Minor C++ programming question

Chada

Hey guys,

I'm after some assistance if possible to do with a selection class im creating for a real time strategy game (2d).

This might be a bit long code wise sorry! :


#ifndef SELECTION_H
#define SELECTION_H

#include "SDL/SDL.h"

struct Point2D
{
double getX() const {return mX;}
double getY() const {return mY;}
void setX(double x) {mX = x;}
void setY(double y) {mY = y;}
void setXY(double x, double y) {setX(x); setY(y);}

private:

double mX, mY;

}; // end point2d struct


struct Area
{

Area() { setAll(0, 0, 0, 0); }

void setLeft(int left)
{
mLeft = left;
if(mLeft > mRight)
swap(mLeft, mRight);
}

void setTop(int top)
{
mTop = top;
if(mTop > mBottom)
swap(mTop, mBottom);
}

void setRight(int right)
{
mRight = right;
if(mRight < mLeft)
swap(mRight, mLeft);
}

void setBottom(int bottom)
{
mBottom = bottom;
if(mBottom < mTop)
swap(mBottom, mTop);
}

void setAll(int left, int top, int right, int bottom)
{
mLeft = left;
mTop = top;
setRight(right);
setBottom(bottom);
}


int left() const { return mLeft; }
int top() const { return mTop; }
int right() const { return mRight; }
int bottom() const { return mBottom; }

private:

int mLeft, mTop, mRight, mBottom;

void swap(int& a, int& b)
{
int c = a;
a = b;
b = c;
}
};

class Selection
{

private:

enum SelectionStates { NOT_SELECTING, SELECTING };
SelectionStates state;
//int mouseX, mouseY;
Uint8 mouseState;


public:

Area selection;
Point2D location;
Selection();
bool update();
void render( SDL_Surface *screen );


}; // end selection.h

#endif

OK thats my header file! Heres my selection.cpp >>>

#include "selection.h"
#include <iostream>
#include <stdlib.h>
#include <SDL/SDL.h>
#include <SDL/SDL_gfxPrimitives.h>

Selection::Selection()
{
state = NOT_SELECTING;
}


bool Selection::update()
{
int mouseX, mouseY;
Uint8 mouseState = SDL_GetMouseState( &mouseX, &mouseY );
if( state == SELECTING ) {
if( !( mouseState & SDL_BUTTON(1) ) ) {
state = NOT_SELECTING;
return true;
} else {
selection.setLeft( mouseX );
selection.setTop( mouseY );
}
} else {
if( mouseState & SDL_BUTTON(1) ) {
state = SELECTING;
selection.setLeft( mouseX );
selection.setTop( mouseY );
selection.setRight( mouseX );
selection.setBottom( mouseY );


}
}

return false;

}


void Selection::render( SDL_Surface *screen )
{
if( state == SELECTING )
{
rectangleColor( screen, selection.left(), selection.top(), selection.right(), selection.bottom(), 0xfe00008b);
}
}


>>> THe problem im experiencing is that my rectangleColor() function (which is a preset from sdl_gfx library) is drawing a rectangle which is good, but the initial x, y coordinates (i.e. left and top) are stuck at (0,0) and don't move no matter where i click, but the right and bottom coordinates are correctly drawing as the bottom right hand corner of the rectangle ( as specified when i click the mouse button). Basically when i click on the mouse intially the x and y coords of the mouse sud be left() and top() but they are turning into right() and bottom() and the left and top are stuck at 0,0.

Am i missing out on some really basic mathematical mistake ? My brain is just fried and if anyone can lend a hand and point out my mistake i would be greatly appreciated!


Sorry for long post,

dan.

Chada

Is no-one able to help ?

Im really stuck here cant see where ive went wrong!

satchmo

Try using the [code] tags to make it readable, people might be more willing to have a look then.