// Template, major revision 3, beta
// IGAD/NHTV - Jacco Bikker - 2006-2009

#include "string.h"
#include "game.h"
#include "surface.h"
#include "stdlib.h"
#include "template.h"
#include <assert.h>

using namespace Tmpl8;

DWORD startTicks = ::GetTickCount();
DWORD elapsedTicks = 0;
int numFrames=0;

void Game::Init()
{
    m_WobbleAngle = 0.0;
    m_Image = new Surface( "vidink.tga" );
}

void Game::Wobble( float angle )
{
    assert( m_Surface->GetPitch() == m_Surface->GetWidth() );       // if the buffer width and pixel width are not the same, the following code will not work because it assumes they are!
    assert( m_Image->GetPitch() == m_Image->GetWidth() );

    Pixel* dstPtr ;
    Pixel* srcPtr;
    int x;
    int y;
    float imX;
    float imY;
    unsigned int imXi;
    unsigned int imYi;

    float Yangle;
    float Xangle;

    Yangle = angle;

    dstPtr = m_Surface->GetBuffer();
    srcPtr = m_Image->GetBuffer();

    const float wobbleSize = 7.0f;
    const float angleIncrement = 0.01f;

    //****************************************
    // HA1 - start making assembler HERE
    //****************************************

#define ASSEMBLER
#ifndef ASSEMBLER
    for( y=0; y<SCRHEIGHT; y++ )
    {
        Xangle = Yangle;
        for( x=0;x<SCRWIDTH; x++ )
        {
            imX = (float)x + sin(Xangle) * wobbleSize;
            imY = (float)y + cos(Xangle) * wobbleSize;

            imXi = (unsigned int) (imX);
            imYi = (unsigned int) (imY);

            imXi &= 511;    // same as imXi %= 512 (512 is width of the bitmap), but faster
            imYi &= 511;    // same as imYi %= 512 (512 is height of the bitmap), but faster

            *dstPtr++ = srcPtr[ imYi*512 + imXi];   // set screen pixel to rotated and modulo'd rotated bitmap pixel

            Xangle += angleIncrement;
        }

        Yangle += angleIncrement;
    }

#else

__asm{
    //Push eax, ebx and ecx to preserve them
    //not sure if this is needed, but o well can't hurt
    push eax
    push ebx
    push ecx
    xor eax, eax

    //for( y=0; y<SCRHEIGHT; y++ )
    mov y, eax //eax = 0
yloop:
        //Xangle = Yangle
        push dword ptr [Yangle]
        pop dword ptr [Xangle]

        //for( x=0;x<SCRWIDTH; x++  )
        mov x, eax //eax = 0
        xloop:
                fld dword ptr [Xangle]      //Load Xangle in ST(0)
                fsincos                     //ST(0) = Sin(Xangle) and ST(1) = Cos(Xangle)
                //fld st(0)                 //ST(3) = ST(0)
                //fld dword ptr [wobbleSize]  //ST(0) = wobbleSize

                fmul dword ptr [wobbleSize] //ST(0) = ST(0) * wobbleSize
                fiadd dword ptr[x]          //ST(0) = ST(0)+ x
                fistp dword ptr[imXi]       //imXi = rounded integer of ST(0)  and ST(0) = ST(1)

                fmul dword ptr [wobbleSize] //FPU = FPU * wobbleSize
                fiadd dword ptr[y]          //FPU = y + FPU
                fistp dword ptr[imYi]       //imXi = rounded integer of ST(0)

                //imX = (float)x + sin(Xangle) * wobbleSize
                /*fld dword ptr [Xangle]        //FPU = Xangle
                fsin                            //FPU = sin(Xangle)
                fmul dword ptr [wobbleSize] //FPU = FPU * wobbleSize
                fiadd dword ptr[x]          //FPU = x + FPU
                //fst dword ptr[imX]            //imX = FPU
                //imXi = (unsigned int) (FPU);
                fistp dword ptr[imXi]           //imXi = rounded integer of FPU

                //imY = (float)y + cos(Xangle) * wobbleSize
                fld dword ptr [Xangle]      //FPU = Xangle
                fcos                            //FPU = cos(Xangle)
                fmul dword ptr [wobbleSize] //FPU = FPU * wobbleSize
                fiadd dword ptr[y]          //FPU = y + FPU
                //fst dword ptr[imY]            //imY = FPU
                //imYi = (unsigned int) (FPU);
                fistp dword ptr[imYi]           //imYi = rounded integer of FPU*/

                //imXi &= 511;
                mov eax, dword ptr [imXi]
                and eax, 511
                mov dword ptr [imXi], eax

                //imYi &= 511;
                mov eax, dword ptr [imYi]
                and eax, 511
                mov dword ptr [imYi], eax

                //imYi*512 + imXi
                mov eax, dword ptr [imYi]
                shl eax, 9
                add eax, dword ptr [imXi]

                //*dstPtr = srcPtr[ imYi*512 + imXi];
                mov ebx, dword ptr[srcPtr]
                mov eax, dword ptr [ebx+eax*4]
                mov ebx, dword ptr[dstPtr]
                mov dword ptr [ebx], eax

                //dstPtr++
                add dstPtr, 4

                //Xangle += angleIncrement;
                fld dword ptr [angleIncrement]
                fadd dword ptr [Xangle]
                fstp dword ptr [Xangle]

                //x<SCRWIDTH
                mov eax, x
                sub eax, SCRWIDTH-1
                jz endxloop //jump out of the loop if x == SCRWIDTH
                inc x
                jmp xloop
        endxloop:

        //Yangle += angleIncrement;
        fld Yangle
        fadd angleIncrement
        fstp Yangle

        //y<SCRHEIGHT
        mov eax, y
        sub eax, SCRHEIGHT-1
        jz endyloop //jump out of the loop if x == SCRWIDTH
        inc y
        xor eax, eax //eax = 0
        jmp yloop
endyloop:

    //Pop eax, ebx and ecx back from the stack to restore
    pop ecx
    pop ebx
    pop eax

}
#endif



    //****************************************
    // HA1 - stop making assembler HERE
    //****************************************
}

void Game::Tick( float a_DT )
{
    numFrames++;
    m_WobbleAngle += (double) a_DT * 0.01;

    Wobble( (float)m_WobbleAngle );

    if(numFrames == 100)
    {
        elapsedTicks = ::GetTickCount() - startTicks;
        float fps = (float) numFrames / ((float) elapsedTicks / 1000.0f );

        char tmps[256];
        sprintf(tmps,"Average FPS: %f",fps);
        MessageBox(NULL, tmps, "report", MB_OK );
    }
}