mirror of
https://git.sr.ht/~rabbits/macintosh_cookbook
synced 2024-06-04 16:29:31 +00:00
113 lines
2.0 KiB
ObjectPascal
113 lines
2.0 KiB
ObjectPascal
program ExampleBezier;
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type
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mat = array[1..4, 1..4] of Real;
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var
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Px, Py, Cx, Cy: mat;
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Tv, Mb, x, y: mat;
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i, j, k, xx, yy: Integer;
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window: rect;
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t, dt: Real;
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P: point;
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procedure matmlt (var d, a, b: mat; n, m: integer);
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var
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i, j, k: Integer;
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sum: Real;
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temp: mat;
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begin
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for i := 1 to n do
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begin
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for j := 1 to m do
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begin
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sum := 0.0;
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for k := 1 to 4 do
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sum := sum + a[i, k] * b[k, j];
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temp[i, j] := sum;
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end;
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end;
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for i := 1 to n do
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for j := 1 to m do
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d[i, j] := temp[i, j];
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end;
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procedure getPoints;
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var
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i, x, y: Integer;
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begin
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SetRect(window, 30, 30, 400, 300);
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setDrawingRect(window);
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ShowDrawing;
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penSize(2, 2);
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Moveto(40, 20); {Print heading }
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textSize(18);
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textFont(2);
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writeDraw('Bezier Parametric Cubic Curve');
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textSize(12);
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ForeColor(409); {Set pen to blue.}
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for i := 1 to 4 do
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begin
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SetRect(window, 90, 30, 255, 50);
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eraseRect(window);
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Moveto(100, 45);
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writeDraw('Please click in point', I : 3);
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FrameRect(window);
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repeat
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getMouse(P)
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until button;
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repeat
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until (not button);
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Px[i, 1] := P.h;
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Py[i, 1] := P.v;
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SetRect(window, (P.h - 2), (P.v - 2), (P.h + 4), (P.v + 4));
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PaintOval(window);
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end;
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end;
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procedure set_BezMat;
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begin
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Mb[1, 1] := -1;
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Mb[1, 2] := 3;
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Mb[1, 3] := -3;
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Mb[1, 4] := 1;
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Mb[2, 1] := 3;
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Mb[2, 2] := -6;
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Mb[2, 3] := 3;
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Mb[2, 4] := 0;
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Mb[3, 1] := -3;
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Mb[3, 2] := 3;
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Mb[3, 3] := 0;
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Mb[3, 4] := 0;
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Mb[4, 1] := 1;
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Mb[4, 2] := 0;
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Mb[4, 3] := 0;
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Mb[4, 4] := 0;
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end;
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begin
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set_BezMat;
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getPoints;
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matmlt(Cx, Mb, Px, 4, 1);
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matmlt(Cy, Mb, Py, 4, 1);
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t := -0.01;
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xx := round(Px[1, 1]);
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yy := round(Py[1, 1]);
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Moveto(xx, yy);
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ForeColor(137); {Set pen to magenta.}
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for i := 1 to 101 do
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begin
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t := t + 0.01;
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Tv[1, 4] := 1;
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Tv[1, 3] := t * Tv[1, 4];
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Tv[1, 2] := t * Tv[1, 3];
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Tv[1, 1] := t * Tv[1, 2];
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matmlt(x, Tv, Cx, 1, 1);
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matmlt(y, Tv, Cy, 1, 1);
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xx := round(x[1, 1]);
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yy := round(y[1, 1]);
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Lineto(xx, yy);
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end;
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end. |