[dosdemo] / src / polytest.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "screen.h"
#include "demo.h"
#include "3dgfx.h"
#include "gfxutil.h"
#include "polyfill.h"   /* just for struct pimage */
#include "cfgopt.h"
#include "mesh.h"
#include "bsptree.h"

static int init(void);
static void destroy(void);
static void start(long trans_time);
static void draw(void);
static void draw_lowres_raster(void);
static void keypress(int key);
static int gen_texture(struct pimage *img, int xsz, int ysz);

static struct screen scr = {
        "polytest",
        init,
        destroy,
        start, 0,
        draw,
        keypress
};

static float cam_theta, cam_phi = 25;
static float cam_dist = 3;
static struct g3d_mesh cube, torus;
static struct bsptree torus_bsp;

static struct pimage tex;

static int use_bsp = 0;

#define LOWRES_SCALE    10
static uint16_t *lowres_pixels;
static int lowres_width, lowres_height;

struct screen *polytest_screen(void)
{
        return &scr;
}

static int init(void)
{
        int i;

        gen_cube_mesh(&cube, 1.0, 0);
        gen_torus_mesh(&torus, 1.0, 0.25, 24, 12);
        /* scale texcoords */
        for(i=0; i<torus.vcount; i++) {
                torus.varr[i].u *= 4.0;
                torus.varr[i].v *= 2.0;
        }

        /*
        init_bsp(&torus_bsp);
        if(bsp_add_mesh(&torus_bsp, &torus) == -1) {
                fprintf(stderr, "failed to construct torus BSP tree\n");
                return -1;
        }
        */

        gen_texture(&tex, 128, 128);

#ifdef DEBUG_POLYFILL
        lowres_width = fb_width / LOWRES_SCALE;
        lowres_height = fb_height / LOWRES_SCALE;
        lowres_pixels = malloc(lowres_width * lowres_height * 2);
        scr.draw = draw_debug;
#endif

        return 0;
}

static void destroy(void)
{
        free(lowres_pixels);
        free(cube.varr);
        free(torus.varr);
        free(torus.iarr);
        /*
        destroy_bsp(&torus_bsp);
        */
}

static void start(long trans_time)
{
        g3d_matrix_mode(G3D_PROJECTION);
        g3d_load_identity();
        g3d_perspective(50.0, 1.3333333, 0.5, 100.0);

        g3d_enable(G3D_CULL_FACE);
        g3d_enable(G3D_LIGHTING);
        g3d_enable(G3D_LIGHT0);

        g3d_polygon_mode(G3D_TEX_GOURAUD);
}

static void update(void)
{
        mouse_orbit_update(&cam_theta, &cam_phi, &cam_dist);
}


static void draw(void)
{
        float vdir[3];
        const float *mat;

        update();

        memset(fb_pixels, 0, fb_width * fb_height * 2);

        g3d_matrix_mode(G3D_MODELVIEW);
        g3d_load_identity();
        g3d_translate(0, 0, -cam_dist);
        if(opt.sball) {
                g3d_mult_matrix(sball_matrix);
        } else {
                g3d_rotate(cam_phi, 1, 0, 0);
                g3d_rotate(cam_theta, 0, 1, 0);
        }

        g3d_light_pos(0, -10, 10, 20);

        g3d_mtl_diffuse(0.4, 0.7, 1.0);
        g3d_set_texture(tex.width, tex.height, tex.pixels);

        if(use_bsp) {
                /* calc world-space view direction */
                mat = g3d_get_matrix(G3D_MODELVIEW, 0);
                /* transform (0, 0, -1) with transpose(mat3x3) */
                vdir[0] = -mat[2];
                vdir[1] = -mat[6];
                vdir[2] = -mat[10];

                draw_bsp(&torus_bsp, vdir[0], vdir[1], vdir[2]);
        } else {
                zsort_mesh(&torus);
                draw_mesh(&torus);
        }

        /*draw_mesh(&cube);*/
        swap_buffers(fb_pixels);
}

static void draw_debug(void)
{
        update();

        memset(lowres_pixels, 0, lowres_width * lowres_height * 2);

        g3d_matrix_mode(G3D_MODELVIEW);
        g3d_load_identity();
        g3d_translate(0, 0, -cam_dist);
        g3d_rotate(cam_phi, 1, 0, 0);
        g3d_rotate(cam_theta, 0, 1, 0);

        g3d_framebuffer(lowres_width, lowres_height, lowres_pixels);
        /*zsort(&torus);*/
        draw_mesh(&cube);

        draw_lowres_raster();


        g3d_framebuffer(fb_width, fb_height, fb_pixels);

        g3d_polygon_mode(G3D_WIRE);
        draw_mesh(&cube);
        g3d_polygon_mode(G3D_FLAT);

        swap_buffers(fb_pixels);
}


static void draw_huge_pixel(uint16_t *dest, int dest_width, uint16_t color)
{
        int i, j;
        uint16_t grid_color = PACK_RGB16(127, 127, 127);

        for(i=0; i<LOWRES_SCALE; i++) {
                for(j=0; j<LOWRES_SCALE; j++) {
                        dest[j] = i == 0 || j == 0 ? grid_color : color;
                }
                dest += dest_width;
        }
}

static void draw_lowres_raster(void)
{
        int i, j;
        uint16_t *sptr = lowres_pixels;
        uint16_t *dptr = fb_pixels;

        for(i=0; i<lowres_height; i++) {
                for(j=0; j<lowres_width; j++) {
                        draw_huge_pixel(dptr, fb_width, *sptr++);
                        dptr += LOWRES_SCALE;
                }
                dptr += fb_width * LOWRES_SCALE - fb_width;
        }
}

static void keypress(int key)
{
        switch(key) {
        case 'b':
                use_bsp = !use_bsp;
                printf("drawing with %s\n", use_bsp ? "BSP tree" : "z-sorting");
                break;
        }
}

static int gen_texture(struct pimage *img, int xsz, int ysz)
{
        int i, j;
        uint16_t *pix;

        if(!(img->pixels = malloc(xsz * ysz * sizeof *pix))) {
                return -1;
        }
        pix = img->pixels;

        for(i=0; i<ysz; i++) {
                for(j=0; j<xsz; j++) {
                        int val = i ^ j;

                        *pix++ = PACK_RGB16(val, val, val);
                }
        }

        img->width = xsz;
        img->height = ysz;
        return 0;
}