void cdCanvasGetSize(cdCanvas* canvas, int *width, int *height, double *width_mm, double *height_mm); [in C]

canvas:GetSize() -> (width, height, mm_width, mm_height: number) [in Lua]

Returns the canvas size in pixels and in millimeters. You can provide only the desired values and NULL for the others.

int cdCanvasYAxisMode(cdCanvas* canvas, int invert); [in C]

canvas:YAxisMode(invert: number) -> (old_invert: number) [in Lua]

Controls the orientation of the Y axis. Internally in some drivers the native axis orientation is top-bottom, so the CD primitives must invert the Y axis since the CD orientation is bottom-top. Using CD_QUERY will return the current Y axis mode, if needs to be invert or not. Using 1 or 0 you can control if the Y axis should be inverted or not independent from the native orientation, with that you can in fact invert the orientation of the CD primitives.

int cdCanvasUpdateYAxis(cdCanvas* canvas, int *y); [in C]
double cdfCanvasUpdateYAxis(cdCanvas* canvas, double *y); [in C]
int cdCanvasInvertYAxis(cdCanvas* canvas, int y); [in C]
double cdfCanvasInvertYAxis(cdCanvas* canvas, double y); [in C]

canvas:UpdateYAxis(yc: number) -> (yr: number) [in Lua]
canvas:InvertYAxis(yc: number) -> (yr: number) [in Lua]

Converts the coordinate system of the CD library into the internal system of the active canvas' driver, and the other way round, if they are invert, or else do nothing. This is just "y = height-1 - y". It returns the changed value. The "Invert" will always invert the given value, the "Update" function will invert only if the canvas has the Y axis inverted.

void cdCanvasMM2Pixel(cdCanvas* canvas, double mm_dx, double mm_dy, int *dx, int *dy); [in C]
void cdfCanvasMM2Pixel(cdCanvas* canvas, double mm_dx, double mm_dy, double *dx, double *dy); [in C]

canvas:MM2Pixel(mm_dx, mm_dy: number) -> (dx, dy: number) [in Lua]
canvas:fMM2Pixel(mm_dx, mm_dy: number) -> (dx, dy: number) [in Lua]

Converts sizes in millimeters into pixels (canvas coordinates). You can provide only the desired values and NULL for the others.

void cdCanvasPixel2MM(cdCanvas* canvas, int dx, int dy, double *mm_dx, double *mm_dy); [in C]
void cdfCanvasPixel2MM(cdCanvas* canvas, double dx, double dy, double *mm_dx, double *mm_dy); [in C]

canvas:Pixel2MM(dx, dy: number) -> (mm_dx, mm_dy: number) [in Lua]
canvas:fPixel2MM(dx, dy: number) -> (mm_dx, mm_dy: number) [in Lua]

Converts sizes in pixels (canvas coordinates) into millimeters. You can provide only the desired values and NULL for the others. Use this function to obtain the horizontal and vertical resolution of the canvas by passing 1 as parameter in dx and dy. The resolution value is obtained using the formula res=1.0/mm.

void cdCanvasOrigin(cdCanvas* canvas, int x, int y); [in C]
void cdfCanvasOrigin(cdCanvas* canvas, double x, double y); [in C]

canvas:Origin(x, y: number) [in Lua]
canvas:fOrigin(x, y: number) [in Lua]

Allows translating the origin - for instance, to the center of the canvas. The function profits from the architecture of the library to simulate a translation of the origin, which in fact is never actually passed to the canvas in the respective driver. It is not related with WD nor Transformation Matrix. Default values: (0, 0)

void cdCanvasGetOrigin(cdCanvas* canvas, int *x, int *y); [in C]
void cdfCanvasGetOrigin(cdCanvas* canvas, double *x, double *y); [in C]

canvas:GetOrigin() -> (x, y: number) [in Lua]
canvas:fGetOrigin() -> (x, y: number) [in Lua]

Returns the origin.

void cdCanvasTransform(cdCanvas* canvas, const double* matrix); [in C]

canvas:Transform(matrix: table) [in Lua]

Defines a transformation matrix with 6 elements. If the matrix is NULL, the transformation is reset to the identity. Default value: NULL.

The matrix contains scale (sx,sy), rotation (angle) and translation (dx,dy) elements as follows:

|x'|   |sx*cos(angle)    -sin(angle)  dx|   |x|                     |0   2   4| 
|y'| = |   sin(angle)  sy*cos(angle)  dy| * |y|      with indices   |1   3   5|
                                            |1|

In other words:

matrix[0] = sx*cos(angle)           // Horizontal Scale and Rotation component
matrix[1] =    sin(angle)           // Rotation component (can also contain an horizontal shear component)
matrix[2] =   -sin(angle)           // Rotation component (can also contain a vertical shear component)
matrix[3] = sy*cos(angle)           // Vertical Scale and Rotation component
matrix[4] = dx                      // Horizontal Translation component
matrix[5] = dy                      // Vertical Translation component

But notice that the indices are different of the cdCanvasVectorTextTransform.

Functions that retrieve images from the canvas are not affected by the transformation matrix, such as GetImage, GetImageRGB and ScrollArea.

Transformation matrix is independent of the World Coordinate and Origin functions. And those are affected if a transformation is set, just like other regular primitives.

The transformation matrix and world coordinates perform similar functions. World coordinates were developed before the transformation matrix support. The transformation matrix operates at a lower level than world coordinates, and, as such, might be faster, but might behave differently on different platforms. World coordinates behave consistently across platforms.

double* cdCanvasGetTransform(cdCanvas* canvas); [in C]

canvas:GetTransformation() -> (matrix: table) [in Lua]

Returns the transformation matrix. If the identity is set, returns NULL.

void cdCanvasTransforMultiply(cdCanvas* canvas, const double* matrix); [in C]

canvas:TransformMultiply(matrix: table) [in Lua]

Left multiply the current transformation by the given transformation.

void cdCanvasTransformTranslate(cdCanvas* canvas, double dx, double dy); [in C]

canvas:TransformTranslate(dx, dy: number) [in Lua]

Applies a translation to the current transformation.

void cdCanvasTransformScale(cdCanvas* canvas, double sx, double sy); [in C]

canvas:TransformScale(sx, sy: number) [in Lua]

Applies a scale to the current transformation.

void cdCanvasTransformRotate(cdCanvas* canvas, double angle); [in C]

canvas:TransformRotate(angle: number) [in Lua]

Applies a rotation to the current transformation. Angle is in degrees, oriented counter-clockwise from the horizontal axis.

void cdCanvasTransformPoint(cdCanvas* canvas, int x, int y, int *tx, int *ty); [in C]
void cdfCanvasTransformPoint(cdCanvas* canvas, double x, double y, double *tx, double *ty); [in C]

canvas:TransformPoint(x, y: number) -> (tx, ty: number) [in Lua]
canvas:fTransformPoint(x, y: number) -> (tx, ty: number) [in Lua]

Applies a transformation to a given point.