gstreamer/gst/smpte/paint.c

/* GStreamer
 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <math.h>
#include <stdlib.h>
#include "paint.h"

void
gst_smpte_paint_vbox (guint32 *dest, gint stride, 
		      gint x0, gint y0, gint c0, 
		      gint x1, gint y1, gint c1)
{
  gint i, j;
  gint width, height;

  width = x1 - x0;
  height = y1 - y0;
  
  g_assert (width > 0);
  g_assert (height > 0);

  dest = dest + y0 * stride + x0;
        
  for (i = 0; i < height; i++) {
    for (j = 0; j < width; j++) {
      dest[j] = (c1 * j + c0 * (width - j)) / width;
    }
    dest += stride;
  }
}

void
gst_smpte_paint_hbox (guint32 *dest, gint stride, 
		      gint x0, gint y0, gint c0, 
		      gint x1, gint y1, gint c1)
{
  gint i, j;
  gint width, height;

  width = x1 - x0;
  height = y1 - y0;
  
  g_assert (width > 0);
  g_assert (height > 0);

  g_print ("vbox: %d %d %d %d %d %d\n", x0, y0, c0, x1, y1, c1);

  dest = dest + y0 * stride + x0;

  for (i = 0; i < height; i++) {
    guint32 value  = (c1 * i + c0 * (height - i)) / height;
    for (j = 0; j < width; j++) {
      dest[j] = value;
    }
    dest += stride;
  }
}

#define STEP_3D_LINE(dxabs,dyabs,dzabs,sdx,sdy,sdz,xr,yr,zr,px,py,pz) 		\
G_STMT_START { 						\
  if (dxabs >= dyabs && dxabs >= dzabs) {		\
    yr += dyabs;					\
    zr += dzabs;					\
    if (yr >= dxabs) {					\
      py += sdy;					\
      yr -= dxabs;					\
    }							\
    if (zr >= dzabs) {					\
      pz += sdz;					\
      zr -= dxabs;					\
    }							\
    px += sdx;						\
  } else if (dyabs >= dxabs && dyabs >= dzabs) {	\
    xr += dxabs;					\
    zr += dzabs;					\
    if (xr >= dyabs) {					\
      px += sdx;					\
      xr -= dyabs;					\
    }							\
    if (zr >= dzabs) {					\
      pz += sdz;					\
      zr -= dyabs;					\
    }							\
    py += sdy;						\
  } else {						\
    yr += dyabs;					\
    xr += dxabs;					\
    if (yr >= dyabs) {					\
      py += sdy;					\
      yr -= dzabs;					\
    }							\
    if (xr >= dyabs) {					\
      px += sdx;					\
      xr -= dzabs;					\
    }							\
    pz += sdz;						\
  }							\
} G_STMT_END

#define SWAP_INT(a,b) 		\
G_STMT_START { 			\
  gint tmp;			\
  tmp = (a);			\
  (a) = (b);			\
  (b) = (tmp);			\
} G_STMT_END

#define SIGN(a) ((a) < 0 ? -1 : 1)

#define PREPARE_3D_LINE(x0,y0,z0,x1,y1,z1,dxabs,dyabs,dzabs,sdx,sdy,sdz,xr,yr,zr,px,py,pz)\
G_STMT_START { 			\
  gint dx, dy, dz;		\
  dx = x1 - x0;			\
  dy = y1 - y0;			\
  dz = z1 - z0;			\
  dxabs = abs (dx);		\
  dyabs = abs (dy);		\
  dzabs = abs (dz);		\
  sdx = SIGN (dx);		\
  sdy = SIGN (dy);		\
  sdz = SIGN (dz);		\
  xr = dxabs >> 1;		\
  yr = dyabs >> 1;		\
  zr = dzabs >> 1;		\
  px = x0;			\
  py = y0;			\
  pz = z0;			\
} G_STMT_END

void
gst_smpte_paint_triangle_linear (guint32 *dest, gint stride,
				 gint x0, gint y0, gint c0,
				 gint x1, gint y1, gint c1, gint x2, gint y2, gint c2)
{
  gint sdxl, sdyl, sdcl, dxlabs, dylabs, dclabs, xrl, yrl, crl, pxl, pyl, pcl;
  gint sdxr, sdyr, sdcr, dxrabs, dyrabs, dcrabs, xrr, yrr, crr, pxr, pyr, pcr;
  gint i, j, k, seg_start, seg_end;

  if (y0 > y1) { SWAP_INT (x0, x1); SWAP_INT (y0, y1); SWAP_INT (c0, c1); }
  if (y0 > y2) { SWAP_INT (x0, x2); SWAP_INT (y0, y2); SWAP_INT (c0, c2); }
  if (y1 > y2) { SWAP_INT (x1, x2); SWAP_INT (y1, y2); SWAP_INT (c1, c2); }
  
  PREPARE_3D_LINE (x0,y0,c0,x2,y2,c2,
		   dxlabs,dylabs,dclabs,
		   sdxl, sdyl,sdcl,
		   xrl,yrl,crl,
		   pxl,pyl,pcl);

  PREPARE_3D_LINE (x0,y0,c0,x1,y1,c1,
		   dxrabs,dyrabs,dcrabs,
		   sdxr, sdyr,sdcr,
		   xrr,yrr,crr,
		   pxr,pyr,pcr);

  dest = dest + stride * y0;
  seg_start = y0;
  seg_end = y1;

  /* do two passes */
  for (k = 0; k < 2; k++) {
    for (i = seg_start; i < seg_end; i++) {
      gint s = pxl, e = pxr, sc = pcl, ec = pcr;
      gint sign = SIGN (e - s);

      e += sign;
      for (j = s; j != e; j+=sign) {
       dest[j] = (ec * (j - s) + sc * (e - j)) / (e - s);
      }

      while (pyr == i) {
        STEP_3D_LINE (dxrabs, dyrabs, dcrabs, sdxr, sdyr, sdcr, 
	              xrr, yrr, crr, pxr, pyr, pcr);
      }
      while (pyl == i) {
        STEP_3D_LINE (dxlabs, dylabs, dclabs, sdxl, sdyl, sdcl, 
	              xrl, yrl, crl, pxl, pyl, pcl);
      }
      dest += stride;
    }

    PREPARE_3D_LINE (x1,y1,c1,x2,y2,c2,
		     dxrabs,dyrabs,dcrabs,
		     sdxr, sdyr,sdcr,
		     xrr,yrr,crr,
		     pxr,pyr,pcr);

    seg_start = y1;
    seg_end = y2;
  }
}

static void 
draw_bresenham_line (guint32 *dest, gint stride, 
		     gint x0, gint y0, 
		     gint x1, gint y1, 
		     guint32 col)
{
  gint dx = abs (x1 - x0);
  gint dy = abs (y1 - y0);
  gint x_incr, y_incr;
  gint i, dpr, dpru, P, indep;

  dest = dest + y0 * stride + x0;

  x_incr = SIGN (x1 - x0);
  y_incr = SIGN (y1 - y0) * stride;
	
  if (dx >= dy)	{           
    dpr = dy << 1;
    i = dx;
    indep = x_incr;
  }
  else {
    dpr = dx << 1;
    i = dy;
    indep = y_incr;
  }

  dpru = dpr - (i << 1);
  P = dpr - i;

  for (; i >= 0; i--) {
    *dest = col;

    if (P > 0) { 
      dest += x_incr;
      dest += y_incr;
      P += dpru;
    } else {
      dest += indep;
      P += dpr;
    }
  }
}

void
gst_smpte_paint_triangle_clock (guint32 *dest, gint stride,
				gint x0, gint y0, gint c0,
				gint x1, gint y1, gint c1, 
				gint x2, gint y2, gint c2)
{
  gint i;
  gint sign;
  gfloat angle, angle_s, angle_e;
  gfloat len1;

  angle_s = 0.0;
  angle_e = acos (((x1-x0) * (x2-x0) + (y1-y0) * (y2-y0))/
		    (sqrt ((x1-x0) * (x1-x0) + (y1-y0) * (y1-y0)) * 
		     sqrt ((x2-x0) * (x2-x0) + (y2-y0) * (y2-y0))));

  len1 = sqrt ((x1-x0) * (x1-x0) + (y1-y0) * (y1-y0));

  if (x1 == x2) {
    sign = SIGN (y2 - y1);

    for (i = y1; i != (y2 + sign); i += sign) {
      if (y1 == i)
	angle = 0;
      else
        angle = acos (((x1-x0) * (x2-x0) + (y1-y0) * (i-y0)) / 
			(len1 * sqrt ((x1-x0) * (x1-x0) + (i-y0) * (i-y0)))) / angle_e;

      draw_bresenham_line (dest, stride,
		    x0, y0, x1, i, 
		    (c2 * angle + c1 * (1.0-angle)));
    }
  }
  else if (y1 == y2) {
    sign = SIGN (x2 - x1);

    for (i = x1; i != (x2 + sign); i += sign) {
      if (x1 == i)
	angle = 0;
      else
        angle = acos (((x1-x0) * (i-x0) + (y1-y0) * (y2-y0)) / 
			(len1 * sqrt ((i-x0) * (i-x0) + (y2-y0) * (y2-y0)))) / angle_e;

      draw_bresenham_line (dest, stride,
		    x0, y0, i, y1, 
		    (c2 * angle + c1 * (1.0-angle)));
    }
  }
}

void
gst_smpte_paint_box_clock (guint32 *dest, gint stride,
			   gint x0, gint y0, gint c0,
			   gint x1, gint y1, gint c1, 
			   gint x2, gint y2, gint c2)
{
  gfloat angle_m, col_m;
  gint xv, yv;

  if (x1 == x0) { 
    xv = x2;
    yv = y1;
  } else if (y1 == y0) {
    xv = x1;
    yv = y2;
  }
  else {
    g_warning ("paint box clock: not supported");
    return;
  }

  angle_m = 2 * acos (((x1-x0) * (xv-x0) + (y1-y0) * (yv-y0))/
		    (sqrt ((x1-x0) * (x1-x0) + (y1-y0) * (y1-y0)) * 
		     sqrt ((xv-x0) * (xv-x0) + (yv-y0) * (yv-y0)))) / M_PI;
    
  col_m = c2 * angle_m + c1 * (1.0-angle_m);

  gst_smpte_paint_triangle_clock (dest, stride,
		                  x0, y0, c0,
		                  x1, y1, c1,
		                  xv, yv, col_m);
  gst_smpte_paint_triangle_clock (dest, stride,
		                  x0, y0, c0,
		                  xv, yv, col_m,
		                  x2, y2, c2);
}