How to draw curved text using MFC functions? - winapi

Question

How to draw curved text using MFC functions? I want to achieve like this below.
DrawText() function draws text in straight line only, I do not know how to draw curved text at particular angle. Please help me.
Thanks.

Answer 1

You could use GDI+, There is a sample in code project, which is written in C#, I translate it into C++:
Graphics graphics(hWnd);
RECT rect = { 0 };
GetWindowRect(hWnd, &rect);
POINT center = { (rect.right - rect.left) / 2,(rect.bottom - rect.top) / 2 };
double radius = min(rect.right - rect.left, (rect.bottom - rect.top)) / 3;
TCHAR text[] = L"ABCDEFGHIJLKMNOPQRSTUVWXYZ";
REAL emSize = 24;
Font* font = new Font(FontFamily::GenericSansSerif(), emSize, FontStyleBold);
for (int i = 0; i < _tcslen(text); ++i)
{
RectF re, in;
Status result = graphics.MeasureString(&text[i], 1, font, in, &re);;
double charRadius = radius + re.Height;
double angle = (((float)i / _tcslen(text)) - 0.25) * 2 * M_PI;
double x = (int)(center.x + cos(angle) * charRadius);
double y = (int)(center.y + sin(angle) * charRadius);
result = graphics.TranslateTransform(x, y);
result = graphics.RotateTransform((float)(90 + 360 * angle / (2 * M_PI)));
PointF start(0, 0);
SolidBrush Red(Color(255, 255, 0, 0));
result = graphics.DrawString(&text[i], 1, font, start, &Red);
result = graphics.ResetTransform();
SolidBrush Green(Color(255, 0, 255, 0));
Pen* pen = new Pen(&Green, 2.0f);
result = graphics.DrawArc(pen, (REAL)(center.x - radius), (REAL)(center.y - radius), radius * 2, radius * 2, 0, 360);
}
Some header files:
#define _USE_MATH_DEFINES
#include <math.h>
#include <windows.h>
#include <objidl.h>
#include <gdiplus.h>
using namespace Gdiplus;
#pragma comment (lib,"Gdiplus.lib")
Usage:
You must call GdiplusStartup before you create any GDI+ objects, and
you must delete all of your GDI+ objects (or have them go out of
scope) before you call GdiplusShutdown.
GdiplusStartupInput gdiplusStartupInput;
ULONG_PTR gdiplusToken;
GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);
//To Do.
GdiplusShutdown(gdiplusToken);
Result:
UPDATE:
Graphics graphics(hWnd);
RECT rect = { 0 };
GetWindowRect(hWnd, &rect);
POINT center = { (rect.right - rect.left) / 2,(rect.bottom - rect.top) / 2 };
double radius = min(rect.right - rect.left, (rect.bottom - rect.top)) / 3;
TCHAR text[72][4] = { 0 };
for (int i = 0; i < 72; i++)
{
_itot((i/2)*10, text[i],10);
i++;
_tcscpy(text[i],L"");
}
REAL emSize = 8;
Font* font = new Font(FontFamily::GenericSansSerif(), emSize, FontStyleBold);
for (int i = 0; i < 72; ++i)
{
RectF re, in,rel;
Status result = graphics.MeasureString(text[i], _tcslen(text[i]), font, in, &re);
result = graphics.MeasureString(L"|", 1, font, in, &rel);
double charRadius = radius - re.Height;
double angle = (((float)i / 72) - 0.25) * 2 * M_PI;
double x = (center.x + cos(angle) * charRadius);
double y = (center.y + sin(angle) * charRadius);
result = graphics.TranslateTransform(x, y);
result = graphics.RotateTransform((float)(90 + 360 * angle / (2 * M_PI)));
PointF start(0- re.Width/2, 0);
SolidBrush Red(Color(255, 255, 0, 0));
result = graphics.DrawString(text[i], _tcslen(text[i]), font, start, &Red);
result = graphics.ResetTransform();
x = (int)(center.x + cos(angle) * radius);
y = (int)(center.y + sin(angle) * radius);
result = graphics.TranslateTransform(x, y);
result = graphics.RotateTransform((float)(90 + 360 * angle / (2 * M_PI)));
PointF start1(0 - rel.Width / 2, 0);
result = graphics.DrawString(L"|", 1, font, start1, &Red);
result = graphics.ResetTransform();
}
SolidBrush Green(Color(255, 0, 255, 0));
Pen* pen = new Pen(&Green, 2.0f);
Status result = graphics.DrawArc(pen, (REAL)(center.x - radius), (REAL)(center.y - radius), radius * 2, radius * 2, 0, 360);
Result: