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Examples/sprites: Add smooth movement of sprite by keyboard, as well as interia effect for keyboard movement (code by Handoko, https://forum.lazarus.freepascal.org/index.php/topic,41178.msg285678.html#msg285678).

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git-svn-id: trunk@57899 -
This commit is contained in:
wp 2018-05-11 17:05:38 +00:00
parent 9997fa404c
commit 7b4fa8c326
2 changed files with 42 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
examples/sprites/playground.lfm
View File

@ -66,8 +66,10 @@ object PlayGroundForm: TPlayGroundForm
ItemIndex = 0 ItemIndex = 0
Items.Strings = ( Items.Strings = (
'code' 'code'
'arrow keys'
'mouse' 'mouse'
'arrow keys'
'arrow keys (smooth)'
'arrow keys with inertia'
) )
OnChange = ComboBox1Change OnChange = ComboBox1Change
Style = csDropDownList Style = csDropDownList
@ -77,7 +79,7 @@ object PlayGroundForm: TPlayGroundForm
end end
object Timer1: TTimer object Timer1: TTimer
Enabled = False Enabled = False
Interval = 100 Interval = 40
OnTimer = Timer1Timer OnTimer = Timer1Timer
left = 164 left = 164
top = 49 top = 49

46
examples/sprites/playground.pas
View File

@ -6,7 +6,7 @@ interface
uses uses
Classes, SysUtils, LResources, Forms, Controls, Graphics, Dialogs, Classes, SysUtils, LResources, Forms, Controls, Graphics, Dialogs,
LMessages, LCLType, ExtCtrls, StdCtrls; LMessages, LCLType, LCLIntf, ExtCtrls, StdCtrls;
type type
@ -48,6 +48,8 @@ type
procedure PictureControlKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState); procedure PictureControlKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
procedure Timer1Timer(Sender: TObject); procedure Timer1Timer(Sender: TObject);
private private
FXIntertia: Double;
FYIntertia: Double;
FSpritePos: TPoint; FSpritePos: TPoint;
FSpritePosChange: TPoint; FSpritePosChange: TPoint;
FSpritePosInit: Boolean; FSpritePosInit: Boolean;
@ -89,6 +91,9 @@ begin
BufferImg.Width:=BackgroundImg.Width; BufferImg.Width:=BackgroundImg.Width;
BufferImg.Height:=BackgroundImg.Height; BufferImg.Height:=BackgroundImg.Height;
FXIntertia := 0;
FYIntertia := 0;
Timer1.Enabled := Combobox1.ItemIndex = 0; Timer1.Enabled := Combobox1.ItemIndex = 0;
UpdateImage; UpdateImage;
@ -115,7 +120,7 @@ end;
procedure TPlayGroundForm.ComboBox1Change(Sender: TObject); procedure TPlayGroundForm.ComboBox1Change(Sender: TObject);
begin begin
Timer1.Enabled := Combobox1.ItemIndex in [0, 2]; Timer1.Enabled := Combobox1.ItemIndex in [0, 1, 3, 4];
PictureControl.SetFocus; PictureControl.SetFocus;
end; end;
@ -124,6 +129,7 @@ procedure TPlayGroundForm.PictureControlKeyDown(Sender: TObject;
const const
DELTA = 20; DELTA = 20;
begin begin
if ComboBox1.ItemIndex = 3 then Exit; // for smooth arrow key input
case Key of case Key of
VK_LEFT : FSpritePosChange := Point(-DELTA, 0); VK_LEFT : FSpritePosChange := Point(-DELTA, 0);
VK_RIGHT : FSpritePosChange := Point( DELTA, 0); VK_RIGHT : FSpritePosChange := Point( DELTA, 0);
@ -197,12 +203,6 @@ begin
FSpritePos.Y := CenterY + round(sin(t*0.7)*CenterY*2/3) - SpriteImg.Height div 2; FSpritePos.Y := CenterY + round(sin(t*0.7)*CenterY*2/3) - SpriteImg.Height div 2;
end; end;
1: begin 1: begin
// Movement of sprite by keyboard: UP/DOWN/LEFT/RIGHT arrows advance
// the sprite position by a given amount
FSpritePos.X := FSpritePos.X + FSpritePosChange.X;
FSpritePos.Y := FSpritePos.Y + FSpritePosChange.Y;
end;
2: begin
// Movement of sprite by mouse: the sprite follows the mouse // Movement of sprite by mouse: the sprite follows the mouse
// Convert screen coordinates to images coordinates // Convert screen coordinates to images coordinates
MousePos := PictureControl.ScreenToClient(Mouse.CursorPos); MousePos := PictureControl.ScreenToClient(Mouse.CursorPos);
@ -213,6 +213,36 @@ begin
FSpritePos.X := FSpritePos.X + dx; FSpritePos.X := FSpritePos.X + dx;
FSpritePos.Y := FSpritePos.Y + dy; FSpritePos.Y := FSpritePos.Y + dy;
end; end;
2: begin
// Movement of sprite by keyboard: UP/DOWN/LEFT/RIGHT arrows advance
// the sprite position by a given amount
FSpritePos.X := FSpritePos.X + FSpritePosChange.X;
FSpritePos.Y := FSpritePos.Y + FSpritePosChange.Y;
end;
3: begin
// Movement of sprite by keyboard: UP/DOWN/LEFT/RIGHT arrows advance smooth version
if (GetKeyState(VK_LEFT) < 0) then FSpritePos.X := FSpritePos.X - 10;
if (GetKeyState(VK_RIGHT) < 0) then FSpritePos.X := FSpritePos.X + 10;
if (GetKeyState(VK_UP) < 0) then FSpritePos.Y := FSpritePos.Y - 10;
if (GetKeyState(VK_DOWN) < 0) then FSpritePos.Y := FSpritePos.Y + 10;
end;
4: begin
// Movement of sprite by keyboard: UP/DOWN/LEFT/RIGHT arrows advance with inertia
if (GetKeyState(VK_LEFT) < 0) then FXIntertia := FXIntertia - 0.5;
if (GetKeyState(VK_RIGHT) < 0) then FXIntertia := FXIntertia + 0.5;
if (GetKeyState(VK_UP) < 0) then FYIntertia := FYIntertia - 0.5;
if (GetKeyState(VK_DOWN) < 0) then FYIntertia := FYIntertia + 0.5;
if (FXIntertia > 6) then FXIntertia := 6;
if (FXIntertia < -6) then FXIntertia := -6;
if (FYIntertia > 6) then FYIntertia := 6;
if (FYIntertia < -6) then FYIntertia := -6;
if (FXIntertia > 0) then FXIntertia := FXIntertia - 0.2;
if (FXIntertia < 0) then FXIntertia := FXIntertia + 0.2;
if (FYIntertia > 0) then FYIntertia := FYIntertia - 0.2;
if (FYIntertia < 0) then FYIntertia := FYIntertia + 0.2;
FSpritePos.X := FSpritePos.X + round(FXIntertia);
FSpritePos.Y := FSpritePos.Y + round(FYIntertia);
end;
end; end;
// Make sure that the sprite does not leave the image. // Make sure that the sprite does not leave the image.