Octopus Tentacles: Bgrabmp ellipse too slow but GL does it

[Boleeman]

Hi all.

I tried making an octopus tentacles animation but I am finding the movement of the tentacles very sluggish.

The alpha changes as the tentacles sway.

Not sure how to improve the speed of the tentacles movement to make a hypnotic movement?

[Gigatron]

Hi all.

I tried making an octopus tentacles animation but I am finding the movement of the tentacles very sluggish.

The alpha changes as the tentacles sway.

Not sure how to improve the speed of the tentacles movement to make a hypnotic movement?

Nice @Boleeman

To test the glCanvas quick conversion to gl version of this cool fx;

Regards

[Thaddy]

Nice!
Nice conversion to glcanvas too...

[Boleeman]

Wow GigaTron.

Looks like GL is the way to go for Ellipse animations.
That's the exact effect that I was trying to achieve.

For some reasonTBgrabmp does not handle ellipse animations well, but its really good at stationary renders.

Thanks Gigatron.

[Boleeman]

Actually Gigtron, not sure if you could possibly help with another ellipse animation?

I had another project of a Burning sun that uses ellipses, but it also has Canvas2D to do ctx.Translate(x, y);
Not sure if you could possibly work out how to do it in GL?

The effect should be a really nice trippy burning Sun, but I could not get this to animate properly.

[Gigatron]

Actually Gigtron, not sure if you could possibly help with another ellipse animation?

I had another project of a Burning sun that uses ellipses, but it also has Canvas2D to do ctx.Translate(x, y);
Not sure if you could possibly work out how to do it in GL?

The effect should be a really nice trippy burning Sun, but I could not get this to animate properly.

Hi, i have not all gl functions to translate rotate like ctx Canvas2D; but this conversion is not bad i think;

Regards

[Gigatron]

Hi

With the new version of the glcanvas  the code is more understandable and easy,
support of ctx.save, ctx.restore, ctx.translate, ctx.rotate + 3D cubes ;

glSaveMatrix;
glRestoreMatrix;
glTranslateMatrix(rayX, rayY, 0);
glRotateMatrix(-i + rot, 0, 0, 1); // Z rotation   

Code: Pascal  [Select][+][-]

1. unit Unit1;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.   Classes, SysUtils, Forms, Controls, Graphics, Dialogs, ExtCtrls,
9.   OpenGLContext, Math, glcanvas;
10.  
11. type
12.   { TForm1 }
13.   TForm1 = class(TForm)
14.     OpenGLControl1: TOpenGLControl;
15.     Panel1: TPanel;
16.     Timer1: TTimer;
17.     procedure FormCreate(Sender: TObject);
18.     procedure OpenGLControl1Paint(Sender: TObject);
19.     procedure Timer1Timer(Sender: TObject);
20.   private
21.     num, rot: Single;
22.   public
23.   end;
24.  
25. var
26.   Form1: TForm1;
27.  
28. implementation
29.  
30. {$R *.lfm}
31.  
32. { TForm1 }
33.  
34. procedure TForm1.Timer1Timer(Sender: TObject);
35. begin
36.   OpenGLControl1.Invalidate;
37. end;
38.  
39. procedure TForm1.FormCreate(Sender: TObject);
40. begin
41.   glInit(OpenGLControl1);
42.   if not OpenGLControl1.MakeCurrent then raise Exception.Create('OpenGL context makeCurrent Error');
43.   num := 0;
44.   rot := 0;
45. end;
46.  
47. procedure TForm1.OpenGLControl1Paint(Sender: TObject);
48. var
49.   i, q: Integer;
50.   a, d: Single;
51.   cx, cy: Integer;
52.   rayX, rayY: Single;
53. begin
54.   if not OpenGLControl1.MakeCurrent then Exit;
55.   glFillScreen(OpenGLControl1, 0.0, 0.0, 0.0, 1.0);
56.  
57.   cx := OpenGLControl1.Width div 2;
58.   cy := OpenGLControl1.Height div 2;
59.  
60.   glSaveMatrix;                    // sun
61.   glTranslateMatrix(cx, cy, 0);
62.  
63.   for i := -180 to 179 do
64.     if i mod 12 = 0 then
65.     begin
66.       rayX := sin(DegToRad(i)) * 15;
67.       rayY := cos(DegToRad(i)) * 15;
68.  
69.       glSaveMatrix;
70.       glTranslateMatrix(rayX, rayY, 0);
71.       glRotateMatrix(-i + rot, 0, 0, 1); // Z rotation
72.  
73.       for q := 0 to 195 do
74.         if q mod 5 = 0 then
75.         begin
76.           d := 40 - (q / 200) * 40;
77.           a := sin(DegToRad(-i + q + num)) * 2;
78.           glEllipse(a, q * 1.7, d, d, 20, 1.0, 0.6, 0.0, 0.1, true);
79.         end;
80.  
81.       glRestoreMatrix;    // rays
82.     end;
83.  
84.   glRestoreMatrix;  // sun
85.   glSaveMatrix;
86.   glFilled3DCube(OpenGLControl1, -80, 0, 0,  50, 1.0, 1.0, 1.0, 1.0, rot, -rot, rot, 0.0, 0.0, 1.0);
87.   glWired3DCube(OpenGLControl1,  -80, 0, 0,  50, 1.0,0.0,0.0, 1.0, rot, -rot, rot, 4.0);
88.   glRestoreMatrix;
89.   glFilled3DCube(OpenGLControl1, 80, 0, 0, 50, 0.0,0.5,1.0, 1.0, rot, rot, rot, 1.0, 0.0, 0.0);
90.   glWired3DCube(OpenGLControl1, 80, 0, 0,  50, 0.5,0.5,0.5, 1.0, rot, rot, rot, 4.0);
91.   num += 11.5;  // deg
92.   rot += 1.15;  // deg
93.  
94.   OpenGLControl1.SwapBuffers;
95. end;
96.  
97. end.

 

[Boleeman]

Thanks for helping out Gigatron.


I used a := sin(DegToRad(-i + q + num)) * 10; to make the rendering wobble a bit more.
Now need to try to make an alpha trail from the vertices to make it look like heat is coming from it, like a heat trail from the Sun.

I will need to learn a bit more about GL from your latest code.

Wondered if GL also does conic gradient? as TBgrabmp only has linear and radial gradient.

Thanks Gigatron for your help.