treewars/drawutils.cpp

#include "drawutils.h"
#include <cmath>

SDL_Surface* DrawUtils::load(string file)
{
    SDL_Surface* raw = NULL;
    SDL_Surface* cooked = NULL;

    raw = SDL_LoadBMP(file.c_str());
    if (raw == NULL) return NULL;

    cooked = SDL_DisplayFormat(raw);
    SDL_FreeSurface(raw); // don't consume raw surfaces

    return cooked;
}


bool DrawUtils::draw(SDL_Surface* dest, SDL_Surface* drawable, int x, int y)
{
    if (dest == NULL || drawable == NULL) return false;

    SDL_Rect dest_r;

    dest_r.x = x;
    dest_r.y = y;

    SDL_BlitSurface(drawable, NULL, dest, &dest_r);

    return true;
}


bool DrawUtils::draw(SDL_Surface* dest, SDL_Surface* drawable, int x, int y, 
		     int x2, int y2, int w, int h)
{
    SDL_Rect dest_r;

    dest_r.x = x;
    dest_r.y = y;

    SDL_Rect src_r;

    src_r.x = x2;
    src_r.y = y2;
    src_r.w = w;
    src_r.h = h;

    SDL_BlitSurface(drawable, &src_r, dest, &dest_r);

    return true;
}

void DrawUtils::draw_line(Sint16 x1, Sint16 y1, Sint16 x2, Sint16 y2, Uint16 width, Uint32 colour, SDL_Surface* dest)
{
    float dx, dy, len;
    float cx, cy; // our current coords

    SDL_Rect pen;

    dx = static_cast<float>(x2-x1);
    dy = static_cast<float>(y2-y1);

    len = sqrt(dx*dx + dy*dy);

    // changing dx and dy's meanings. Now they represent the amount we move
    // each step in our drawing loop
    dx /= len;
    dy /= len;

    int j = static_cast<int>(len);

    cx = static_cast<float>(x1 - (width>>1));
    cy = static_cast<float>(y1 - (width>>1));

    int i;
    for(i = 0; i < j; i++)
    {
	pen.x = (Sint16)cx;
	pen.y = (Sint16)cy;
	pen.w = width;
	pen.h = width;

	SDL_FillRect(dest, &pen, colour);

	cx += dx;
	cy += dy;
    }
}