Expose ConvertImageCommand function in imagick.v2 (refs #220)

examples/convert_command/main.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+	"fmt"
+
+	"gopkg.in/gographics/imagick.v3/imagick"
+)
+
+func main() {
+	imagick.Initialize()
+	defer imagick.Terminate()
+
+	ret, err := imagick.ConvertImageCommand([]string{
+		"convert", "logo:", "-resize", "100x100", "/tmp/out.png",
+	})
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Printf("Metadata:\n%s\n", ret.Meta)
+}

examples/docker/go.mod

@@ -2,3 +2,4 @@ module resizer
 
 require gopkg.in/gographics/imagick.v2 v2.5.0
 
+go 1.13

examples/docker/go.sum

@@ -0,0 +1 @@
+gopkg.in/gographics/imagick.v2 v2.5.0/go.mod h1:of4TbGX8yMcpgWkWFjha7FsOFr+NjOJ5O1qtKU27Yj0=

imagick/exception_info.go

@@ -0,0 +1,78 @@
+// Copyright 2013 Herbert G. Fischer. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package imagick
+
+/*
+#include <wand/MagickWand.h>
+*/
+import "C"
+
+import "fmt"
+
+// ExceptionInfo is an error type returned by certain
+// New* API calls.
+type ExceptionInfo struct {
+	kind        ExceptionType
+	errno       int
+	reason      string
+	description string
+}
+
+// Create a new ExceptionInfo wrapper around a C ExceptionInfo ptr
+func newExceptionInfo(errInfo *C.ExceptionInfo) *ExceptionInfo {
+	if errInfo == nil {
+		return nil
+	}
+
+	return &ExceptionInfo{
+		kind:        ExceptionType(errInfo.severity),
+		errno:       int(errInfo.error_number),
+		reason:      C.GoString(errInfo.reason),
+		description: C.GoString(errInfo.description),
+	}
+}
+
+// Check if a given C ExceptionInfo ptr is an error.
+// Returns a valid ExceptionInfo if there was an error,
+// otherwise returns nil
+func checkExceptionInfo(errInfo *C.ExceptionInfo) *ExceptionInfo {
+	if errInfo != nil && errInfo.error_number != 0 {
+		return newExceptionInfo(errInfo)
+	}
+
+	return nil
+}
+
+func (e *ExceptionInfo) Error() string {
+	if e == nil {
+		return ""
+	}
+	return fmt.Sprintf("%s (%d): %s %s",
+		e.kind.String(), e.Errno(), e.Reason(), e.Description())
+}
+
+// Errno returns the ExceptionInfo error number (non-zero if error)
+func (e *ExceptionInfo) Errno() int {
+	if e == nil {
+		return 0
+	}
+	return e.errno
+}
+
+// Reason returns the string reason for the Exception
+func (e *ExceptionInfo) Reason() string {
+	if e == nil {
+		return ""
+	}
+	return e.reason
+}
+
+// Description returns the string description for the Exception
+func (e *ExceptionInfo) Description() string {
+	if e == nil {
+		return ""
+	}
+	return e.description
+}

imagick/image.go

@@ -6,9 +6,13 @@ package imagick
 
 /*
 #include <magick/MagickCore.h>
+#include <wand/MagickWand.h>
 */
 import "C"
-import "runtime"
+import (
+	"runtime"
+	"unsafe"
+)
 
 type Image struct {
 	img *C.Image
@@ -20,3 +24,61 @@ func NewMagickImage(info *ImageInfo, width, height uint, background *MagickPixel
 	runtime.KeepAlive(background)
 	return ret
 }
+
+// ImageCommandResult is returned by a call to
+// ConvertImageCommand. It contains the ImageInfo
+// and Metadata string generated by the convert command.
+type ImageCommandResult struct {
+	Info *ImageInfo
+	Meta string
+}
+
+/*
+ConvertImageCommand reads one or more images, applies one or more image
+processing operations, and writes out the image in the same or differing
+format.
+The first item in the args list is expected to be the program name, ie "convert".
+*/
+func ConvertImageCommand(args []string) (*ImageCommandResult, error) {
+	size := len(args)
+
+	cmdArr := make([]*C.char, size)
+	for i, s := range args {
+		cmdArr[i] = C.CString(s)
+	}
+
+	empty := C.CString("")
+	metaStr := C.AcquireString(empty)
+	C.free(unsafe.Pointer(empty))
+
+	defer func() {
+		for i := range cmdArr {
+			C.free(unsafe.Pointer(cmdArr[i]))
+		}
+
+		C.DestroyString(metaStr)
+	}()
+
+	imageInfo := newImageInfo()
+
+	var exc *C.ExceptionInfo = C.AcquireExceptionInfo()
+	defer C.DestroyExceptionInfo(exc)
+
+	ok := C.ConvertImageCommand(
+		imageInfo.info,
+		C.int(size), // argc
+		&cmdArr[0],  // argv
+		&metaStr,    // metadata
+		exc,         // exception
+	)
+	if C.int(ok) == 0 {
+		imageInfo.Destroy()
+		return nil, newExceptionInfo(exc)
+	}
+
+	ret := &ImageCommandResult{
+		Info: imageInfo,
+		Meta: C.GoString(metaStr),
+	}
+	return ret, nil
+}

imagick/image_info.go

@@ -8,7 +8,25 @@ package imagick
 #include <magick/MagickCore.h>
 */
 import "C"
+import "runtime"
 
 type ImageInfo struct {
 	info *C.ImageInfo
 }
+
+func newImageInfo() *ImageInfo {
+	ptr := C.AcquireImageInfo()
+	C.GetImageInfo(ptr)
+	imageInfo := &ImageInfo{ptr}
+	runtime.SetFinalizer(imageInfo, Destroy)
+	return imageInfo
+}
+
+// Destroy the ImageInfo immediately.
+// This will also be called automatically during garbage collection.
+func (ii *ImageInfo) Destroy() {
+	if ii.info != nil {
+		C.DestroyImageInfo(ii.info)
+		ii.info = nil
+	}
+}

imagick/image_test.go

@@ -0,0 +1,62 @@
+// Copyright 2013 Herbert G. Fischer. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package imagick
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"testing"
+)
+
+func init() {
+	Initialize()
+}
+
+// TODO(justinfx): Need to expand test to try and
+// produce and catch an error from NewPixelWand
+func TestNewMagickImage(t *testing.T) {
+	info := newImageInfo()
+	defer info.Destroy()
+
+	pp, err := QueryMagickColor("blue")
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+
+	img := NewMagickImage(info, 100, 100, pp)
+	if img == nil {
+		t.Fatal("nil MagickImage")
+	}
+}
+
+func ExampleConvertImageCommand() {
+	ret, err := ConvertImageCommand([]string{
+		"convert", "logo:", "-resize", "100x100", "/tmp/out.png",
+	})
+	if err != nil {
+		panic(err)
+	}
+	fmt.Println("Meta:", ret.Meta)
+}
+
+func TestConvertImageCommand(t *testing.T) {
+	tmp, err := ioutil.TempFile("", "imagick_test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.Remove(tmp.Name())
+
+	ret, err := ConvertImageCommand([]string{
+		"convert", "logo:", "-resize", "100x100", tmp.Name(),
+	})
+	if err != nil {
+		t.Fatalf("command failed: %v", err)
+	}
+
+	if ret.Meta == "" {
+		t.Fatal("got empty metadata string from command result")
+	}
+}

imagick/magick_pixel_packet.go

@@ -8,11 +8,77 @@ package imagick
 #include <magick/MagickCore.h>
 */
 import "C"
+import "unsafe"
 
+// MagickPixelPacket is constructed using NewMagickPixelPacket
 type MagickPixelPacket struct {
 	mpp *C.MagickPixelPacket
 }
 
+func (p *MagickPixelPacket) Red() float64 {
+	return float64(p.mpp.red)
+}
+
+func (p *MagickPixelPacket) SetRed(value float64) {
+	p.mpp.red = C.MagickRealType(value)
+}
+
+func (p *MagickPixelPacket) Green() float64 {
+	return float64(p.mpp.green)
+}
+
+func (p *MagickPixelPacket) SetGreen(value float64) {
+	p.mpp.green = C.MagickRealType(value)
+}
+
+func (p *MagickPixelPacket) Blue() float64 {
+	return float64(p.mpp.blue)
+}
+
+func (p *MagickPixelPacket) SetBlue(value float64) {
+	p.mpp.blue = C.MagickRealType(value)
+}
+
+func (p *MagickPixelPacket) Opacity() float64 {
+	return float64(p.mpp.opacity)
+}
+
+func (p *MagickPixelPacket) SetOpacity(value float64) {
+	p.mpp.opacity = C.MagickRealType(value)
+}
+
+func (p *MagickPixelPacket) Index() float64 {
+	return float64(p.mpp.index)
+}
+
+func (p *MagickPixelPacket) SetIndex(value float64) {
+	p.mpp.index = C.MagickRealType(value)
+}
+
+func NewMagickPixelPacket() *MagickPixelPacket {
+	var mpp C.MagickPixelPacket
+	return &MagickPixelPacket{mpp: &mpp}
+}
+
 func newMagickPixelPacketFromCAPI(mpp *C.MagickPixelPacket) *MagickPixelPacket {
 	return &MagickPixelPacket{mpp}
 }
+
+// QueryMagickColor returns the red, green, blue, and opacity
+// intensities for a given color name.
+func QueryMagickColor(colorName string) (*MagickPixelPacket, error) {
+	cstr := C.CString(colorName)
+	defer C.free(unsafe.Pointer(cstr))
+
+	var mpp C.MagickPixelPacket
+
+	var exc *C.ExceptionInfo = C.AcquireExceptionInfo()
+	defer C.DestroyExceptionInfo(exc)
+
+	ok := C.QueryMagickColor(cstr, &mpp, exc)
+	if C.int(ok) == 0 {
+		return nil, newExceptionInfo(exc)
+	}
+
+	return newMagickPixelPacketFromCAPI(&mpp), nil
+}