta_x(const ImBuf *image_buffer,
   return calc_barycentric_delta(uvs, start_uv, end_uv);
 }
 
-static float3 calc_barycentric_delta_y(const ImBuf *image_buffer,
-                                       const float2 uvs[3],
-                                       const int x,
-                                       const int y)
-{
-  const float2 start_uv(float(x) / image_buffer->x, float(y) / image_buffer->y);
-  const float2 end_uv(float(x) / image_buffer->x, float(y + 1) / image_buffer->y);
-  return calc_barycentric_delta(uvs, start_uv, end_uv);
-}
-
 static void extract_barycentric_pixels(UDIMTilePixels &tile_data,
                                        const ImBuf *image_buffer,
                                        const int triangle_index,
@@ -86,7 +77,7 @@ static void extract_barycentric_pixels(UDIMTilePixels &tile_data,
       if (!start_detected && is_inside) {
         start_detected = true;
         pixel_row.start_image_coordinate = ushort2(x, y);
-        pixel_row.start_barycentric_coord = barycentric_weights;
+        pixel_row.start_barycentric_coord = float2(barycentric_weights.x, barycentric_weights.y);
       }
       else if (start_detected && !is_inside) {
         break;
@@ -159,7 +150,6 @@ static void do_encode_pixels(void *__restrict userdata,
 
       TrianglePaintInput &triangle = triangles.get_paint_input(triangle_index);
       triangle.delta_barycentric_coord_u = calc_barycentric_delta_x(image_buffer, uvs, minx, miny);
-      triangle.delta_barycentric_coord_v = calc_barycentric_delta_y(image_buffer, uvs, minx, miny);
       extract_barycentric_pixels(
           tile_data, image_buffer, triangle_index, uvs, minx, miny, maxx, maxy);
     }
diff --git a/source/blender/editors/sculpt_paint/sculpt_paint_image.cc b/source/blender/editors/sculpt_paint/sculpt_paint_image.cc
index da8758b1f20..082ff6260c2 100644
--- a/source/blender/editors/sculpt_paint/sculpt_paint_image.cc
+++ b/source/blender/editors/sculpt_paint/sculpt_paint_image.cc
@@ -247,15 +247,18 @@ template<typename ImageBuffer> class PaintingKernel {
   }
 
   float3 init_pixel_pos(const TrianglePaintInput &triangle,
-                        const float3 &barycentric_weights) const
+                        const float2 &barycentric_weights) const
   {
     const int3 &vert_indices = triangle.vert_indices;
     float3 result;
+    const float3 barycentric(barycentric_weights.x,
+                             barycentric_weights.y,
+                             1.0f - barycentric_weights.x - barycentric_weights.y);
     interp_v3_v3v3v3(result,
                      mvert[vert_indices[0]].co,
                      mvert[vert_indices[1]].co,
                      mvert[vert_indices[2]].co,
-                     barycentric_weights);
+                     barycentric);
     return result;
   }
 };