The following example draws the original source image and then draws a portion of the image in a specified parallelogram.
C++
VOID Example_DrawImage4(HDC hdc)
{
Graphics graphics(hdc);
// Create an Image object.
Image image(L"pattern.png");
// Draw the original source image.
graphics.DrawImage(&image, 10, 10);
// Define the portion of the image to draw.
REAL srcX = 70.0f;
REAL srcY = 20.0f;
REAL srcWidth = 100.0f;
REAL srcHeight = 100.0f;
// Create an array of Point objects that specify the destination of the cropped image.
PointF destPoints[3] = {
PointF(230.0f, 30.0f),
PointF(350.0f, 50.0f),
PointF(275.0f, 120.0f)};
Point* pdestPoints = destPoints;
// Create an ImageAttributes object that specifies a recoloring from red to blue.
ImageAttributes remapAttributes;
ColorMap redToBlue;
redToBlue.oldColor = Color(255, 255, 0, 0);
redToBlue.newColor = Color(255, 0, 0, 255);
remapAttributes.SetRemapTable(1, &redToBlue);
// Draw the cropped image.
graphics.DrawImage(
&image,
pdestPoints,
3,
srcX,
srcY,
srcWidth,
srcHeight,
UnitPixel,
&remapAttributes,
NULL,
NULL);
}
SUB GDIP_GdipDrawImagePointsRect (BYVAL hdc AS DWORD)
LOCAL hStatus AS LONG
LOCAL pGraphics AS DWORD
LOCAL pImage AS DWORD
LOCAL strFileName AS STRING
LOCAL srcx AS SINGLE
LOCAL srcy AS SINGLE
LOCAL srcwidth AS SINGLE
LOCAL srcheight AS SINGLE
LOCAL pRemapAttributes AS DWORD
LOCAL redToBlue AS GDIP_COLORMAP
DIM destPoints(2) AS POINTF
hStatus = GdipCreateFromHDC(hdc, pGraphics)
' // Create the Image object
strFileName = UCODE$("pattern.png")
hStatus = GdipLoadImageFromFile(STRPTR(strFileName), pImage)
' // Draw the original source image.
hStatus = GdipDrawImage(pGraphics, pImage, 10, 10)
' // Define the portion of the image to draw.
srcX = 70.0!
srcY = 20.0!
srcwidth = 100.0!
srcheight = 100.0!
' // Create an array of Point structures that specify the destination of the cropped image.
destPoints(0).x = 230.0! : destPoints(0).y = 30.0!
destPoints(1).x = 350.0! : destPoints(1).y = 50.0!
destPoints(2).x = 275.0! : destPoints(2).y = 120.0!
' // Create an ImageAttributes object that specifies a recoloring from red to blue.
hStatus = GdipCreateImageAttributes(pRemapAttributes)
redToBlue.oldColor = GDIP_ARGB(255, 255, 0, 0)
redToBlue.newColor = GDIP_ARGB(255, 0, 0, 255)
hStatus = GdipSetImageAttributesRemapTable(pRemapAttributes, %ColorAdjustTypeDefault, %TRUE, 1, redToBlue)
' Draw the cropped image
hStatus = GdipDrawImagePointsRect(pGraphics, pImage, destPoints(0), 3, srcx, srcy, _
srcwidth, srcheight, %UnitPixel, pRemapAttributes, %NULL, %NULL)
' // Cleanup
IF pRemapAttributes THEN GdipDisposeImageAttributes(pRemapAttributes)
IF pImage THEN GdipDisposeImage(pImage)
IF pGraphics THEN GdipDeleteGraphics(pGraphics)
END SUB
(http://www.jose.it-berater.org/captures/GdipDrawImagePointsRect.png)