Fix stat computed by PC_Filter for scaled/offsetted dimensions.

Closes #78 (for 1.0 branch)
Includes testcase.

Author: Sandro Santilli

NEWS

@@ -3,6 +3,7 @@
 
 - Bug fixes
   - #79, Fix PC_Filter stats computation with dimensionally-compressed patches
+  - #78, Fix PC_Filter stats computation with scaled dimensions
   - #71, Fix crash in pc_schema_from_xml
   - #66, Fix crash in pc_schema_clone (unexploitable via SQL)
   - #37, Fix access to uninitialized variables

lib/pc_api_internal.h

@@ -233,6 +233,7 @@ uint32_t pc_bytes_sigbits_count_32(const PCBYTES *pcb, uint32_t *nsigbits);
 /** Using an 64-bit word, what is the common word and number of bits in common? */
 uint64_t pc_bytes_sigbits_count_64(const PCBYTES *pcb, uint32_t *nsigbits);
 
+/* NOTE: stats are gathered without applying scale and offset */
 PCBYTES pc_bytes_filter(const PCBYTES *pcb, const PCBITMAP *map, PCDOUBLESTAT *stats);
 
 PCBITMAP* pc_bytes_bitmap(const PCBYTES *pcb, PC_FILTERTYPE filter, double val1, double val2);

lib/pc_bytes.c

@@ -1305,6 +1305,7 @@ pc_bytes_minmax(const PCBYTES *pcb, double *min, double *max, double *avg)
 	return PC_FAILURE;
 }
 
+/* NOTE: stats are gathered without applying scale and offset */
 static PCBYTES
 pc_bytes_uncompressed_filter(const PCBYTES *pcb, const PCBITMAP *map, PCDOUBLESTAT *stats)
 {
@@ -1342,6 +1343,7 @@ pc_bytes_uncompressed_filter(const PCBYTES *pcb, const PCBITMAP *map, PCDOUBLEST
 	return fpcb;
 }
 
+/* NOTE: stats are gathered without applying scale and offset */
 static PCBYTES
 pc_bytes_run_length_filter(const PCBYTES *pcb, const PCBITMAP *map, PCDOUBLESTAT *stats)
 {
@@ -1405,6 +1407,7 @@ pc_bytes_run_length_filter(const PCBYTES *pcb, const PCBITMAP *map, PCDOUBLESTAT
 	return fpcb;
 }
 
+/* NOTE: stats are gathered without applying scale and offset */
 PCBYTES
 pc_bytes_filter(const PCBYTES *pcb, const PCBITMAP *map, PCDOUBLESTAT *stats)
 {

lib/pc_filter.c

@@ -151,12 +151,20 @@ pc_patch_dimensional_filter(const PCPATCH_DIMENSIONAL *pdl, const PCBITMAP *map)
 
 	for ( i = 0; i < pdl->schema->ndims; i++ )
 	{
+		PCDIMENSION *dim;
         PCDOUBLESTAT stats;
         stats.min = FLT_MAX;
         stats.max = -1*FLT_MAX;
         stats.sum = 0;
 		fpdl->bytes[i] = pc_bytes_filter(&(pdl->bytes[i]), map, &stats);
 
+
+		/* Apply scale and offset */
+		dim = pdl->schema->dims[i];
+		stats.min = pc_value_scale_offset(stats.min, dim);
+		stats.max = pc_value_scale_offset(stats.max, dim);
+		stats.sum = pc_value_scale_offset(stats.sum, dim);
+
 		/* Save the X/Y stats for use in bounds later */
 		if ( i == pdl->schema->x_position )
 		{

pgsql/expected/pointcloud.out

@@ -6,7 +6,7 @@ SELECT PC_Version();
 (1 row)
 
 INSERT INTO pointcloud_formats (pcid, srid, schema)
-VALUES (1, 0, 
+VALUES (1, 0, -- XYZI, scaled, uncompressed
 '<?xml version="1.0" encoding="UTF-8"?>
 <pc:PointCloudSchema xmlns:pc="http://pointcloud.org/schemas/PC/1.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <pc:dimension>
@@ -53,7 +53,7 @@ VALUES (1, 0,
   </pc:metadata>
 </pc:PointCloudSchema>'
 ),
-(3, 0,
+(3, 0, -- XYZI, scaled, dimensionally compressed
 '<?xml version="1.0" encoding="UTF-8"?>
 <pc:PointCloudSchema xmlns:pc="http://pointcloud.org/schemas/PC/1.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <pc:dimension>
@@ -338,4 +338,20 @@ FROM ( SELECT
  #79   |    -1 |    -1 |     0 |     0 |     1 |     1
 (1 row)
 
+-- https://github.com/pgpointcloud/pointcloud/issues/78
+SELECT '#78' issue,
+  PC_PatchMin(p,'x') x_min, PC_PatchMax(p,'x') x_max,
+  PC_PatchMin(p,'y') y_min, PC_PatchMax(p,'y') y_max,
+  PC_PatchMin(p,'z') z_min, PC_PatchMax(p,'z') z_max,
+  PC_PatchMin(p,'intensity') i_min, PC_PatchMax(p,'intensity') i_max
+FROM ( SELECT
+  PC_FilterEquals(
+    PC_Patch( PC_MakePoint(3,ARRAY[-1,0,4862413,1]) ),
+    'y',0) p
+) foo;
+ issue | x_min | x_max | y_min | y_max |  z_min  |  z_max  | i_min | i_max 
+-------+-------+-------+-------+-------+---------+---------+-------+-------
+ #78   |    -1 |    -1 |     0 |     0 | 4862413 | 4862413 |     1 |     1
+(1 row)
+
 TRUNCATE pointcloud_formats;

pgsql/sql/pointcloud.sql

@@ -3,7 +3,7 @@ CREATE EXTENSION pointcloud;
 SELECT PC_Version();
 
 INSERT INTO pointcloud_formats (pcid, srid, schema)
-VALUES (1, 0, 
+VALUES (1, 0, -- XYZI, scaled, uncompressed
 '<?xml version="1.0" encoding="UTF-8"?>
 <pc:PointCloudSchema xmlns:pc="http://pointcloud.org/schemas/PC/1.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <pc:dimension>
@@ -50,7 +50,7 @@ VALUES (1, 0,
   </pc:metadata>
 </pc:PointCloudSchema>'
 ),
-(3, 0,
+(3, 0, -- XYZI, scaled, dimensionally compressed
 '<?xml version="1.0" encoding="UTF-8"?>
 <pc:PointCloudSchema xmlns:pc="http://pointcloud.org/schemas/PC/1.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <pc:dimension>
@@ -213,4 +213,16 @@ FROM ( SELECT
     'y',0) p
 ) foo;
 
+-- https://github.com/pgpointcloud/pointcloud/issues/78
+SELECT '#78' issue,
+  PC_PatchMin(p,'x') x_min, PC_PatchMax(p,'x') x_max,
+  PC_PatchMin(p,'y') y_min, PC_PatchMax(p,'y') y_max,
+  PC_PatchMin(p,'z') z_min, PC_PatchMax(p,'z') z_max,
+  PC_PatchMin(p,'intensity') i_min, PC_PatchMax(p,'intensity') i_max
+FROM ( SELECT
+  PC_FilterEquals(
+    PC_Patch( PC_MakePoint(3,ARRAY[-1,0,4862413,1]) ),
+    'y',0) p
+) foo;
+
 TRUNCATE pointcloud_formats;