libcaca/examples/trifiller.c

/*
 *  trifiller     texture mapping features
 *  Copyright (c) 2009 Jean-Yves Lamoureux <jylam@lnxscene.org>
 *                All Rights Reserved
 *
 *  $Id: trifiller.c 2821 2008-09-27 13:12:46Z sam $
 *
 *  This program is free software. It comes without any warranty, to
 *  the extent permitted by applicable law. You can redistribute it
 *  and/or modify it under the terms of the Do What The Fuck You Want
 *  To Public License, Version 2, as published by Sam Hocevar. See
 *  http://sam.zoy.org/wtfpl/COPYING for more details.
 */


#include "config.h"

#if !defined(__KERNEL__)
#   include <stdio.h>
#   include <string.h>
#endif

/* libcaca header */
#include "caca.h"

/* Image loading functions */
#include "../src/common-image.h"

/* M_PI / cos / sin */
#include <math.h> 


#define SQUARE_SIZE 20

int main(int argc, char *argv[])
{
    
    /* libcaca/libcaca contexts */
    caca_canvas_t *cv; caca_display_t *dp;
    caca_canvas_t *tex;
    
    /* cached canvas size */
    int ww, wh, tw, th;
    
    /* logic */
    int quit  = 0;
    int update = 1;
    int px, py;
    float angle = 0;
    
    
    float square[6][2] = {
        {-SQUARE_SIZE, -SQUARE_SIZE},
        { SQUARE_SIZE, -SQUARE_SIZE},
        { SQUARE_SIZE,  SQUARE_SIZE},
        {-SQUARE_SIZE,  SQUARE_SIZE},
    };
    float uv1[6] = {
        0, 0, 
        1, 0,
        1, 1
    };
    float uv2[6] = {
        0, 0, 
        1, 1,
        0, 1
    };
    
    
    float rotated[4][2];
    int coords1[6], coords2[6];
    
    /* Create displayed canvas */
    cv = caca_create_canvas(0, 0);
    if(!cv)
    {
        fprintf(stderr, "%s: unable to initialise libcaca\n", argv[0]);
        return 1;
    }
    
    /* Create texture holding canvas */
    tex = caca_create_canvas(16, 16);
    if(!tex)
    {
        fprintf(stderr, "%s: unable to initialise libcaca\n", argv[0]);
        return 1;
    }
    
    /* Open window */
    dp = caca_create_display(cv);
    if(!dp)
    {
        fprintf(stderr, "%s: unable to initialise libcaca\n", argv[0]);
        return 1;
    }
    
    
    
    /* Set the window title */
    caca_set_display_title(dp, "trifiller");
    
    /* Frame duration */
    caca_set_display_time(dp, 10000);
    
    /* Get displayed canvas size */
    ww = caca_get_canvas_width(cv);
    wh = caca_get_canvas_height(cv);
    
    /* Texture size */
    tw = caca_get_canvas_width(tex);
    th = caca_get_canvas_height(tex);
    
    /* Load texture if any */
    if(argc == 2)
    {
        struct image *im = load_image(argv[1]);
        if(!im)
        {
            fprintf(stderr, "%s: unable to load image '%s'\n", argv[0], argv[1]);
            return 1;
        }
        
        caca_set_dither_algorithm(im->dither,
                                  caca_get_dither_algorithm_list(NULL)[4]);
        caca_dither_bitmap(tex, 
                           0, 0, 
                           tw, th,  
                           im->dither, im->pixels);
        unload_image(im);
    } 
    /* or generate one */
    else 
    {
        
        int i;
        for(i = 0; i < 16; i ++) 
        {
            caca_set_color_ansi(tex, (i+1)%0xF, i%0xF);
            caca_put_str(tex, 0, i, "0123456789ABCDEF");
        }
    }
    

    px = 0;
    py = 0;
    
    while(!quit)
    {
        caca_event_t ev;
        unsigned int const event_mask = CACA_EVENT_KEY_PRESS
        | CACA_EVENT_RESIZE
        | CACA_EVENT_QUIT;
        int event;
        
        if(update)
            event = caca_get_event(dp, event_mask, &ev, 0);
        else
            event = caca_get_event(dp, event_mask, &ev, -1);
        
        while(event)
        {
            if(caca_get_event_type(&ev) & CACA_EVENT_KEY_PRESS)
                switch(caca_get_event_key_ch(&ev)) 
            {
                case 'q':
                case 'Q':
                case CACA_KEY_ESCAPE:
                    quit = 1;
                    break;
                case CACA_KEY_UP:
                    py--;
                    break;
                case CACA_KEY_DOWN:
                    py++;
                    break;
                case CACA_KEY_LEFT:
                    px--;
                    break;
                case CACA_KEY_RIGHT:
                    px++;
                    break;
                case 'a':
                    angle+=1.0f;
                    break;
                case 's':
                    angle-=1.0f;
                    break;                    
            }
            else if(caca_get_event_type(&ev) == CACA_EVENT_RESIZE)
            {
                caca_refresh_display(dp);
                ww = caca_get_event_resize_width(&ev);
                wh = caca_get_event_resize_height(&ev);
                update = 1;
            } 
            else if(caca_get_event_type(&ev) & CACA_EVENT_QUIT)
                quit = 1;
            
            event = caca_get_event(dp, CACA_EVENT_KEY_PRESS, &ev, 0);
        }
        
        
        
        /* 2D Rotation around screen center */
        int p;
        for(p=0; p<4; p++) 
        {
            rotated[p][0] = square[p][0] * cos(angle*M_PI/180.0f) - square[p][1] * sin(angle*M_PI/180.0f);
            rotated[p][1] = square[p][0] * sin(angle*M_PI/180.0f) + square[p][1] * cos(angle*M_PI/180.0f);
            
            rotated[p][0] += ww/2 + px;
            rotated[p][1] += wh/2 + py;
        }
        
        angle+=1.0f;
        
        
        /* Reaarange coordinates to fit libcaca's format */
        coords1[0] = rotated[0][0]; coords1[1] = rotated[0][1];
        coords1[2] = rotated[1][0]; coords1[3] = rotated[1][1];
        coords1[4] = rotated[2][0]; coords1[5] = rotated[2][1];
       
        coords2[0] = rotated[0][0]; coords2[1] = rotated[0][1];
        coords2[2] = rotated[2][0]; coords2[3] = rotated[2][1];
        coords2[4] = rotated[3][0]; coords2[5] = rotated[3][1];
        
        /* Display two triangles */
        caca_fill_triangle_textured(cv,      /* canvas */
                                    coords1, /* triangle coordinates */
                                    tex,     /* texture canvas */
                                    uv1);    /* texture coordinates */
        caca_fill_triangle_textured(cv,
                                    coords2,
                                    tex,
                                    uv2);
        
        /* Refresh display and clear for next frame */
        caca_refresh_display(dp);
        caca_clear_canvas(cv);
        
    }
    
    caca_free_display(dp);
    caca_free_canvas(cv);
    caca_free_canvas(tex);
    
    return 0;
}