//------------------------------- Experiments in Moving Text along the Screen
//
//  Produces interesting effects if the render and erase operations are out
//  of sync or if the render and erase texts are different.
//
//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop

#include "Unit1.h"
#include <math.h>
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;

// initial variables for each move type
int down=0;           // counter for the down timer
int diag=0;           // counter for the diagonal timer
int freefall=0;           // counter for the freefall timer
int dis=0;         // counter for the disintegration timer
int alpha[14];     // the vertical position of each character
int delay[14];     // random delay for each letter
int start=30;      // time before disintegration begins
int last[14];      // the vertical position of the last render
// gravitational variabiles
int s=0;       // distance
int a=2;       // acceleration
int t=0;       // time
int lasts=0;   // last value of s

//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
   : TForm(Owner)
{
   // Sets the background of the text to transparent.
   Form1->Canvas->Brush->Style = bsClear;
   randomize();
}

//---------------------------------------------------------------- Down Timer
//----------------------------------------- Moves Down at a Constant Velocity
void __fastcall TForm1::TimerDownTimer(TObject *Sender)
{
   down++;
   down++;
   // backs up to erase previous text
   if (down>1) {
      Form1->Canvas->Font->Color=clBtnFace;
      Form1->Canvas->TextOut(150, down-2, "Lower me down.");
   }
   // moves forward to render new text
   Form1->Canvas->Font->Color=clBlack;
   Form1->Canvas->TextOut(150, down, "Lower me down.");
   // quit
   if (down==300) Form1->TimerDown->Enabled=false;
}

//------------------------------------------------------------ Diagonal Timer
//------------------------ Moves Down and to the Right at a Constant Velocity
void __fastcall TForm1::TimerDiagonallyTimer(TObject *Sender)
{
   diag++;
   diag++;
   // backs up to erase previous text
   if (diag>1) {
      Form1->Canvas->Font->Color=clBtnFace;
      Form1->Canvas->TextOut(diag-2, diag-2, "I move diagonally.");
   }
   // moves forward to render new text
   Form1->Canvas->Font->Color=clBlack;
   Form1->Canvas->TextOut(diag, diag, "I move diagonally.");
   // quit
   if (diag==300) Form1->TimerDiagonally->Enabled=false;
}

//----------------------------------------------------------- Free Fall Timer
//------------------------------------------ Simulates Gravitational FreeFall
void __fastcall TForm1::TimerFreeFallTimer(TObject *Sender)
{
   freefall++;
   // backs up to erase previous text
   if (freefall>1) {
      Form1->Canvas->Font->Color=clBtnFace;
      Form1->Canvas->TextOut(200, lasts, "Watch me fall.");
   }
   s = (a * freefall * freefall) / 2;  // s=1/2(at^2)
   // moves forward to render new text
   Form1->Canvas->Font->Color=clBlack;
   Form1->Canvas->TextOut(200, s, "Watch me fall.");
   // quit
   if (s>=300) Form1->TimerFreeFall->Enabled=false;
   lasts=s;
}

//------------------------------------------------------ Disintegration Timer
//--------------------------------------------- Simulates Disintegrating Text
void __fastcall TForm1::TimerDisintegrationTimer(TObject *Sender)
{
   dis++;
   Form1->Canvas->Font->Color=clBlack;

   if (dis>delay[0]) {
      if (dis>delay[0]) {
         Form1->Canvas->Font->Color=clBtnFace;
         Form1->Canvas->TextOut(10, last[0], "D");
     }
      Form1->Canvas->Font->Color=clBlack;
      alpha[0] = (a * pow(dis-delay[0], 2)) / 2;
      Form1->Canvas->TextOut(10, alpha[0], "D");
      last[0]=alpha[0];
   }

   if (dis>delay[1]) {
      if (dis>delay[1]) {
         Form1->Canvas->Font->Color=clBtnFace;
         Form1->Canvas->TextOut(25, last[1], "i");
     }
      Form1->Canvas->Font->Color=clBlack;
      alpha[1] = (a * pow(dis-delay[1], 2)) / 2;
      Form1->Canvas->TextOut(25, alpha[1], "i");
      last[1]=alpha[1];
   }

   if (dis>delay[2]) {
      if (dis>delay[2]) {
         Form1->Canvas->Font->Color=clBtnFace;
         Form1->Canvas->TextOut(32, last[2], "s");
     }
      Form1->Canvas->Font->Color=clBlack;
      alpha[2] = (a * pow(dis-delay[2], 2)) / 2;
      Form1->Canvas->TextOut(32, alpha[2], "s");
      last[2]=alpha[2];
   }

   if (dis>delay[3]) {
      if (dis>delay[3]) {
         Form1->Canvas->Font->Color=clBtnFace;
         Form1->Canvas->TextOut(40, last[3], "i");
     }
      Form1->Canvas->Font->Color=clBlack;
      alpha[3] = (a * pow(dis-delay[3], 2)) / 2;
      Form1->Canvas->TextOut(40, alpha[3], "i");
      last[3]=alpha[3];
   }

   if (dis>delay[4]) {
      if (dis>delay[4]) {
         Form1->Canvas->Font->Color=clBtnFace;
         Form1->Canvas->TextOut(47, last[4], "n");
     }
      Form1->Canvas->Font->Color=clBlack;
      alpha[4] = (a * pow(dis-delay[4], 2)) / 2;
      Form1->Canvas->TextOut(47, alpha[4], "n");
      last[4]=alpha[4];
   }

   if (dis>delay[5]) {
      if (dis>delay[5]) {
         Form1->Canvas->Font->Color=clBtnFace;
         Form1->Canvas->TextOut(60, last[5], "t");
     }
      Form1->Canvas->Font->Color=clBlack;
      alpha[5] = (a * pow(dis-delay[5], 2)) / 2;
      Form1->Canvas->TextOut(60, alpha[5], "t");
      last[5]=alpha[5];
   }

   if (dis>delay[6]) {
      if (dis>delay[6]) {
         Form1->Canvas->Font->Color=clBtnFace;
         Form1->Canvas->TextOut(68, last[6], "e");
     }
      Form1->Canvas->Font->Color=clBlack;
      alpha[6] = (a * pow(dis-delay[6], 2)) / 2;
      Form1->Canvas->TextOut(68, alpha[6], "e");
      last[6]=alpha[6];
   }

   if (dis>delay[7]) {
      if (dis>delay[7]) {
         Form1->Canvas->Font->Color=clBtnFace;
         Form1->Canvas->TextOut(78, last[7], "g");
     }
      Form1->Canvas->Font->Color=clBlack;
      alpha[7] = (a * pow(dis-delay[7], 2)) / 2;
      Form1->Canvas->TextOut(78, alpha[7], "g");
      last[7]=alpha[7];
   }

   if (dis>delay[8]) {
      if (dis>delay[8]) {
         Form1->Canvas->Font->Color=clBtnFace;
         Form1->Canvas->TextOut(90, last[8], "r");
     }
      Form1->Canvas->Font->Color=clBlack;
      alpha[8] = (a * pow(dis-delay[8], 2)) / 2;
      Form1->Canvas->TextOut(90, alpha[8], "r");
      last[8]=alpha[8];
   }

   if (dis>delay[9]) {
      if (dis>delay[9]) {
         Form1->Canvas->Font->Color=clBtnFace;
         Form1->Canvas->TextOut(100, last[9], "ax");
     }
      Form1->Canvas->Font->Color=clBlack;
      alpha[9] = (a * pow(dis-delay[9], 2)) / 2;
      Form1->Canvas->TextOut(100, alpha[9], "a");
      last[9]=alpha[9];
   }

   if (dis>delay[10]) {
      if (dis>delay[10]) {
         Form1->Canvas->Font->Color=clBtnFace;
         Form1->Canvas->TextOut(110, last[10], "t");
     }
      Form1->Canvas->Font->Color=clBlack;
      alpha[10] = (a * pow(dis-delay[10], 2)) / 2;
      Form1->Canvas->TextOut(110, alpha[10], "t");
      last[10]=alpha[10];
   }

   if (dis>delay[11]) {
      if (dis>delay[11]) {
         Form1->Canvas->Font->Color=clBtnFace;
         Form1->Canvas->TextOut(118, last[11], "i");
     }
      Form1->Canvas->Font->Color=clBlack;
      alpha[11] = (a * pow(dis-delay[11], 2)) / 2;
      Form1->Canvas->TextOut(118, alpha[11], "i");
      last[11]=alpha[11];
   }

   if (dis>delay[12]) {
      if (dis>delay[12]) {
         Form1->Canvas->Font->Color=clBtnFace;
         Form1->Canvas->TextOut(125, last[12], "o");
     }
      Form1->Canvas->Font->Color=clBlack;
      alpha[12] = (a * pow(dis-delay[12], 2)) / 2;
      Form1->Canvas->TextOut(125, alpha[12], "o");
      last[12]=alpha[12];
   }

   if (dis>delay[13]) {
      if (dis>delay[13]) {
         Form1->Canvas->Font->Color=clBtnFace;
         Form1->Canvas->TextOut(136, last[13], "n");
     }
      Form1->Canvas->Font->Color=clBlack;
      alpha[13] = (a * pow(dis-delay[13], 2)) / 2;
      Form1->Canvas->TextOut(136, alpha[13], "n");
      last[13]=alpha[13];
   }

   if (dis>=300) Form1->TimerDisintegration->Enabled=false;
}
//-------------------------------------------------------------- Clear Button
//------------------------------------------------------------- Clears Screen
void __fastcall TForm1::ButtonClearClick(TObject *Sender)
{
   Refresh();
}

//--------------------------------------------------------------- Down Button
//--------------------------------------------------------- Starts Down Timer
void __fastcall TForm1::ButtonDownClick(TObject *Sender)
{
   Form1->TimerDown->Enabled=true;
   down=0;
}

//----------------------------------------------------------- Diagonal Button
//----------------------------------------------------- Starts Diagonal Timer
void __fastcall TForm1::ButtonDiagonallyClick(TObject *Sender)
{
   diag=0;
   Form1->TimerDiagonally->Enabled=true;
}

//--------------------------------------------------------------- Both Button
//-------------------------------------- Starts Both Diagonal and Down Timers
void __fastcall TForm1::ButtonBothClick(TObject *Sender)
{
   diag=0;
   Form1->TimerDiagonally->Enabled=true;
   down=0;
   Form1->TimerDown->Enabled=true;
}

//--------------------------------------------------------------- Drop Button
//----------------------------------------------------- Starts FreeFall Timer
void __fastcall TForm1::ButtonFreeFallClick(TObject *Sender)
{
   freefall=0;
   Form1->TimerFreeFall->Enabled=true;
}

//----------------------------------------------------- Disintegration Button
//----------------------------------------------- Starts Disintegration Timer

void __fastcall TForm1::ButtonDisintegrationClick(TObject *Sender)
{
   dis=0;
   // Sets the time before falling for each letter
   for (int i=0; i<14; i++) {
      alpha[i]=0;
      last[i]=0;
      delay[i]=start+random(50);
   }   
   // Renders each letter of the text in its top position
   Form1->Canvas->Font->Color=clBlack;
   Form1->Canvas->TextOut(10, 0, "D");
   Form1->Canvas->TextOut(25, 0, "i");
   Form1->Canvas->TextOut(32, 0, "s");
   Form1->Canvas->TextOut(40, 0, "i");
   Form1->Canvas->TextOut(47, 0, "n");
   Form1->Canvas->TextOut(60, 0, "t");
   Form1->Canvas->TextOut(68, 0, "e");
   Form1->Canvas->TextOut(78, 0, "g");
   Form1->Canvas->TextOut(90, 0, "r");
   Form1->Canvas->TextOut(100, 0, "a");
   Form1->Canvas->TextOut(110, 0, "t");
   Form1->Canvas->TextOut(118, 0, "i");
   Form1->Canvas->TextOut(125, 0, "o");
   Form1->Canvas->TextOut(136, 0, "n");
   Form1->TimerDisintegration->Enabled=true;
}
//---------------------------------------------------------------------------


void __fastcall TForm1::ButtonStopClick(TObject *Sender)
{
   TimerDown->Enabled=false;
   TimerDiagonally->Enabled=false;
   TimerFreeFall->Enabled=false;
   TimerDisintegration->Enabled=false;
}
//---------------------------------------------------------------------------