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IABSD.fr/xenocara/app/xlockmore/modes/fzort.c

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  • Author : matthieu
    Date : 2006-11-26 11:07:42
    Hash : 110b2a92
    Message : Importing xlockmore 5.22

  • app/xlockmore/modes/fzort.c
  • /* Author: Mauro Persano (mauro_persano@yahoo.com)  27 Nov 2005
     *
     * Todo:
     *   - support for 4-bit / packed 24-bit visuals.
     *
     * Revision history:
     * 06-Dec-2005: fixed stupid off-by-one buf; (preliminar) monochrome support.
     * 05-Dec-2005: more speed ups.
     * 27-Nov-2005: speed ups.
     * 21-Nov-2005: initial version
     */
    #ifdef STANDALONE
    #define MODE_fzort
    #define PROGCLASS "Fzort"
    #define HACK_INIT init_fzort
    #define HACK_DRAW draw_fzort
    #define fzort_opts xlockmode_opts
    #define DEFAULTS "*delay: 0 \n"
    #define UNIFORM_COLORS
    #include "xlockmore.h" /* xscreensaver distribution */
    #else /* STANDALONE */
    #include "xlock.h" /* xlockmore distribution */
    #endif /* STANDALONE */
    
    #ifdef MODE_fzort
    
    #include <sys/types.h>
    #include <sys/ipc.h>
    #include <sys/shm.h>
    #include <sys/time.h>
    #include <X11/Xutil.h>
    #include <X11/extensions/XShm.h>
    
    ModeSpecOpt fzort_opts =
    {0, (XrmOptionDescRec *)NULL, 0, (argtype *)NULL, (OptionStruct *)NULL };
    
    #ifdef USE_MODULES
    ModStruct fzort_description =
    { "fzort", "init_fzort", "draw_fzort", "release_fzort",
      "refresh_fzort", "init_fzort", (char *)NULL, &fzort_opts,
      10000, 1, 1, 1, 64, 1.0, "",
      "Shows a metallic-looking fzort.", 0, NULL };
    #endif
    
    #define MESH_DENSITY 22
    /* #define MESH_DENSITY 44 */
    
    #define MAX_WIDTH 800
    #define MAX_HEIGHT 800
    #define TEXTURE_SIZE 256 /* use a power of 2 preferably */
    
    extern int XShmGetEventBase(Display *);
    
    #define MAX_POLY_VTX 20
    
    struct vector {
    	float x, y, z;
    };
    
    struct matrix {
    	float m11, m12, m13, m14;
    	float m21, m22, m23, m24;
    	float m31, m32, m33, m34;
    };
    
    struct vertex {
    	struct vector p;
    	struct vector normal;
    };
    
    struct pvertex {
    	struct vector p;
    	int x_scr, y_scr;
    	long u_txt, v_txt;
    };
    
    struct polygon {
    	int nvtx;
    	int vtx_index[MAX_POLY_VTX];
    	struct vector normal;
    };
    
    struct mesh {
    	int npoly, nvtx;
    	struct vertex *vtx;
    	struct polygon *poly;
    };
    
    struct box {
    	int x_min, y_min, x_max, y_max;
    };
    
    struct clip_limits {
    	int x_min;
    	int x_max;
    	int y_min;
    	int y_max;
    };
    
    struct raster {
    	int width;
    	int height;
    	int pitch;
    	int bpp;
    	void *bits;
    };
    
    struct render_order {
    	float z;
    	unsigned zi;
    	struct polygon *poly;
    };
    
    typedef struct fzort_ctx {
    	Bool initialized;
    
    	int palette[256];
    	int using_shm;
    
    	XShmSegmentInfo shm_info;
    	XImage *image;
    
    	struct clip_limits clip;
    	struct raster raster;
    	struct mesh *mesh;
    	void *texture;
    
    	/* render ctx */
    	float lx, ly, cx, cy;
    	void(*fill_triangle_fn)(struct fzort_ctx *, struct pvertex *,
    	  struct pvertex *, struct pvertex *);
    	struct pvertex *pvtx;
    	struct render_order *order_in, *order_out;
    
    	long start_ticks;
    
    	struct box cur_box, prev_box;
    	int first_frame;
    } fzort_ctx;
    
    static fzort_ctx *fzorts = (fzort_ctx *) NULL;
    static int shm_completion_event;
    static unsigned char texture8[TEXTURE_SIZE*TEXTURE_SIZE];
    static int texture_initialized = False;
    
    /* ordered dithering matrix */
    
    static unsigned int dither6[8][8] = {
    {     1, 59, 15, 55,  2, 56, 12, 52, },
    {    33, 17, 47, 31, 34, 18, 44, 28, },
    {     9, 49,  5, 63, 10, 50,  6, 60, },
    {    41, 25, 37, 21, 42, 26, 38, 22, },
    {     3, 57, 13, 53,  0, 58, 14, 54, },
    {    35, 19, 45, 29, 32, 16, 46, 30, },
    {    11, 51,  7, 61,  8, 48,  4, 62, },
    {    43, 27, 39, 23, 40, 24, 36, 20 } };
    
    /*
     *	f i x p o i n t
     */
    
    #if defined(__GNUC__) && defined(__i386__)
    #define FP_SHIFT				16
    #else
    #define FP_SHIFT				10
    #endif
    
    #define FP_SHIFT_COMPL		(32 - FP_SHIFT)
    #define FP_MULTIPLIER		(1L << FP_SHIFT)
    #define FP_ONE				(1L << FP_SHIFT)
    #define FP_HALF				(1L << (FP_SHIFT - 1))
    #define INT_TO_FP(a)		((a) << FP_SHIFT)
    #define FP_TO_INT(f)		((f) >> FP_SHIFT)
    #define FLOAT_TO_FP(f)		((long)((f) * (float)FP_MULTIPLIER))
    #define FP_TO_FLOAT(f)		((float)(f) / (float)FP_MULTIPLIER)
    #define FRAC_PART(f)		((f) & (FP_MULTIPLIER - 1))
    #define FP_CEIL(f)			(((f) + FP_MULTIPLIER - 1) & \
    				  			  ~(FP_MULTIPLIER - 1))
    #define FP_FLOOR(f)			((f) & ~(FP_MULTIPLIER - 1))
    #define FP_ICEIL(f)			(((f) + FP_ONE - 1) >> FP_SHIFT)
    #define FP_IFLOOR(f)		((f) >> FP_SHIFT)
    
    /* a / b */
    #if defined(__GNUC__) && defined(__i386__)
    static inline long
    fp_div(long a, long b)
    {
    	long c;
    	asm volatile("movl %%eax,%%edx; shll %3,%%eax; sarl %4,%%edx; idivl %2"
    		: "=a"(c)
    		: "0"(a), "m"(b), "i"(FP_SHIFT), "i"(32 - FP_SHIFT)
    		: "edx");
    	return c;
    }
    #else
    static inline long
    fp_div(long a, long b)
    {
    	return (a << FP_SHIFT)/b;
    }
    #endif
    
    /* a * b */
    #if defined(__GNUC__) && defined(__i386__)
    static inline long
    fp_mul(long a, long b)
    {
    	long c;
        asm volatile("imull %2; shrdl %3,%%edx,%%eax"
    		: "=a"(c)
    		: "0"(a), "m"(b), "i"(FP_SHIFT)
    		: "edx"); 
    	return c;
    }
    #else
    static inline long
    fp_mul(long a, long b)
    {
    	return (a*b) >> FP_SHIFT;
    }
    #endif
    
    /* s + a * b */
    #if defined(__GNUC__) && defined(__i386__)
    static inline long
    fp_mul_add(long s, long a, long b)
    {
    	long c;
        asm volatile("imull %2; shrdl %3,%%edx,%%eax; addl %4,%%eax"
    		: "=a"(c)
    		: "0"(a), "m"(b), "i"(FP_SHIFT), "m"(s)
    		: "edx"); 
    	return c;
    }
    #else
    static inline long
    fp_mul_add(long s, long a, long b)
    {
    	return s + ((a*b) >> FP_SHIFT);
    }
    #endif
    
    
    /*
     *  v e c t o r
     */
    
    static inline void
    vec_copy(struct vector *r, struct vector *a)
    {
    	memcpy(r, a, sizeof *r);
    }
    
    static inline void
    vec_set(struct vector *r, float x, float y, float z)
    {
    	r->x = x;
    	r->y = y;
    	r->z = z;
    }
    
    static inline void
    vec_neg_copy(struct vector *r, struct vector *a)
    {
    	r->x = -a->x;
    	r->y = -a->y;
    	r->z = -a->z;
    }
    
    static inline void
    vec_neg(struct vector *r)
    {
    	vec_neg_copy(r, r);
    }
    
    static inline void
    vec_add(struct vector *r, struct vector *a, struct vector *b)
    {
    	r->x = a->x + b->x;
    	r->y = a->y + b->y;
    	r->z = a->z + b->z;
    }
    
    static inline void
    vec_add_to(struct vector *a, struct vector *b)
    {
    	a->x += b->x;
    	a->y += b->y;
    	a->z += b->z;
    }
    
    static inline void
    vec_sub(struct vector *r, struct vector *a, struct vector *b)
    {
    	r->x = a->x - b->x;
    	r->y = a->y - b->y;
    	r->z = a->z - b->z;
    }
    
    static inline void
    vec_sub_from(struct vector *a, struct vector *b)
    {
    	a->x -= b->x;
    	a->y -= b->y;
    	a->z -= b->z;
    }
    
    static inline float
    vec_dot_product(struct vector *a, struct vector *b)
    {
    	return a->x*b->x + a->y*b->y + a->z*b->z;
    }
    
    static inline float
    vec_length_squared(struct vector *a)
    {
    	return vec_dot_product(a, a);
    }
    
    static inline void
    vec_cross_product(struct vector *r, struct vector *a, struct vector *b)
    {
    	r->x = a->y*b->z - a->z*b->y;
    	r->y = a->z*b->x - a->x*b->z;
    	r->z = a->x*b->y - a->y*b->x;
    }
    
    static inline void
    vec_scalar_mul(struct vector *a, float s)
    {
    	a->x *= s;
    	a->y *= s;
    	a->z *= s;
    }
    
    static inline void
    vec_scalar_mul_copy(struct vector *r, struct vector *a, float s)
    {
    	r->x = a->x*s;
    	r->y = a->y*s;
    	r->z = a->z*s;
    }
    
    static float
    vec_length(struct vector *a)
    {
    	return sqrt(vec_length_squared(a));
    }
    
    static void
    vec_normalize(struct vector *a)
    {
    	float l;
    
    	l = vec_length(a);
    
    	if (l == 0.f)
    		a->x = 1.f, a->y = 0.f, a->z = 0.f;
    	else
    		vec_scalar_mul(a, 1.f/l);
    }
    
    
    /*
     *  m a t r i x
     */
    
    static inline void
    mat_copy(struct matrix *r, struct matrix *m)
    {
    	memcpy(r, m, sizeof *r);
    }
    
    static const struct matrix identity = {
    	1.f, 0.f, 0.f, 0.f,
    	0.f, 1.f, 0.f, 0.f,
    	0.f, 0.f, 1.f, 0.f
    };
    
    static void
    mat_make_identity(struct matrix *m)
    {
    	memcpy(m, &identity, sizeof *m);
    }
    
    static void
    mat_make_rotation_around_x(struct matrix *m, float ang)
    {
    	float c, s;
    
    	c = cos(ang);
    	s = sin(ang);
    
    	mat_make_identity(m);
    
    	m->m22 = c; m->m23 = -s;
    	m->m32 = s; m->m33 = c; 
    }
    
    static void
    mat_make_rotation_around_y(struct matrix *m, float ang)
    {
    	float c, s;
    
    	c = cos(ang);
    	s = sin(ang);
    
    	mat_make_identity(m);
    
    	m->m11 = c; m->m13 = -s;
    	m->m31 = s; m->m33 = c;
    }
    
    #if 0
    static void
    mat_make_rotation_around_z(struct matrix *m, float ang)
    {
    	float c, s;
    
    	c = cos(ang);
    	s = sin(ang);
    
    	mat_make_identity(m);
    
    	m->m11 = c; m->m12 = -s;
    	m->m21 = s; m->m22 = c;
    }
    #endif
    
    static void
    mat_make_translation(struct matrix *m, float x, float y, float z)
    {
    	mat_make_identity(m);
    
    	m->m14 = x;
    	m->m24 = y;
    	m->m34 = z;
    }
    
    static void
    mat_mul_copy(struct matrix *r, struct matrix *a, struct matrix *b)
    {
    	float l11, l12, l13, l14;
    	float l21, l22, l23, l24;
    	float l31, l32, l33, l34;
    
    	l11 = a->m11*b->m11 + a->m12*b->m21 + a->m13*b->m31;
    	l12 = a->m11*b->m12 + a->m12*b->m22 + a->m13*b->m32;
    	l13 = a->m11*b->m13 + a->m12*b->m23 + a->m13*b->m33;
    	l14 = a->m11*b->m14 + a->m12*b->m24 + a->m13*b->m34 + a->m14;
    
    	l21 = a->m21*b->m11 + a->m22*b->m21 + a->m23*b->m31;
    	l22 = a->m21*b->m12 + a->m22*b->m22 + a->m23*b->m32;
    	l23 = a->m21*b->m13 + a->m22*b->m23 + a->m23*b->m33;
    	l24 = a->m21*b->m14 + a->m22*b->m24 + a->m23*b->m34 + a->m24;
    
    	l31 = a->m31*b->m11 + a->m32*b->m21 + a->m33*b->m31;
    	l32 = a->m31*b->m12 + a->m32*b->m22 + a->m33*b->m32;
    	l33 = a->m31*b->m13 + a->m32*b->m23 + a->m33*b->m33;
    	l34 = a->m31*b->m14 + a->m32*b->m24 + a->m33*b->m34 + a->m34;
    
    	r->m11 = l11; r->m12 = l12; r->m13 = l13; r->m14 = l14;
    	r->m21 = l21; r->m22 = l22; r->m23 = l23; r->m24 = l24;
    	r->m31 = l31; r->m32 = l32; r->m33 = l33; r->m34 = l34;
    }
    
    #if 0
    static void
    mat_mul(struct matrix *a, struct matrix *b)
    {
    	mat_mul_copy(a, a, b);
    }
    #endif
    
    static void
    mat_transform_copy(struct vector *r, struct matrix *m,
      struct vector *v)
    {
    	float x, y, z;
    
    	x = m->m11*v->x + m->m12*v->y + m->m13*v->z + m->m14;
    	y = m->m21*v->x + m->m22*v->y + m->m23*v->z + m->m24;
    	z = m->m31*v->x + m->m32*v->y + m->m33*v->z + m->m34;
    
    	r->x = x;
    	r->y = y;
    	r->z = z;
    }
    
    static inline void
    mat_rotate_copy(struct vector *r, struct matrix *m, struct vector *v)
    {
    	float x, y, z;
    
    	x = m->m11*v->x + m->m12*v->y + m->m13*v->z;
    	y = m->m21*v->x + m->m22*v->y + m->m23*v->z;
    	z = m->m31*v->x + m->m32*v->y + m->m33*v->z;
    
    	r->x = x;
    	r->y = y;
    	r->z = z;
    }
    
    static inline void
    mat_rotate(struct vector *v, struct matrix *m)
    {
    	mat_rotate_copy(v, m, v);
    }
    
    
    /*
     *	t r i a n g l e
     */
    
    struct edge {
    	struct pvertex *v0, *v1;
    	int dx, dy;
    	int du, dv;
    	int sy;
    	long sx;
    	long dxdy;
    	int lines;
    	int adjy;
    };
    
    static inline void
    init_edge(fzort_ctx *ctx, struct edge *edge,
      struct pvertex *v0, struct pvertex *v1)
    {
    	float y_max;
    
    	edge->v0 = v0;
    	edge->v1 = v1;
    	edge->dx = v1->x_scr - v0->x_scr;
    	edge->dy = v1->y_scr - v0->y_scr;
    	edge->du = v1->u_txt - v0->u_txt;
    	edge->dv = v1->v_txt - v0->v_txt;
    
    	edge->sy = v0->y_scr;
    	if (edge->sy < ctx->clip.y_min) {
    		edge->adjy = ctx->clip.y_min - edge->sy;
    		edge->sy = ctx->clip.y_min;
    	} else {
    		edge->adjy = 0;
    	}
    
    	y_max = v1->y_scr;
    	if (y_max > ctx->clip.y_max)
    		y_max = ctx->clip.y_max;
    
    	if (y_max <= edge->sy) {
    		edge->lines = 0;
    	} else {
    		edge->lines = (int) (y_max - edge->sy);
    		edge->dxdy = fp_div(edge->dx, edge->dy);
    		edge->sx = INT_TO_FP(v0->x_scr) + edge->adjy*edge->dxdy;
    	} 
    }
    
    #define CONCAT(a, b) a ## b
    
    #define NAME fill_triangle_1bpp_lsb_to_msb
    #define PIXEL_TYPE unsigned char
    #define LSB_TO_MSB
    #define MONOCHROME
    #include "fz_filler.h"
    
    #define NAME fill_triangle_1bpp_msb_to_lsb
    #define PIXEL_TYPE unsigned char
    #define MONOCHROME
    #include "fz_filler.h"
    
    #define NAME fill_triangle_8bpp
    #define PIXEL_TYPE unsigned char
    #include "fz_filler.h"
    
    #define NAME fill_triangle_16bpp
    #define PIXEL_TYPE unsigned short
    #include "fz_filler.h"
    
    #define NAME fill_triangle_32bpp
    #define PIXEL_TYPE unsigned int
    #include "fz_filler.h"
    
    /*
     *	r e n d e r
     */
    
    static void
    radix_sort(struct render_order *out, struct render_order *in, int rshift,
      int n)
    {
    	static int count[256], index[256];
    	int i, b;
    
    	memset(count, 0, sizeof count);
    
    	for (i = 0; i < n; i++) {
    		b = (in[i].zi >> rshift) & 0xff;
    		count[b]++;
    	}
    
    	index[0] = 0;
    
    	for (i = 1; i < 256; i++)
    		index[i] = index[i - 1] + count[i - 1];
    
    	for (i = 0; i < n; i++) {
    		b = (in[i].zi >> rshift) & 0xff;
    		out[index[b]] = in[i];
    		index[b]++;
    	}
    }
    
    static void
    render_process_mesh(fzort_ctx *ctx, struct matrix *m)
    {
    	struct polygon *pin, *pend;
    	struct vertex *v, *vend;
    	struct pvertex *pv;
    	int i, j, npoly, x_scr_min, x_scr_max, y_scr_min, y_scr_max;
    
    	/* vertices */
    
    	ctx->cur_box.x_min = ctx->cur_box.y_min =
    	ctx->cur_box.x_max = ctx->cur_box.y_max = 0;
    
    	x_scr_min = ctx->clip.x_max + 1;
    	x_scr_max = ctx->clip.x_min - 1;
    	y_scr_min = ctx->clip.y_max + 1;
    	y_scr_max = ctx->clip.y_min - 1;
    
    	vend = ctx->mesh->vtx + ctx->mesh->nvtx;
    	pv = ctx->pvtx;
    
    	for (v = ctx->mesh->vtx; v != vend; v++) {
    		struct vector normal;
    		float w;
    		
    		mat_transform_copy(&pv->p, m, &v->p);
    		mat_rotate_copy(&normal, m, &v->normal);
    		vec_normalize(&normal);
    
    		pv->u_txt = FLOAT_TO_FP((TEXTURE_SIZE/2) +
    		  (TEXTURE_SIZE/2)*normal.y + 0.5);
    		pv->v_txt = FLOAT_TO_FP((TEXTURE_SIZE/2) +
    		  (TEXTURE_SIZE/2)*normal.x + 0.5);
    	
    		w = ctx->lx/pv->p.z;
    		pv->x_scr = (int) (ctx->cx + w*pv->p.x + 0.5);
    		pv->y_scr = (int) (ctx->cy + w*pv->p.y + 0.5);
    
    		if (pv->x_scr < x_scr_min)
    			x_scr_min = pv->x_scr; 
    
    		if (pv->x_scr > x_scr_max)
    			x_scr_max = pv->x_scr; 
    
    		if (pv->y_scr < y_scr_min)
    			y_scr_min = pv->y_scr; 
    
    		if (pv->y_scr > y_scr_max)
    			y_scr_max = pv->y_scr; 
    
    		pv++;
    	}
    
    	if (x_scr_min > ctx->clip.x_max)
    		return;
    
    	ctx->cur_box.x_min =
    	  x_scr_min < ctx->clip.x_min ? ctx->clip.x_min : x_scr_min;
    
    	if (x_scr_max < ctx->clip.x_min)
    		return;
    
    	ctx->cur_box.x_max =
    	  x_scr_max > ctx->clip.x_max ? ctx->clip.x_max : x_scr_max;
    
    	if (y_scr_min > ctx->clip.y_max)
    		return;
    
    	ctx->cur_box.y_min =
    	  y_scr_min < ctx->clip.y_min ? ctx->clip.y_min : y_scr_min;
    
    	if (y_scr_max < ctx->clip.y_min)
    		return;
    
    	ctx->cur_box.y_max =
    	  y_scr_max > ctx->clip.y_max ? ctx->clip.y_max : y_scr_max;
    
    	/* polygons */
    
    	npoly = 0;
    	pend = ctx->mesh->poly + ctx->mesh->npoly;
    
    	for (pin = ctx->mesh->poly; pin != pend; pin++) {
    		int nclip_x_min, nclip_x_max, nclip_y_min, nclip_y_max;
    		int *idx, *iend;
    
    		nclip_x_min = nclip_x_max = nclip_y_min = nclip_y_max = 0;
    
    		iend = &pin->vtx_index[pin->nvtx];
    
    		for (idx = &pin->vtx_index[0]; idx != iend; idx++) {
    			pv = &ctx->pvtx[*idx];
    	
    			nclip_x_min += (pv->x_scr < ctx->clip.x_min);
    			nclip_x_max += (pv->x_scr > ctx->clip.x_max);
    			nclip_y_min += (pv->x_scr < ctx->clip.y_min);
    			nclip_y_max += (pv->y_scr > ctx->clip.y_max);
    		}
    	
    		if (nclip_x_min != pin->nvtx && nclip_x_max != pin->nvtx &&
    		  nclip_y_min != pin->nvtx && nclip_y_max != pin->nvtx) {
    			struct pvertex *p0, *p1, *p2, *p3;
    			int ok;
    
    			p0 = &ctx->pvtx[pin->vtx_index[0]];
    			p1 = &ctx->pvtx[pin->vtx_index[1]];
    			p2 = &ctx->pvtx[pin->vtx_index[2]];
    
    			ok = (p2->x_scr - p0->x_scr)*(p1->y_scr - p0->y_scr) -
    			  (p1->x_scr - p0->x_scr)*(p2->y_scr - p0->y_scr) >= 0;
    
    			if (pin->nvtx == 4) {
    				p3 = &ctx->pvtx[pin->vtx_index[3]];
    
    				ok |= (p3->x_scr - p0->x_scr)*(p2->y_scr - p0->y_scr) -
    				  (p2->x_scr - p0->x_scr)*(p3->y_scr - p0->y_scr) >= 0;
    			}
    
    			if (ok) {
    				ctx->order_in[npoly].poly = pin;
    				ctx->order_in[npoly].z = p0->p.z;
    				npoly++;
    			}
    		}
    	}
    
    	/* draw */
    
    	if (npoly) {
    		float z_min, z_max, z_scale, z;
    		struct polygon *poly;
    
    		z_min = z_max = 0.f;
    	
    		for (i = 0; i < npoly; i++) {
    			z = ctx->order_in[i].z;
    	
    			if (i == 0 || z < z_min)
    				z_min = z;
    	
    			if (i == 0 || z > z_max)
    				z_max = z;
    		}
    	
    		z_scale = 255.f/(z_max - z_min);
    	
    		for (i = 0; i < npoly; i++)
    			ctx->order_in[i].zi = (unsigned int) (z_scale*(ctx->order_in[i].z - z_min));
    	
    		radix_sort(ctx->order_out, ctx->order_in, 0, npoly);
    	
    		for (i = npoly - 1; i >= 0; i--) {
    			poly = ctx->order_out[i].poly;
    	
    			for (j = 1; j < poly->nvtx - 1; j++) {
    				ctx->fill_triangle_fn(ctx,
    				  &ctx->pvtx[poly->vtx_index[0]],
    				  &ctx->pvtx[poly->vtx_index[j]],
    				  &ctx->pvtx[poly->vtx_index[j + 1]]);
    			}
    		}
    	}
    }
    
    /*
     *	m e s h
     */
    
    static void
    mesh_free(struct mesh *m)
    {
    	if (m->vtx != NULL)
    		free(m->vtx);
    
    	if (m->poly != NULL)
    		free(m->poly);
    
    	free(m);
    }
    
    static inline float
    radius_offset(float phi, float theta, float phase, float amp)
    {
    	return (amp + 4.*amp*sin(3.*phase + theta))*sin(phase + 5.*phi) + 
    	  (amp + 4.*amp*sin(2.*phase + 2.*phi))*sin(phase + 3.*theta); 
    }
    
    static inline void
    calc_coord(struct vector *v, float radius, float phi, float theta,
      float phase, float amp)
    {
    	float mr, r;
    
    	/* coordinates */
    	r = radius + radius_offset(phi, theta, phase, amp);
    	v->z = -r*cos(phi);
    	mr = r*sin(phi);
    	v->y = -mr*sin(theta);
    	v->x = -mr*cos(theta);
    }
    
    static void
    calc_mesh_vertices(struct mesh *mesh, int density, float radius,
      float phase, float amp)
    {
    	struct vertex *vtx;
    	double phi, theta, dphi, dtheta;
    	int u, v, a, b, c;
    	struct vector v0, v1;
    	float mr, r;
    	float cos_theta, sin_theta, cos_phi, sin_phi;
    	float cos_3theta, sin_3theta;
    	float sin_phase, cos_phase;
    	/*float sin_2phase, cos_2phase;*/
    	float sin_3phase, cos_3phase;
    	float cos_dphi, sin_dphi, cos_dtheta, sin_dtheta, st, ct;
    	float offs;
    	float k0, k1;
    
    	vtx = mesh->vtx;
    
    	/* vertices */
    
    	calc_coord(&vtx->p, radius, 0., M_PI, phase, amp);
    
    	vtx++;
    
    	sin_phase = sin(phase);
    	cos_phase = cos(phase);
    
    	/*sin_2phase = 2.*sin_phase*cos_phase;
    	cos_2phase = 1. - 2.*sin_phase*sin_phase;*/
    
    	sin_3phase = 3.*sin_phase - 4.*sin_phase*sin_phase*sin_phase;
    	cos_3phase = 4.*cos_phase*cos_phase*cos_phase - 3.*cos_phase;
    
    	dtheta = 2.*M_PI/density;
    	dphi = M_PI/(density + 1);
    
    	sin_dphi = sin(dphi);
    	cos_dphi = cos(dphi);
    
    	sin_dtheta = sin(dtheta);
    	cos_dtheta = cos(dtheta);
    
    	cos_phi = cos_dphi;
    	sin_phi = sin_dphi;
    
    	for (phi = dphi, u = 0; u < density; u++, phi += dphi) {
    		/* XXX: work these out */
    		k0 = sin(phase + 5.*phi);
    		k1 = amp + 4.*amp*sin(2.*phase + 2.*phi);
    
    		cos_theta = 1.;
    		sin_theta = 0.;
    
    		for (theta = 0., v = 0; v < density; v++, theta += dtheta) {
    			sin_3theta = 3*sin_theta -
    			  4.*sin_theta*sin_theta*sin_theta;
    			cos_3theta = 4*cos_theta*cos_theta*cos_theta -
    			  3.*cos_theta;
    
    			/*
    				(amp + 4.*amp*sin(3.*phase + theta))*
    				  sin(phase + 5.*phi) + 
    				(amp + 4.*amp*sin(2.*phase + 2.*phi))*
    				  sin(phase + 3.*theta); 
    	  		*/
    
    			offs = (amp + 4.*amp*
    			  (sin_3phase*cos_theta + sin_theta*cos_3phase))*k0 +
    			  k1*(sin_phase*cos_3theta + cos_phase*sin_3theta);
    
    			r = radius + offs;
    
    			vtx->p.z = -r*cos_phi;
    			mr = r*sin_phi;
    			vtx->p.y = -mr*sin_theta;
    			vtx->p.x = -mr*cos_theta;
    			vtx++;
    
    			st = sin_theta*cos_dtheta + cos_theta*sin_dtheta;
    			ct = cos_theta*cos_dtheta - sin_theta*sin_dtheta;
    
    			sin_theta = st;
    			cos_theta = ct;
    		}
    
    		st = sin_phi*cos_dphi + cos_phi*sin_dphi;
    		ct = cos_phi*cos_dphi - sin_phi*sin_dphi;
    
    		sin_phi = st;
    		cos_phi = ct;
    	}
    
    	calc_coord(&vtx->p, radius, M_PI, M_PI, phase, amp);
    
    	/* normals */
    
    	vec_set(&mesh->vtx[0].normal, 0., 0., -1.);
    	vec_set(&mesh->vtx[1 + density*density].normal, 0., 0., 1.);
    
    	for (u = 0; u < density; u++) {
    		for (v = 0; v < density; v++) {
    			a = u*density + v + 1;
    			b = u*density + (v + 1)%density + 1;
    			c = (u + 1)*density + 1;
    			if (u < density - 1)
    				c += v;
    
    			vec_sub(&v0, &mesh->vtx[b].p, &mesh->vtx[a].p);
    			vec_sub(&v1, &mesh->vtx[c].p, &mesh->vtx[a].p);
    			vec_cross_product(&mesh->vtx[a].normal, &v0, &v1);
    		}
    	}
    }
    
    static void
    set_triangle(struct polygon *poly, int a, int b, int c)
    {
    	poly->nvtx = 3;
    	poly->vtx_index[0] = a;
    	poly->vtx_index[1] = b;
    	poly->vtx_index[2] = c;
    }
    
    static void
    set_quad(struct polygon *poly, int a, int b, int c, int d)
    {
    	poly->nvtx = 4;
    	poly->vtx_index[0] = a;
    	poly->vtx_index[1] = b;
    	poly->vtx_index[2] = c;
    	poly->vtx_index[3] = d;
    }
    
    static struct mesh *
    make_sphere(int density)
    {
    	int u, v, a, b, c, d;
    	struct polygon *poly;
    	struct mesh *mesh;
    
    	if ((mesh = (struct mesh *) malloc(sizeof *mesh)) == NULL) {
    		return NULL;
    	}
    
    	mesh->npoly = mesh->nvtx = 0;
    
    	/* vertices */
    
    	mesh->nvtx = 2 + density*density;
    	mesh->vtx = malloc(mesh->nvtx * sizeof *mesh->vtx);
    
    	/* polygons */
    
    	mesh->npoly = (density + 1)*density;
    	poly = mesh->poly = malloc(mesh->npoly * sizeof *mesh->poly);
    
    	for (u = 0; u < density; u++) {
    		for (v = 0; v < density; v++) {
    			a = u*density + v + 1;
    			b = u*density + (v + 1)%density + 1;
    
    			if (u == 0) {
    				set_triangle(poly++, a, 0, b);
    			} else {
    				c = (u - 1)*density + v + 1;
    				d = (u - 1)*density + (v + 1)%density + 1;
    
    				set_quad(poly++, a, c, d, b);
    			}
    		}
    	}
    
    	for (v = 0; v < density; v++) {
    		a = density*density + 1;
    		d = (density - 1)*density + ((v + 1) % density) + 1;
    		c = (density - 1)*density + v + 1;
    
    		set_triangle(poly++, a, c, d);
    	}
    
    	return mesh;
    }
    
    /*
     *	t e x t u r e   g e n e r a t i o n
     */
    
    static int
    getpix(unsigned char *dest, int x, int y)
    {
    	return dest[(y&(TEXTURE_SIZE-1))*TEXTURE_SIZE + (x&(TEXTURE_SIZE - 1))];
    }
    
    static void
    putpix(unsigned char *dest, int x, int y, int v)
    {
    	dest[(y&(TEXTURE_SIZE-1))*TEXTURE_SIZE + (x&(TEXTURE_SIZE-1))] = v;
    }
    
    static int
    randnum(int range)
    {
        return LRAND() % (2*(range + 1)) - range;
    }
    
    static int
    plasmaavg(unsigned char *dest, int x1, int y1, int x2, int y2)
    {
        int average, distance;
    
        average = (getpix(dest, x1, y1) + getpix(dest, x2, y2)) / 2;
        distance = abs(x1 - x2) + abs(y1 - y2);
    
        if (distance > 2)
            distance -= 2;
    
        return average + randnum(distance);
    }
    
    static void
    rplasma(unsigned char *dest, int left, int top, int right, int bottom)
    {
        int x, y;
    
        if (abs(top - bottom) < 2 && abs(right - left) < 2)
            return;
    
        x = left;
        y = (top + bottom) / 2;
        if (!getpix(dest, x, y))
    		putpix(dest, x, y, plasmaavg(dest, left, top, left, bottom));
    
        x = right;
        if (!getpix(dest, x, y))
            putpix(dest, x, y, plasmaavg(dest, right, top, right, bottom));
    
        x = (left + right) / 2;
        y = top;
        if (!getpix(dest, x, y))
    		putpix(dest, x, y, plasmaavg(dest, left, top, right, top));
    
        y = bottom;
        if (!getpix(dest, x, y))
    	putpix(dest, x, y, plasmaavg(dest, left, bottom, right, bottom));
    
        y = (top + bottom) / 2;
        if (!getpix(dest, x, y))
            putpix(dest, x, y, (plasmaavg(dest, x, top, x, bottom) +
    	  plasmaavg(dest, left, y, right, y)) / 2 + randnum(right - left));
    
        rplasma(dest, left, top, x, y);
        rplasma(dest, x, top, right, y);
        rplasma(dest, x, y, right, bottom);
        rplasma(dest, left, y, x, bottom);
    }
    
    static void
    flare(unsigned char *dest)
    {
    	int i, j, r;
    	float a;
    	unsigned s;
    
    	struct vector n, l;
    
    	vec_set(&l, -.4, .4, 1.);
    	vec_normalize(&l);
    
    	for (i = 0; i < TEXTURE_SIZE; i++) {
    		for (j = 0; j < TEXTURE_SIZE; j++) {
    			n.x = j - TEXTURE_SIZE/2;
    			n.y = i - TEXTURE_SIZE/2;
    			n.z = -TEXTURE_SIZE/2;
    
    			vec_normalize(&n);
    
    			a = vec_dot_product(&n, &l);
    			a *= a; a *= a;
    			a *= a; a *= a;
    			a *= a; a *= a;
    
    			r = (int) (a*255);
    			s = (dest[i*TEXTURE_SIZE + j]>>1) + r;
    			s = s > 255 ? 255 : s;
    			dest[i*TEXTURE_SIZE + j] = s;
    		}
    	}
    }
    
    static void *
    init_texture(int *palette, int depth)
    {
    	int i, j;
    	unsigned int v, pixel_size;
    	void *texture;
    
    	switch (depth) {
    		case 1: case 8: pixel_size = sizeof(unsigned char); break;
    		case 16: pixel_size = sizeof(unsigned short); break;
    		case 24: case 32: pixel_size = sizeof(unsigned int); break;
    		default: return NULL; /* ugh */
    	}
    
    	if ((texture = malloc(TEXTURE_SIZE*TEXTURE_SIZE*pixel_size)) == NULL) {
    		return NULL;
    	}
    
    	if (!texture_initialized) {
    		memset(texture8, 0, sizeof texture8);
    		rplasma(texture8, 0, 0, TEXTURE_SIZE, TEXTURE_SIZE);
    		flare(texture8);
    		texture_initialized = True;
    	}
    
    	switch (depth) {
    		case 1:
    			memcpy(texture, texture8, TEXTURE_SIZE*TEXTURE_SIZE);
    			break;
    
    		case 8:
    			for (i = 0; i < TEXTURE_SIZE; i++) {
    				for (j = 0; j < TEXTURE_SIZE; j++) {
    					v = texture8[i*TEXTURE_SIZE + j];
    					((unsigned char *)texture)[i*TEXTURE_SIZE + j] = palette[v];
    				}
    			}
    			break;
    
    		case 16:
    			for (i = 0; i < TEXTURE_SIZE; i++) {
    				for (j = 0; j < TEXTURE_SIZE; j++) {
    					v = texture8[i*TEXTURE_SIZE + j];
    					((unsigned short *)texture)[i*TEXTURE_SIZE + j]
    					  = palette[v];
    				}
    			}
    			break;
    
    		case 24:
    		case 32:
    			for (i = 0; i < TEXTURE_SIZE; i++) {
    				for (j = 0; j < TEXTURE_SIZE; j++) {
    					v = texture8[i*TEXTURE_SIZE + j];
    					((unsigned int *)texture)[i*TEXTURE_SIZE + j] = palette[v];
    				}
    			}
    			break;
    	}
    
    	return texture;
    }
    
    
    /*
     *	x i m a g e
     */
    
    static int caught_x_error;
    
    static int
    x_error_handler(Display *display, XErrorEvent *error)
    {
    	caught_x_error = 1;
    
    	return 0;
    }
    
    static XImage *
    create_xshmimage(ModeInfo *mi, XShmSegmentInfo *si, int width, int height)
    {
    	XImage *img;
    	XErrorHandler prev_handler;
    	int depth, format;
    
    	if (MI_DEPTH(mi) == 1 || MI_NPIXELS(mi) > 2) {
    		depth = MI_DEPTH(mi);
    		format = ZPixmap;
    	} else {
    		depth = 1;
    		format = XYBitmap;
    	}
    
    	XSync(MI_DISPLAY(mi), False);
    	prev_handler = XSetErrorHandler(x_error_handler);
    
    	caught_x_error = 0;
    	img = XShmCreateImage(MI_DISPLAY(mi), MI_VISUAL(mi), depth,
    	  format, NULL, si, width, height);
    
    	if (img == NULL || caught_x_error)
    		goto failed_0;
    
    	if ((si->shmid = shmget(IPC_PRIVATE, img->bytes_per_line*img->height,
    	  IPC_CREAT|0777)) == -1)
    		goto failed_1;
    
    	si->readOnly = False;
    	img->data = si->shmaddr = shmat(si->shmid, 0, 0);
    
    	caught_x_error = 0;
    	if (XShmAttach(MI_DISPLAY(mi), si) == False || caught_x_error)
    		goto failed_2;
    
    	XSetErrorHandler(prev_handler);
    
    	XSync(MI_DISPLAY(mi), False);
    
    	shmctl(si->shmid, IPC_RMID, 0);
    
    	return img;
    
    failed_2:
    	shmdt(si->shmaddr);
    failed_1:
    	XDestroyImage(img);
    	XSync(MI_DISPLAY(mi), False);
    failed_0:
    	XSetErrorHandler(prev_handler);
    	return NULL;
    }
    
    static void
    destroy_xshmimage(ModeInfo *mi, XImage *img, XShmSegmentInfo *si)
    {
    	XErrorHandler prev_handler;
    
    	XSync(MI_DISPLAY(mi), False);
    
    	prev_handler = XSetErrorHandler(x_error_handler);
    	XShmDetach(MI_DISPLAY(mi), si);
    	XSetErrorHandler(prev_handler);
    
    	XDestroyImage(img);
    	XSync(MI_DISPLAY(mi), False);
    
    	shmdt(si->shmaddr);
    
    	XSync(MI_DISPLAY(mi), False);
    }
    
    static XImage *
    create_ximage(ModeInfo *mi, int width, int height)
    {
    	XImage *img;
    	int depth, format;
    
    	if (MI_DEPTH(mi) == 1 || MI_NPIXELS(mi) > 2) {
    		depth = MI_DEPTH(mi);
    		format = ZPixmap;
    	} else {
    		depth = 1;
    		format = XYBitmap;
    	}
    
    	if ((img = XCreateImage(MI_DISPLAY(mi), MI_VISUAL(mi), depth,
    	  format, 0, 0, width, height, 8, 0)) == NULL) {
    		return NULL;
    	}
    
    	if ((img->data = calloc(img->height, img->bytes_per_line)) == NULL) {
    	  	XDestroyImage(img);
    		XSync(MI_DISPLAY(mi), False);
    		return NULL;
    	}
    
    	return img;
    }
    
    static int
    make_image(ModeInfo *mi, struct fzort_ctx *fz)
    {
    	int img_width, img_height;
    	
    	img_width = MIN(MI_WIDTH(mi), MI_HEIGHT(mi));
    
    	if (img_width > MAX_WIDTH)
    		img_width = MAX_WIDTH;
    
    	img_height = img_width;
    
    	if (XShmQueryExtension(MI_DISPLAY(mi))) {
    		fz->image = create_xshmimage(mi, &fz->shm_info, img_width,
    		  img_height);
    		fz->using_shm = fz->image != NULL;
    	}
    
    	if (fz->image == NULL) {
    		if ((fz->image = create_ximage(mi, img_width, img_height)) == NULL) {
    			return -1;
    		}
    	}
    
    	return 0;
    }
    
    static void
    free_image(ModeInfo *mi, struct fzort_ctx *fz)
    {
    		if (fz->using_shm) {
    			destroy_xshmimage(mi, fz->image, &fz->shm_info);
    		} else {
    			free(fz->image->data);
    			fz->image->data = NULL;
    			XDestroyImage(fz->image);
    			XSync(MI_DISPLAY(mi), False);
    		}
    		fz->image = NULL;
    }
    
    
    /*
     *	f z o r t
     */
    
    static void
    release_fzort_ctx(ModeInfo *mi, fzort_ctx *fz)
    {
    	if (fz->initialized) {
    		free(fz->pvtx);
    		free(fz->order_in);
    		free(fz->order_out);
    		free(fz->texture);
    		mesh_free(fz->mesh);
    		free_image(mi, fz);
    		fz->initialized = False;
    	}
    }
    
    static void
    init_color_map(ModeInfo *mi, fzort_ctx *fz, float r, float g, float b,
      float kd, float ks, float n)
    {
    	float red, green, blue, ang;
    	unsigned ib, ig, ir;
    	float ka, kb;
    	int i;
    	XColor xc;
    
    	for (i = 0; i < 256; i++) {
    		ang = (255 - i)*(M_PI/2.)/256.0;
    
    		ka = kd * cos(ang);
    		kb = ks * pow(cos(ang), n);
    
    		red = r*ka + kb;
    		green = g*ka + kb;
    		blue = b*ka + kb;
    
    		ib = (unsigned int) ((blue > 1.0) ? 255 : 255*blue);
    		ig = (unsigned int) ((green > 1.0) ? 255 : 255*green);
    		ir = (unsigned int) ((red > 1.0) ? 255 : 255*red);
    
    		xc.red = ir<<8;
    		xc.green = ig<<8;
    		xc.blue = ib<<8;
    		xc.flags = DoRed|DoGreen|DoBlue;
    
    		XAllocColor(MI_DISPLAY(mi), MI_COLORMAP(mi), &xc);
    
    		fz->palette[i] = xc.pixel;
    	}
    }
    
    static void
    init_fzort_ctx(ModeInfo *mi, fzort_ctx *fz)
    {
    	struct timeval tv;
    
    	if (fz->initialized) {
    		release_fzort_ctx(mi, fz);
    	}
    
    	/* 0. create image for double-buffering */
    
    	if (make_image(mi, fz) < 0) {
    		goto failed_0;
    	}
    
    	fz->clip.x_min = 0;
    	fz->clip.y_min = 0;
    	fz->clip.x_max = fz->image->width - 1;
    	fz->clip.y_max = fz->image->height - 1;
    
    	fz->raster.width = fz->image->width;
    	fz->raster.height = fz->image->height;
    	fz->raster.pitch = fz->image->bytes_per_line;
    	fz->raster.bits = fz->image->data;
    	fz->raster.bpp = fz->image->bits_per_pixel;
    
    	fz->lx = fz->raster.width;
    	fz->ly = fz->raster.height;
    	fz->cx = fz->raster.width/2;
    	fz->cy = fz->raster.height/2;
    
    	switch (fz->raster.bpp) {
    		case 1:
    			/* check if the leftmost pixel is represented by the least
    			 * significant bit or vice-versa  */
    			fz->image->data[0] = 0;
    			XPutPixel(fz->image, 0, 0, 1);
    			if (fz->image->data[0] == 1)
    				fz->fill_triangle_fn = fill_triangle_1bpp_lsb_to_msb;
    			else
    				fz->fill_triangle_fn = fill_triangle_1bpp_msb_to_lsb;
    			break;
    		case 8: fz->fill_triangle_fn = fill_triangle_8bpp; break;
    		case 16: fz->fill_triangle_fn = fill_triangle_16bpp; break;
    		case 24: case 32:
    		  fz->fill_triangle_fn = fill_triangle_32bpp; break;
    	}
    
    	/* 1. create mesh */
    
    	if ((fz->mesh = make_sphere(MESH_DENSITY)) == NULL) {
    		goto failed_1;
    	}
    
    	/* 2. initialize palette */
    
    	if (fz->image->depth >= 8) {
    		init_color_map(mi, fz, .2, .2, 1., .9, .5, 4.);
    	}
    
    	/* 3. create texture */
    
    	if ((fz->texture = init_texture(fz->palette, fz->image->bits_per_pixel))
    	  == NULL) {
    		goto failed_2;
    	}
    
    	/* 4. allocate memory for vertices and polygons */
    
    	if ((fz->pvtx = malloc(fz->mesh->nvtx * sizeof *fz->pvtx)) == NULL) {
    		goto failed_3;
    	}
    
    	if ((fz->order_in = malloc(fz->mesh->npoly * sizeof *fz->order_in))
    	  == NULL) {
    		goto failed_4;
    	}
    
    	if ((fz->order_out = malloc(fz->mesh->npoly * sizeof *fz->order_out))
    	  == NULL) {
    		goto failed_5;
    	}
    
    	gettimeofday(&tv, NULL);
    	fz->start_ticks = tv.tv_sec*1000 + tv.tv_usec/1000;
    
    	fz->prev_box.x_min = 0;
    	fz->prev_box.x_max = fz->clip.x_max;
    	fz->prev_box.y_min = 0;
    	fz->prev_box.y_max = fz->clip.y_max;
    
    	fz->initialized = True;
    
    	MI_CLEARWINDOW(mi);
    
    	return;
    
    failed_5:
    	free(fz->order_in);
    failed_4:
    	free(fz->pvtx);
    failed_3:
    	free(fz->texture);
    failed_2:
    	mesh_free(fz->mesh);
    failed_1:
    	free_image(mi, fz);
    failed_0:
    	return;
    }
    
    static void
    render(fzort_ctx *fz, long ticks)
    {
    	struct matrix t, v;
    	float a, b/* ,c*/;
    	struct matrix rmatrix, ry, rx;
    
    	a = (float)ticks/2000.;
    
    	calc_mesh_vertices(fz->mesh, MESH_DENSITY, 120.,
    	  /* 4.*a, 12. + 5.*sin(2.*a)); */
    	  4.*a, 7. + 7.*sin(2.*a));
    	  /* 0., 0.); */
    
    	b = 1.5*a;
    	/*c = 2.2*a;*/
    
    	mat_make_rotation_around_y(&ry, 1.5*a);
    	mat_make_rotation_around_x(&rx, 2.2*a);
    	mat_mul_copy(&rmatrix, &ry, &rx);
    	mat_make_translation(&t, 220.*sin(b), 220.*cos(a),
    	  900. + 80.*cos(b)*sin(a));
    	mat_mul_copy(&v, &t, &rmatrix);
    	render_process_mesh(fz, &v);
    }
    
    /*
     *   P u b l i c   i n t e r f a c e
     */
    
    void
    init_fzort(ModeInfo *mi)
    {
    	fzort_ctx *fz;
    
    	if (fzorts == NULL) {
    		if ((fzorts = (fzort_ctx *) calloc(MI_NUM_SCREENS(mi),
    		  sizeof (fzort_ctx))) == NULL)
    			return;
    	}
    
    	fz = &fzorts[MI_SCREEN(mi)];
    
    	init_fzort_ctx(mi, fz);
    
    	shm_completion_event = XShmGetEventBase(MI_DISPLAY(mi)) + ShmCompletion;
    }
    
    void
    draw_fzort(ModeInfo *mi)
    {
    	fzort_ctx *fz;
    	int x0, y0, src_x_min, src_y_min, src_x_max, src_y_max;
    	int lines, bytes_per_pixel, bytes_per_block;
    	char *ptr;
    	long cur_ticks;
    	struct timeval tv;
    
    	if (fzorts == NULL)
    		return;
    
    	fz = &fzorts[MI_SCREEN(mi)];
    #if 0
    	printf("Dies after here on Solaris/gcc\n");
    	if (!fz->initialized)
    		return;
    	printf("Dies before here on Solaris/gcc\n");
    #else
    	if (!fz->initialized)
    		return;
    #endif
    
    	/* clear what was used by previous iteration */
    
    	if (fz->image->bits_per_pixel < 8) {
    		/* monochrome pixmaps use so little memory that it's probably cheaper
    		 * to do a single memset  */
    		memset(fz->image->data, 0, fz->image->height*fz->image->bytes_per_line);
    	} else {
    		bytes_per_pixel = fz->image->bits_per_pixel/8;
    		lines = fz->prev_box.y_max - fz->prev_box.y_min + 1;
    		ptr = fz->image->data +
    		  fz->prev_box.y_min*fz->image->bytes_per_line +
    		  fz->prev_box.x_min*bytes_per_pixel;
    		bytes_per_block= (fz->prev_box.x_max - fz->prev_box.x_min + 1)*
    		  bytes_per_pixel;
    
    		while (lines--) {
    			memset(ptr, 0, bytes_per_block);
    			ptr += fz->image->bytes_per_line;
    		}
    	}
    
    	gettimeofday(&tv, NULL);
    	cur_ticks = tv.tv_sec*1000 + tv.tv_usec/1000;
    
    	/* render */
    
    	render(fz, cur_ticks - fz->start_ticks);
    
    	/* display image */
    
    	x0 = (MI_WIDTH(mi) - fz->image->width)/2;
    	y0 = (MI_HEIGHT(mi) - fz->image->height)/2;
    
    	if (fz->image->width <= 200) {
    		src_x_min = src_y_min = 0;
    		src_x_max = fz->image->width - 1;
    		src_y_max = fz->image->height - 1;
    	} else {
    		src_x_min = MIN(fz->prev_box.x_min, fz->cur_box.x_min);
    		src_y_min = MIN(fz->prev_box.y_min, fz->cur_box.y_min);
    
    		src_x_max = MAX(fz->prev_box.x_max, fz->cur_box.x_max);
    		src_y_max = MAX(fz->prev_box.y_max, fz->cur_box.y_max);
    	}
    
    	XSetForeground(MI_DISPLAY(mi), MI_GC(mi), MI_WHITE_PIXEL(mi));
    	XSetBackground(MI_DISPLAY(mi), MI_GC(mi), MI_BLACK_PIXEL(mi));
    
    	if (fz->using_shm) {
    		XEvent event;
    
    		XShmPutImage(MI_DISPLAY(mi), MI_WINDOW(mi), MI_GC(mi),
    		  fz->image,
    		  src_x_min, src_y_min, x0 + src_x_min, y0 + src_y_min,
    		  src_x_max - src_x_min + 1, src_y_max - src_y_min + 1,
    		  1);
    
    		while (XCheckTypedEvent(MI_DISPLAY(mi), shm_completion_event,
    		  &event) == False)
    		        ;
    	} else {
    		XPutImage(MI_DISPLAY(mi), MI_WINDOW(mi), MI_GC(mi),
    		  fz->image, 
    		  src_x_min, src_y_min, x0 + src_x_min, y0 + src_y_min,
    		  src_x_max - src_x_min + 1, src_y_max - src_y_min + 1);
    	}
    
    	fz->prev_box = fz->cur_box;
    }
    
    void
    release_fzort(ModeInfo *mi)
    {
    	int i;
    
    	if (fzorts != NULL) {
    		for (i = 0; i < MI_NUM_SCREENS(mi); i++) {
    			release_fzort_ctx(mi, &fzorts[i]);
    		}
    	}
    
    	free(fzorts);
    
    	fzorts = (fzort_ctx *) NULL;
    }
    
    void
    refresh_fzort(ModeInfo *mi)
    {
    	MI_CLEARWINDOW(mi);
    }
    
    #endif /* MODE_fzort */