Bitmap/Bézier curves/Cubic: Difference between revisions
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=={{header|Ada}}== |
=={{header|Ada}}== |
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<lang ada> |
<lang ada>procedure Cubic_Bezier |
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procedure Cubic_Bezier |
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( Picture : in out Image; |
( Picture : in out Image; |
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P1, P2, P3, P4 : Point; |
P1, P2, P3, P4 : Point; |
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Line (Picture, Points (I), Points (I + 1), Color); |
Line (Picture, Points (I), Points (I + 1), Color); |
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end loop; |
end loop; |
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end Cubic_Bezier; |
end Cubic_Bezier;</lang> |
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</lang> |
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The following test |
The following test |
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<lang ada> |
<lang ada> X : Image (1..16, 1..16); |
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X : Image (1..16, 1..16); |
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begin |
begin |
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Fill (X, White); |
Fill (X, White); |
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Cubic_Bezier (X, (16, 1), (1, 4), (3, 16), (15, 11), Black); |
Cubic_Bezier (X, (16, 1), (1, 4), (3, 16), (15, 11), Black); |
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Print (X); |
Print (X);</lang> |
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</lang> |
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should produce output: |
should produce output: |
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<pre> |
<pre> |
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{{works with|ALGOL 68G|Any - tested with release mk15-0.8b.fc9.i386}} |
{{works with|ALGOL 68G|Any - tested with release mk15-0.8b.fc9.i386}} |
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<!-- {{does not work with|ELLA ALGOL 68|Any (with appropriate job cards) - tested with release 1.8.8d.fc9.i386 - '''pragmat''' '''read''' is not part of algol68rs}} --> |
<!-- {{does not work with|ELLA ALGOL 68|Any (with appropriate job cards) - tested with release 1.8.8d.fc9.i386 - '''pragmat''' '''read''' is not part of algol68rs}} --> |
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<lang |
<lang algol68>PRAGMAT READ "Bresenhams_line_algorithm.a68" PRAGMAT; |
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cubic bezier OF class image := |
cubic bezier OF class image := |
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This subroutine should go inside the <code>RCImagePrimitive</code> module (see [[Bresenham's line algorithm]]) |
This subroutine should go inside the <code>RCImagePrimitive</code> module (see [[Bresenham's line algorithm]]) |
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<lang fortran> |
<lang fortran>subroutine cubic_bezier(img, p1, p2, p3, p4, color) |
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type(rgbimage), intent(inout) :: img |
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type(point), intent(in) :: p1, p2, p3, p4 |
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type(rgb), intent(in) :: color |
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integer :: i, j |
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real :: pts(0:N_SEG,0:1), t, a, b, c, d, x, y |
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do i = 0, N_SEG |
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t = real(i) / real(N_SEG) |
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a = (1.0 - t)**3.0 |
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b = 3.0 * t * (1.0 - t)**2.0 |
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c = 3.0 * (1.0 - t) * t**2.0 |
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d = t**3.0 |
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x = a * p1%x + b * p2%x + c * p3%x + d * p4%x |
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y = a * p1%y + b * p2%y + c * p3%y + d * p4%y |
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pts(i,0) = x |
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pts(i,1) = y |
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end do |
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do i = 0, N_SEG-1 |
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j = i + 1 |
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call draw_line(img, point(pts(i,0), pts(i,1)), & |
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point(pts(j,0), pts(j,1)), color) |
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end do |
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end subroutine cubic_bezier</lang> |
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=={{header|J}}== |
=={{header|J}}== |
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'''Example usage:''' |
'''Example usage:''' |
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<lang j> |
<lang j>myimg=: 0 0 255 makeRGB 300 300 |
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]randomctrlpts=: ,3 2 ?@$ }:$ myimg NB. 3 control points - quadratic |
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]randomctrlpts=: ,4 2 ?@$ }:$ myimg NB. 4 control points - cubic |
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myimg=: ((2 ,.~ _2]\randomctrlpts);255 0 255) drawCircles myimg NB. draw control points |
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viewRGB (randomctrlpts; 255 255 0) drawBezier myimg NB. display image with bezier line</lang> |
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=={{header|OCaml}}== |
=={{header|OCaml}}== |
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=={{header|R}}== |
=={{header|R}}== |
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| ⚫ | |||
<lang R> |
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| ⚫ | |||
# n: the number of points in the curve. |
# n: the number of points in the curve. |
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bezierCurve <- function(x, y, n=10) |
bezierCurve <- function(x, y, n=10) |
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y <- 1:6 |
y <- 1:6 |
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plot(x, y, "o", pch=20) |
plot(x, y, "o", pch=20) |
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points(bezierCurve(x,y,20), type="l", col="red") |
points(bezierCurve(x,y,20), type="l", col="red")</lang> |
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</lang> |
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=={{header|Ruby}}== |
=={{header|Ruby}}== |
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{{TI-image-task}} |
{{TI-image-task}} |
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< |
<lang ti89b>Define cubic(p1,p2,p3,p4,segs) = Prgm |
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Local i,t,u,prev,pt |
Local i,t,u,prev,pt |
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0 → pt |
0 → pt |
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EndIf |
EndIf |
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EndFor |
EndFor |
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EndPrgm</ |
EndPrgm</lang> |
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