_TITLE "Another RotoZoom Demo" 'b+ started 2020-03-02
CONST xmax
= 1200, ymax
= 700, xc
= 600, yc
= 350 DIM a
, x
, y
, x1
, y1
, xs
, dxs
, ddxs
, ys
, dys
, ddys
, maxScale
' Starting from an image I pulled from Internet, I used Paint 3D to give it a transparent background.
s&
= _LOADIMAGE("tspike.png") 't for transparent background
' Standard Rotation about the image center on a given X, Y location. Rotating image in middle of screen,
' I used something like this to find ideal angle for level point on left head on right.
RotoZoom3 xc, yc, s&, 1, 1, a
PRINT "radian angle:"; a;
" degrees:";
_R2D(a
) \
1;
" press key for next angle... esc to rotate on y axis"
ao
= _PI(.27) ' I have to offset the image angle by this amount so that the spike point is on the left' and the head is on the right at 0 degrees or radians.
'Demo of the independent x and y scale for axis rotations
maxScale = 4: dxs = .01: ddxs = 1: xs = maxScale:
PRINT "Press any for rotation on x axis..." RotoZoom3 xc, yc, s&, xs, maxScale, ao
IF xs
+ dxs
> maxScale
OR xs
+ dxs
< -maxScale
THEN ddxs
= ddxs
* -1 xs = xs + dxs * ddxs
ys = maxScale: dys = .01: ddys = 1
PRINT "Press any to see layout of image over whole screen and end demo..." RotoZoom3 xc, yc, s&, maxScale, ys, ao
IF ys
+ dys
> maxScale
OR ys
+ dys
< -maxScale
THEN ddys
= ddys
* -1 ys = ys + dys * ddys
' Demo of an applied layout on screen
COLOR , &HFFBBBBBB:
CLS ' the image has slight gray halo so hide with gray background RotoZoom3 x
, 15, s&
, .2, .2, _PI(1.5 + .27) RotoZoom3 x
, _HEIGHT - 15, s&
, .2, .2, _PI(.5 + .27) RotoZoom3
15, y
, s&
, .2, .2, _PI(1 + .27) RotoZoom3
_WIDTH - 15, y
, s&
, .2, .2, _PI(.27) RotoZoom3 x1, y1, s&, 2, 2, a + ao
'And finally a little show. What is better than a knife thrower throwing bananas?
drawKite xc, .9 * ymax, 600, a + ao
SUB drawKite
(x
, y
, s
, a
) drawKite x
+ .5 * s
* COS(_PI(2) - a
), (y
- .25 * s
) + .25 * s
* SIN(_PI(2) - a
), s
/ 1.5, a
drawKite x
+ .5 * s
* COS(_PI + a
), (y
- .25 * s
) + .25 * s
* SIN(_PI + a
), s
/ 1.5, a
' Description:
' Started from a mod of Galleon's in Wiki that both scales and rotates an image.
' This version scales the x-axis and y-axis independently allowing rotations of image just by changing X or Y Scales
' making this tightly coded routine a very powerful and versatile image tool.
' This assumes you have set your drawing location with _DEST or default to screen.
' X, Y - is where you want to put the middle of the image
' Image - is the handle assigned with _LOADIMAGE
' xScale, yScale - are shrinkage < 1 or magnification > 1 on the given axis, 1 just uses image size.
' These are multipliers so .5 will create image .5 size on given axis and 2 for twice image size.
' radianRotation is the Angle in Radian units to rotate the image
' note: Radian units for rotation because it matches angle units of other Basic Trig functions
' and saves a little time converting from degree.
' Use the _D2R() function if you prefer to work in degree units for angles.
DIM W&
, H&
, sinr!
, cosr!
, i&
, x2&
, y2&
' variables for image manipulation px(0) = -W& / 2: py(0) = -H& / 2 'left top corner
px(1) = -W& / 2: py(1) = H& / 2 ' left bottom corner
px(2) = W& / 2: py(2) = H& / 2 ' right bottom
px(3) = W& / 2: py(3) = -H& / 2 ' right top
sinr!
= SIN(-radianRotation
): cosr!
= COS(-radianRotation
) ' rotation helpers FOR i&
= 0 TO 3 ' calc new point locations with rotation and zoom x2& = xScale * (px(i&) * cosr! + sinr! * py(i&)) + X: y2& = yScale * (py(i&) * cosr! - px(i&) * sinr!) + Y
px(i&) = x2&: py(i&) = y2&
