cockroachdb · craig · Jun 4, 2020 · Jun 4, 2020
@@ -927,7 +927,7 @@ BUILD_TAGGED_RELEASE =
 ## Override for .buildinfo/tag
 BUILDINFO_TAG :=
 
-$(go-targets): bin/.bootstrap $(BUILDINFO) $(CGO_FLAGS_FILES) $(PROTOBUF_TARGETS)
+$(go-targets): bin/.bootstrap $(BUILDINFO) $(CGO_FLAGS_FILES) $(PROTOBUF_TARGETS) $(LIBPROJ)
 $(go-targets): $(SQLPARSER_TARGETS) $(EXECGEN_TARGETS) $(OPTGEN_TARGETS)
 $(go-targets): override LINKFLAGS += \
 	-X "github.com/cockroachdb/cockroach/pkg/build.tag=$(if $(BUILDINFO_TAG),$(BUILDINFO_TAG),$(shell cat .buildinfo/tag))" \
@@ -1715,7 +1715,7 @@ logictest-bins := bin/logictest bin/logictestopt bin/logictestccl
 # Additional dependencies for binaries that depend on generated code.
 #
 # TODO(benesch): Derive this automatically. This is getting out of hand.
-bin/workload bin/docgen bin/execgen bin/roachtest $(logictest-bins): $(SQLPARSER_TARGETS) $(PROTOBUF_TARGETS)
+bin/workload bin/docgen bin/execgen bin/roachtest $(logictest-bins): $(LIBPROJ) $(CGO_FLAGS_FILES) $(SQLPARSER_TARGETS) $(PROTOBUF_TARGETS)
 bin/workload bin/roachtest $(logictest-bins): $(EXECGEN_TARGETS)
 bin/roachtest $(logictest-bins): $(C_LIBS_CCL) $(CGO_FLAGS_FILES) $(OPTGEN_TARGETS)
 

diff --git a/docs/generated/sql/functions.md b/docs/generated/sql/functions.md
@@ -1075,6 +1075,18 @@ has no relationship with the commit order of concurrent transactions.</p>
 <p>This function utilizes the GEOS module.</p>
 <p>This function will automatically use any available index.</p>
 </span></td></tr>
+<tr><td><a name="st_transform"></a><code>st_transform(geometry: geometry, from_proj_text: <a href="string.html">string</a>, srid: <a href="int.html">int</a>) &rarr; geometry</code></td><td><span class="funcdesc"><p>Transforms a geometry into the coordinate reference system assuming the from_proj_text to the new to_proj_text by projecting its coordinates. The supplied SRID is set on the new geometry.</p>
+<p>This function utilizes the PROJ library for coordinate projections.</p>
+</span></td></tr>
+<tr><td><a name="st_transform"></a><code>st_transform(geometry: geometry, from_proj_text: <a href="string.html">string</a>, to_proj_text: <a href="string.html">string</a>) &rarr; geometry</code></td><td><span class="funcdesc"><p>Transforms a geometry into the coordinate reference system assuming the from_proj_text to the new to_proj_text by projecting its coordinates.</p>
+<p>This function utilizes the PROJ library for coordinate projections.</p>
+</span></td></tr>
+<tr><td><a name="st_transform"></a><code>st_transform(geometry: geometry, srid: <a href="int.html">int</a>) &rarr; geometry</code></td><td><span class="funcdesc"><p>Transforms a geometry into the given SRID coordinate reference system by projecting its coordinates.</p>
+<p>This function utilizes the PROJ library for coordinate projections.</p>
+</span></td></tr>
+<tr><td><a name="st_transform"></a><code>st_transform(geometry: geometry, to_proj_text: <a href="string.html">string</a>) &rarr; geometry</code></td><td><span class="funcdesc"><p>Transforms a geometry into the coordinate reference system referenced by the projection text by projecting its coordinates.</p>
+<p>This function utilizes the PROJ library for coordinate projections.</p>
+</span></td></tr>
 <tr><td><a name="st_within"></a><code>st_within(geometry_a: geometry, geometry_b: geometry) &rarr; <a href="bool.html">bool</a></code></td><td><span class="funcdesc"><p>Returns true if geometry_a is completely inside geometry_b.</p>
 <p>This function utilizes the GEOS module.</p>
 <p>This function will automatically use any available index.</p>

@@ -0,0 +1,109 @@
+---
+Language:        Cpp
+AccessModifierOffset: -1
+AlignAfterOpenBracket: Align
+AlignConsecutiveAssignments: false
+AlignConsecutiveDeclarations: false
+AlignEscapedNewlines: Right
+AlignOperands:   true
+AlignTrailingComments: true
+AllowAllParametersOfDeclarationOnNextLine: true
+AllowShortBlocksOnASingleLine: false
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: All
+AllowShortIfStatementsOnASingleLine: false
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterDefinitionReturnType: None
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: false
+AlwaysBreakTemplateDeclarations: false
+BinPackArguments: true
+BinPackParameters: true
+BraceWrapping:
+  AfterClass:      false
+  AfterControlStatement: false
+  AfterEnum:       false
+  AfterFunction:   false
+  AfterNamespace:  false
+  AfterObjCDeclaration: false
+  AfterStruct:     false
+  AfterUnion:      false
+  BeforeCatch:     false
+  BeforeElse:      false
+  IndentBraces:    false
+  SplitEmptyFunction: true
+  SplitEmptyRecord: true
+  SplitEmptyNamespace: true
+BreakBeforeBinaryOperators: None
+BreakBeforeBraces: Attach
+BreakBeforeInheritanceComma: false
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializersBeforeComma: false
+BreakConstructorInitializers: BeforeColon
+BreakAfterJavaFieldAnnotations: false
+BreakStringLiterals: true
+ColumnLimit:     100
+CommentPragmas:  '^ IWYU pragma:'
+CompactNamespaces: false
+ConstructorInitializerAllOnOneLineOrOnePerLine: true
+ConstructorInitializerIndentWidth: 4
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: true
+DerivePointerAlignment: false
+DisableFormat:   false
+ExperimentalAutoDetectBinPacking: false
+FixNamespaceComments: true
+ForEachMacros:
+  - foreach
+  - Q_FOREACH
+  - BOOST_FOREACH
+IncludeCategories:
+  - Regex:           '^"(llvm|llvm-c|clang|clang-c)/'
+    Priority:        2
+  - Regex:           '^(<|"(gtest|isl|json)/)'
+    Priority:        3
+  - Regex:           '^".*"$'
+    Priority:        4
+  - Regex:           '.*'
+    Priority:        5
+IncludeIsMainRegex: '(Test)?$'
+IndentCaseLabels: false
+IndentWidth:     2
+IndentWrappedFunctionNames: false
+JavaScriptQuotes: Leave
+JavaScriptWrapImports: true
+KeepEmptyLinesAtTheStartOfBlocks: true
+MacroBlockBegin: ''
+MacroBlockEnd:   ''
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: None
+ObjCBlockIndentWidth: 2
+ObjCSpaceAfterProperty: false
+ObjCSpaceBeforeProtocolList: true
+PenaltyBreakAssignment: 2
+PenaltyBreakBeforeFirstCallParameter: 19
+PenaltyBreakComment: 300
+PenaltyBreakFirstLessLess: 120
+PenaltyBreakString: 1000
+PenaltyExcessCharacter: 1000000
+PenaltyReturnTypeOnItsOwnLine: 60
+PointerAlignment: Left
+ReflowComments:  true
+SortIncludes:    true
+SortUsingDeclarations: true
+SpaceAfterCStyleCast: false
+SpaceAfterTemplateKeyword: true
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeParens: ControlStatements
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 2
+SpacesInAngles:  false
+SpacesInContainerLiterals: true
+SpacesInCStyleCastParentheses: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+Standard:        Cpp11
+TabWidth:        8
+UseTab:          Never
+...
+
@@ -18,28 +18,55 @@ package geoproj
 // #cgo windows LDFLAGS: -lshlwapi -lrpcrt4
 //
 // #include "proj.h"
-// #include <proj_api.h>
 import "C"
-import "unsafe"
+import (
+	"unsafe"
 
-// ProjPJ is the projPJ wrapper around the PROJ library's projPJ object.
-type ProjPJ struct {
-	projPJ C.projPJ
-}
+	"github.com/cockroachdb/cockroach/pkg/geo/geoprojbase"
+	"github.com/cockroachdb/errors"
+)
+
+// maxArrayLen is the maximum safe length for this architecture.
+const maxArrayLen = 1<<31 - 1
 
-// IsLatLng returns whether the underlying ProjPJ is a latlng system.
-// TODO(otan): store this metadata in the projPJ struct.
-func (p *ProjPJ) IsLatLng() bool {
-	return C.pj_is_latlong(p.projPJ) != 0
+func cStatusToUnsafeGoBytes(s C.CR_PROJ_Status) []byte {
+	if s.data == nil {
+		return nil
+	}
+	// Interpret the C pointer as a pointer to a Go array, then slice.
+	return (*[maxArrayLen]byte)(unsafe.Pointer(s.data))[:s.len:s.len]
 }
 
-// NewProjPJFromText initializes a ProjPJ from text.
-// TODO(otan): thread through thread contexts and retrieve error messages.
-// TODO(otan): use slice management mechanisms.
-// TODO(otan): free after creation.
-func NewProjPJFromText(proj4text string) (*ProjPJ, error) {
-	str := C.CString(proj4text)
-	defer C.free(unsafe.Pointer(str))
-	projPJ := C.pj_init_plus(str)
-	return &ProjPJ{projPJ: projPJ}, nil
+// Project projects the given xCoords, yCoords and zCoords from one
+// coordinate system to another using proj4text.
+// Array elements are edited in place.
+func Project(
+	from geoprojbase.Proj4Text,
+	to geoprojbase.Proj4Text,
+	xCoords []float64,
+	yCoords []float64,
+	zCoords []float64,
+) error {
+	if len(xCoords) != len(yCoords) || len(xCoords) != len(zCoords) {
+		return errors.Newf(
+			"len(xCoords) != len(yCoords) != len(zCoords): %d != %d != %d",
+			len(xCoords),
+			len(yCoords),
+			len(zCoords),
+		)
+	}
+	if len(xCoords) == 0 {
+		return nil
+	}
+	if err := cStatusToUnsafeGoBytes(C.CR_PROJ_Transform(
+		(*C.char)(unsafe.Pointer(&from.Bytes()[0])),
+		(*C.char)(unsafe.Pointer(&to.Bytes()[0])),
+		C.long(len(xCoords)),
+		(*C.double)(unsafe.Pointer(&xCoords[0])),
+		(*C.double)(unsafe.Pointer(&yCoords[0])),
+		(*C.double)(unsafe.Pointer(&zCoords[0])),
+	)); err != nil {
+		return errors.Newf("error from PROJ: %s", string(err))
+	}
+	return nil
 }
@@ -13,11 +13,64 @@ package geoproj
 import (
 	"testing"
 
+	"github.com/cockroachdb/cockroach/pkg/geo/geoprojbase"
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
-func TestNewProjPJFromText(t *testing.T) {
-	pjProj, err := NewProjPJFromText("+proj=longlat +datum=WGS84 +no_defs")
-	require.NoError(t, err)
-	require.True(t, pjProj.IsLatLng())
+func TestProject(t *testing.T) {
+	testCases := []struct {
+		desc string
+
+		from    geoprojbase.Proj4Text
+		to      geoprojbase.Proj4Text
+		xCoords []float64
+		yCoords []float64
+		zCoords []float64
+
+		expectedXCoords []float64
+		expectedYCoords []float64
+		// Ignore Z Coord for now; it usually has a garbage value.
+	}{
+		{
+			desc:            "SRID 4326 to 3857",
+			from:            geoprojbase.MakeProj4Text("+proj=longlat +datum=WGS84 +no_defs"),
+			to:              geoprojbase.MakeProj4Text("+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs"),
+			xCoords:         []float64{1},
+			yCoords:         []float64{1},
+			zCoords:         []float64{0},
+			expectedXCoords: []float64{111319.490793274},
+			expectedYCoords: []float64{111325.142866385},
+		},
+		{
+			desc:            "SRID 3857 to 4326",
+			from:            geoprojbase.MakeProj4Text("+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs"),
+			to:              geoprojbase.MakeProj4Text("+proj=longlat +datum=WGS84 +no_defs"),
+			xCoords:         []float64{1},
+			yCoords:         []float64{1},
+			zCoords:         []float64{0},
+			expectedXCoords: []float64{0.000008983152841},
+			expectedYCoords: []float64{0.000008983152841},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.desc, func(t *testing.T) {
+			err := Project(tc.from, tc.to, tc.xCoords, tc.yCoords, tc.zCoords)
+			require.NoError(t, err)
+			assert.InEpsilonSlicef(t, tc.expectedXCoords, tc.xCoords, 1e-10, "expected: %#v, found %#v", tc.expectedXCoords, tc.xCoords)
+			assert.InEpsilonSlicef(t, tc.expectedYCoords, tc.yCoords, 1e-10, "expected: %#v, found %#v", tc.expectedYCoords, tc.yCoords)
+		})
+	}
+
+	t.Run("test error handling", func(t *testing.T) {
+		err := Project(
+			geoprojbase.MakeProj4Text("+bad"),
+			geoprojbase.MakeProj4Text("+bad"),
+			[]float64{1},
+			[]float64{2},
+			[]float64{3},
+		)
+		require.Error(t, err)
+	})
 }
@@ -9,4 +9,62 @@
 // licenses/APL.txt.
 
 #include "proj.h"
+#include <cstring>
 #include <proj_api.h>
+#include <stdlib.h>
+#include <string>
+
+const char* DEFAULT_ERROR_MSG = "PROJ could not parse proj4text";
+
+namespace {
+CR_PROJ_Status CR_PROJ_ErrorFromErrorCode(int code) {
+  char* err = pj_strerrno(code);
+  if (err == nullptr) {
+    err = (char*)DEFAULT_ERROR_MSG;
+  }
+  return {.data = err, .len = strlen(err)};
+}
+
+}  // namespace
+
+CR_PROJ_Status CR_PROJ_Transform(char* fromSpec, char* toSpec, long point_count, double* x,
+                                 double* y, double* z) {
+  CR_PROJ_Status err = {.data = NULL, .len = 0};
+  auto ctx = pj_ctx_alloc();
+  auto fromPJ = pj_init_plus_ctx(ctx, fromSpec);
+  if (fromPJ == nullptr) {
+    err = CR_PROJ_ErrorFromErrorCode(pj_ctx_get_errno(ctx));
+    pj_ctx_free(ctx);
+    return err;
+  }
+  auto toPJ = pj_init_plus_ctx(ctx, toSpec);
+  if (toPJ == nullptr) {
+    err = CR_PROJ_ErrorFromErrorCode(pj_ctx_get_errno(ctx));
+    pj_ctx_free(ctx);
+    return err;
+  }
+  // If we have a latlng from, transform to radians.
+  if (pj_is_latlong(fromPJ)) {
+    for (auto i = 0; i < point_count; i++) {
+      x[i] = x[i] * DEG_TO_RAD;
+      y[i] = y[i] * DEG_TO_RAD;
+    }
+  }
+  pj_transform(fromPJ, toPJ, point_count, 0, x, y, z);
+  int errCode = pj_ctx_get_errno(ctx);
+  if (errCode != 0) {
+    err = CR_PROJ_ErrorFromErrorCode(errCode);
+    pj_ctx_free(ctx);
+    return err;
+  }
+
+  // If we have a latlng to, transform to degrees.
+  if (pj_is_latlong(toPJ)) {
+    for (auto i = 0; i < point_count; i++) {
+      x[i] = x[i] * RAD_TO_DEG;
+      y[i] = y[i] * RAD_TO_DEG;
+    }
+  }
+  pj_ctx_free(ctx);
+  return err;
+}
@@ -7,3 +7,28 @@
 // the Business Source License, use of this software will be governed
 // by the Apache License, Version 2.0, included in the file
 // licenses/APL.txt.
+
+#include <stdlib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// CR_PROJ_Slice contains data that does not need to be freed.
+// // It can be either a Go or C pointer (which indicates who allocated the
+// memory).
+typedef struct {
+  char* data;
+  size_t len;
+} CR_PROJ_Slice;
+
+typedef CR_PROJ_Slice CR_PROJ_Status;
+
+// CR_PROJ_Transform converts the given x/y/z coordinates to a new project specification.
+// Note points (x[i], y[i], z[i]) are in the range 0 <= i < point_coint.
+CR_PROJ_Status CR_PROJ_Transform(char* fromSpec, char* toSpec, long point_count, double* x,
+                                 double* y, double* z);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif