Add freetype

contrib/freetype.cpp

@@ -0,0 +1,31 @@
+#include "freetype.h"
+
+FreeType2 FreeType2_CreateFreeType2() {
+    return new cv::Ptr<cv::freetype::FreeType2>(cv::freetype::createFreeType2());
+}
+
+void FreeType2_Close(FreeType2 f) {
+    delete f;
+}
+
+void FreeType2_LoadFontData(FreeType2 f, const char *fontFileName, int id) {
+    (*f)->loadFontData(fontFileName, id);
+}
+
+void FreeType2_SetSplitNumber(FreeType2 f, int num) {
+    (*f)->setSplitNumber(num);
+}
+
+void FreeType2_PutText(FreeType2 f, Mat img, const char *text, Point org,
+                       int fontHeight, Scalar color,
+                       int thickness, int line_type, bool bottomLeftOrigin) {
+    cv::Point pt(org.x, org.y);
+    cv::Scalar c = cv::Scalar(color.val1, color.val2, color.val3, color.val4);
+    (*f)->putText(*img, text, pt, fontHeight, c, thickness, line_type, bottomLeftOrigin);
+}
+
+Size FreeType2_GetTextSize(FreeType2 f, const char *text,
+                           int fontHeight, int thickness, int *baseLine) {
+    cv::Size sz = (*f)->getTextSize(text, fontHeight, thickness, baseLine);
+    return Size{sz.width, sz.height};
+}

contrib/freetype.go

@@ -0,0 +1,103 @@
+package contrib
+
+/*
+#include <stdlib.h>
+#include "freetype.h"
+*/
+import "C"
+import (
+	"image"
+	"image/color"
+	"unsafe"
+
+	"gocv.io/x/gocv"
+)
+
+type FreeType2 struct {
+	// C.FreeType2
+	p unsafe.Pointer
+}
+
+// NewFreeType2 create instance to draw UTF-8 strings.
+//
+// For further details, please see:
+// https://docs.opencv.org/master/d4/dfc/group__freetype.html#ga0fd8f9c0ae69bb4d95c41af79473a756
+//
+func NewFreeType2() FreeType2 {
+	return FreeType2{p: unsafe.Pointer(C.FreeType2_CreateFreeType2())}
+}
+
+// Close FreeType2.
+func (f *FreeType2) Close() error {
+	C.FreeType2_Close((C.FreeType2)(f.p))
+	f.p = nil
+	return nil
+}
+
+// LoadFontData loads font data.
+//
+// For further details, please see:
+// https://docs.opencv.org/master/d9/dfa/classcv_1_1freetype_1_1FreeType2.html#af059d49b806b916ffdd6380b9eb2f59a
+//
+func (f *FreeType2) LoadFontData(fontFileName string, id int) {
+	cFontFileName := C.CString(fontFileName)
+	defer C.free(unsafe.Pointer(cFontFileName))
+	C.FreeType2_LoadFontData((C.FreeType2)(f.p), cFontFileName, C.int(id))
+}
+
+// SetSplitNumber set the number of split points from bezier-curve to line.
+// If you want to draw large glyph, large is better.
+// If you want to draw small glyph, small is better.
+//
+// For further details, please see:
+// https://docs.opencv.org/master/d9/dfa/classcv_1_1freetype_1_1FreeType2.html#a572143e6c68eab181387d9f4b3366f8b
+//
+func (f *FreeType2) SetSplitNumber(num int) {
+	C.FreeType2_SetSplitNumber((C.FreeType2)(f.p), C.int(num))
+}
+
+// PutText draws a text string.
+// It renders the specified text string in the image.
+// Symbols that cannot be rendered using the specified font are replaced by "Tofu" or non-drawn.
+//
+// For further details, please see:
+// https://docs.opencv.org/master/d9/dfa/classcv_1_1freetype_1_1FreeType2.html#aba641f774c47a70eaeb76bf7aa865915
+//
+func (f *FreeType2) PutText(img *gocv.Mat, text string, org image.Point,
+	fontHeight int, c color.RGBA, thickness int, lineType gocv.LineType, bottomLeftOrigin bool) {
+	cText := C.CString(text)
+	defer C.free(unsafe.Pointer(cText))
+
+	sOrg := C.struct_Point{
+		x: C.int(org.X),
+		y: C.int(org.Y),
+	}
+
+	sColor := C.struct_Scalar{
+		val1: C.double(c.B),
+		val2: C.double(c.G),
+		val3: C.double(c.R),
+		val4: C.double(c.A),
+	}
+
+	C.FreeType2_PutText((C.FreeType2)(f.p), (C.Mat)(img.Ptr()), cText, sOrg, C.int(fontHeight), sColor, C.int(thickness), C.int(lineType), C.bool(bottomLeftOrigin))
+}
+
+// GetTextSize calculates the width and height of a text string.
+// The function getTextSize calculates and returns the approximate size of a box that contains the specified text.
+// That is, the following code renders some text, the tight box surrounding it, and the baseline.
+//
+// For further details, please see:
+// https://docs.opencv.org/master/d9/dfa/classcv_1_1freetype_1_1FreeType2.html#af135a132505125bdea74b378dda3bb5d
+//
+func (f *FreeType2) GetTextSize(text string, fontHeight int, thickness int) (image.Point, int) {
+	cText := C.CString(text)
+	defer C.free(unsafe.Pointer(cText))
+	cBaseLine := C.int(0)
+
+	sz := C.FreeType2_GetTextSize((C.FreeType2)(f.p), cText, C.int(fontHeight), C.int(thickness), &cBaseLine)
+	return image.Point{
+		X: int(sz.width),
+		Y: int(sz.height),
+	}, int(cBaseLine)
+}

contrib/freetype.h

@@ -0,0 +1,33 @@
+#ifndef _OPENCV3_FREETYPE2_H_
+#define _OPENCV3_FREETYPE2_H_
+
+#ifdef __cplusplus
+#include <opencv2/opencv.hpp>
+#include <opencv2/freetype.hpp>
+extern "C" {
+#endif
+
+#include "../core.h"
+
+#ifdef __cplusplus
+typedef cv::Ptr<cv::freetype::FreeType2>* FreeType2;
+#else
+typedef void* FreeType2;
+#endif
+
+FreeType2 FreeType2_CreateFreeType2();
+void FreeType2_Close(FreeType2 f);
+void FreeType2_LoadFontData(FreeType2 f, const char* fontFileName, int id);
+void FreeType2_SetSplitNumber(FreeType2 f, int num);
+void FreeType2_PutText(FreeType2 f, Mat img, const char* text, Point org,
+        int fontHeight, Scalar color,
+        int thickness, int line_type, bool bottomLeftOrigin
+    );
+Size FreeType2_GetTextSize(FreeType2 f, const char* text,
+                                int fontHeight, int thickness, int* baseLine);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif //_OPENCV3_FREETYPE2_H_

contrib/freetype_test.go

@@ -0,0 +1,65 @@
+package contrib
+
+import (
+	"image"
+	"image/color"
+	"testing"
+
+	"gocv.io/x/gocv"
+)
+
+func TestFreeTypeLoadFontData(t *testing.T) {
+	ft := NewFreeType2()
+	defer ft.Close()
+
+	ft.LoadFontData("../fonts/JetBrainsMono-Regular.ttf", 0)
+}
+
+func TestFreeTypeGetTextSize(t *testing.T) {
+	ft := NewFreeType2()
+	defer ft.Close()
+
+	ft.LoadFontData("../fonts/JetBrainsMono-Regular.ttf", 0)
+
+	size, baseLine := ft.GetTextSize("test", 60, 2)
+
+	if size.X != 140 {
+		t.Error("Invalid text size width")
+	}
+
+	if size.Y != 46 {
+		t.Error("Invalid text size height")
+	}
+
+	if baseLine != 1 {
+		t.Errorf("invalid base. expected %d, actual %d", 1, baseLine)
+	}
+}
+
+func TestFreeTypePutText(t *testing.T) {
+	ft := NewFreeType2()
+	defer ft.Close()
+
+	ft.LoadFontData("../fonts/JetBrainsMono-Regular.ttf", 0)
+
+	img := gocv.NewMatWithSize(150, 500, gocv.MatTypeCV8UC3)
+	if img.Empty() {
+		t.Error("Invalid Mat")
+	}
+	defer img.Close()
+
+	pt := image.Pt(80, 80)
+	ft.PutText(&img, "Testing", pt, 60, color.RGBA{R: 255, G: 255, B: 255}, 2, 8, true)
+
+	if img.Empty() {
+		t.Error("Error in PutText test")
+	}
+}
+
+func TestFreeTypeSetSplitNumber(t *testing.T) {
+	ft := NewFreeType2()
+	defer ft.Close()
+
+	ft.LoadFontData("../fonts/JetBrainsMono-Regular.ttf", 0)
+	ft.SetSplitNumber(10)
+}