diff options
Diffstat (limited to 'hacks/glx/romanboy.c')
| -rw-r--r-- | hacks/glx/romanboy.c | 358 |
1 files changed, 242 insertions, 116 deletions
diff --git a/hacks/glx/romanboy.c b/hacks/glx/romanboy.c index e906082..6957556 100644 --- a/hacks/glx/romanboy.c +++ b/hacks/glx/romanboy.c @@ -3,10 +3,10 @@ smoothly between the Roman surface and the Boy surface. */ #if 0 -static const char sccsid[] = "@(#)romanboy.c 1.1 14/10/03 xlockmore"; +static const char sccsid[] = "@(#)romanboy.c 1.1 03/10/14 xlockmore"; #endif -/* Copyright (c) 2013-2014 Carsten Steger <carsten@mirsanmir.org>. */ +/* Copyright (c) 2014-2020 Carsten Steger <carsten@mirsanmir.org>. */ /* * Permission to use, copy, modify, and distribute this software and its @@ -22,15 +22,16 @@ static const char sccsid[] = "@(#)romanboy.c 1.1 14/10/03 xlockmore"; * other special, indirect and consequential damages. * * REVISION HISTORY: - * C. Steger - 14/10/03: Initial version + * C. Steger - 03/10/14: Initial version + * C. Steger - 06/01/20: Added the changing colors mode. */ /* - * This program shows a 3d immersion of the real projective plane - * that smoothly deforms between the Roman surface and the Boy - * surface. You can walk on the projective plane or turn in 3d. The - * smooth deformation (homotopy) between these two famous immersions - * of the real projective plane was constructed by François Apéry. + * This program shows a 3d immersion of the real projective plane that + * smoothly deforms between the Roman surface and the Boy surface. + * You can walk on the projective plane or turn in 3d. The smooth + * deformation (homotopy) between these two famous immersions of the + * real projective plane was constructed by François Apéry. * * The real projective plane is a non-orientable surface. To make * this apparent, the two-sided color mode can be used. @@ -43,10 +44,11 @@ static const char sccsid[] = "@(#)romanboy.c 1.1 14/10/03 xlockmore"; * The real projective plane is a model for the projective geometry in * 2d space. One point can be singled out as the origin. A line can * be singled out as the line at infinity, i.e., a line that lies at - * an infinite distance to the origin. The line at infinity is - * topologically a circle. Points on the line at infinity are also - * used to model directions in projective geometry. The origin can be - * visualized in different manners. When using distance colors, the + * an infinite distance to the origin. The line at infinity, like all + * lines in the projective plane, is topologically a circle. Points + * on the line at infinity are also used to model directions in + * projective geometry. The origin can be visualized in different + * manners. When using distance colors (and using static colors), the * origin is the point that is displayed as fully saturated red, which * is easier to see as the center of the reddish area on the * projective plane. Alternatively, when using distance bands, the @@ -56,14 +58,15 @@ static const char sccsid[] = "@(#)romanboy.c 1.1 14/10/03 xlockmore"; * markers are being displayed, the origin the the point where all * orientation markers are compressed to a point. The line at * infinity can also be visualized in different ways. When using - * distance colors, the line at infinity is the line that is displayed - * as fully saturated magenta. When two-sided colors are used, the - * line at infinity lies at the points where the red and green "sides" - * of the projective plane meet (of course, the real projective plane - * only has one side, so this is a design choice of the - * visualization). Alternatively, when orientation markers are being - * displayed, the line at infinity is the place where the orientation - * markers change their orientation. + * distance colors (and using static colors), the line at infinity is + * the line that is displayed as fully saturated magenta. When + * two-sided (and static) colors are used, the line at infinity lies + * at the points where the red and green "sides" of the projective + * plane meet (of course, the real projective plane only has one side, + * so this is a design choice of the visualization). Alternatively, + * when orientation markers are being displayed, the line at infinity + * is the place where the orientation markers change their + * orientation. * * Note that when the projective plane is displayed with bands, the * orientation markers are placed in the middle of the bands. For @@ -100,24 +103,28 @@ static const char sccsid[] = "@(#)romanboy.c 1.1 14/10/03 xlockmore"; * projective plane is non-orientable. * * Finally, the colors with with the projective plane is drawn can be - * set to two-sided, distance, or direction. In two-sided mode, the - * projective plane is drawn with red on one "side" and green on the - * "other side". As described above, the projective plane only has - * one side, so the color jumps from red to green along the line at - * infinity. This mode enables you to see that the projective plane - * is non-orientable. In distance mode, the projective plane is - * displayed with fully saturated colors that depend on the distance - * of the points on the projective plane to the origin. The origin is - * displayed in red, the line at infinity is displayed in magenta. If - * the projective plane is displayed as distance bands, each band will - * be displayed with a different color. In direction mode, the - * projective plane is displayed with fully saturated colors that - * depend on the angle of the points on the projective plane with - * respect to the origin. Angles in opposite directions to the origin - * (e.g., 15 and 205 degrees) are displayed in the same color since - * they are projectively equivalent. If the projective plane is - * displayed as direction bands, each band will be displayed with a - * different color. + * set to one-sided, two-sided, distance, or direction. In one-sided + * mode, the projective plane is drawn with the same color on both + * "sides." In two-sided mode (using static colors), the projective + * plane is drawn with red on one "side" and green on the "other + * side." As described above, the projective plane only has one side, + * so the color jumps from red to green along the line at infinity. + * This mode enables you to see that the projective plane is + * non-orientable. If changing colors are used in two-sided mode, + * changing complementary colors are used on the respective "sides." + * In distance mode, the projective plane is displayed with fully + * saturated colors that depend on the distance of the points on the + * projective plane to the origin. If static colors are used, the + * origin is displayed in red, while the line at infinity is displayed + * in magenta. If the projective plane is displayed as distance + * bands, each band will be displayed with a different color. In + * direction mode, the projective plane is displayed with fully + * saturated colors that depend on the angle of the points on the + * projective plane with respect to the origin. Angles in opposite + * directions to the origin (e.g., 15 and 205 degrees) are displayed + * in the same color since they are projectively equivalent. If the + * projective plane is displayed as direction bands, each band will be + * displayed with a different color. * * The rotation speed for each of the three coordinate axes around * which the projective plane rotates can be chosen. @@ -172,10 +179,11 @@ static const char sccsid[] = "@(#)romanboy.c 1.1 14/10/03 xlockmore"; #define APPEARANCE_DIRECTION_BANDS 2 #define NUM_APPEARANCES 3 -#define COLORS_TWOSIDED 0 -#define COLORS_DISTANCE 1 -#define COLORS_DIRECTION 2 -#define NUM_COLORS 3 +#define COLORS_ONESIDED 0 +#define COLORS_TWOSIDED 1 +#define COLORS_DISTANCE 2 +#define COLORS_DIRECTION 3 +#define NUM_COLORS 4 #define VIEW_WALK 0 #define VIEW_TURN 1 @@ -190,6 +198,7 @@ static const char sccsid[] = "@(#)romanboy.c 1.1 14/10/03 xlockmore"; #define DEF_COLORS "random" #define DEF_VIEW_MODE "random" #define DEF_MARKS "False" +#define DEF_CHANGE_COLORS "False" #define DEF_DEFORM "True" #define DEF_PROJECTION "random" #define DEF_SPEEDX "1.1" @@ -239,6 +248,7 @@ static char *color_mode; static char *view_mode; static Bool marks; static Bool deform; +static Bool change_colors; static char *proj; static float speed_x; static float speed_y; @@ -261,16 +271,19 @@ static XrmOptionDescRec opts[] = {"-distance-bands", ".appearance", XrmoptionNoArg, "distance-bands" }, {"-direction-bands", ".appearance", XrmoptionNoArg, "direction-bands" }, {"-colors", ".colors", XrmoptionSepArg, 0 }, + {"-onesided-colors", ".colors", XrmoptionNoArg, "one-sided" }, {"-twosided-colors", ".colors", XrmoptionNoArg, "two-sided" }, {"-distance-colors", ".colors", XrmoptionNoArg, "distance" }, {"-direction-colors", ".colors", XrmoptionNoArg, "direction" }, + {"-change-colors", ".changeColors", XrmoptionNoArg, "on"}, + {"+change-colors", ".changeColors", XrmoptionNoArg, "off"}, {"-view-mode", ".viewMode", XrmoptionSepArg, 0 }, {"-walk", ".viewMode", XrmoptionNoArg, "walk" }, {"-turn", ".viewMode", XrmoptionNoArg, "turn" }, - {"-deform", ".deform", XrmoptionNoArg, "on"}, - {"+deform", ".deform", XrmoptionNoArg, "off"}, - {"-orientation-marks", ".marks", XrmoptionNoArg, "on"}, - {"+orientation-marks", ".marks", XrmoptionNoArg, "off"}, + {"-deform", ".deform", XrmoptionNoArg, "on"}, + {"+deform", ".deform", XrmoptionNoArg, "off"}, + {"-orientation-marks", ".marks", XrmoptionNoArg, "on"}, + {"+orientation-marks", ".marks", XrmoptionNoArg, "off"}, {"-projection", ".projection", XrmoptionSepArg, 0 }, {"-perspective", ".projection", XrmoptionNoArg, "perspective" }, {"-orthographic", ".projection", XrmoptionNoArg, "orthographic" }, @@ -291,6 +304,7 @@ static argtype vars[] = { &mode, "displayMode", "DisplayMode", DEF_DISPLAY_MODE, t_String }, { &appear, "appearance", "Appearance", DEF_APPEARANCE, t_String }, { &color_mode, "colors", "Colors", DEF_COLORS, t_String }, + { &change_colors, "changeColors", "ChangeColors", DEF_CHANGE_COLORS, t_Bool }, { &view_mode, "viewMode", "ViewMode", DEF_VIEW_MODE, t_String }, { &deform, "deform", "Deform", DEF_DEFORM, t_Bool }, { &marks, "marks", "Marks", DEF_MARKS, t_Bool }, @@ -312,6 +326,11 @@ ENTRYPOINT ModeSpecOpt romanboy_opts = /* Offset by which we walk above the projective plane */ #define DELTAY 0.01 +/* Color change speeds */ +#define DRHO 0.7 +#define DSIGMA 1.1 +#define DTAU 1.7 + /* Number of subdivisions of the projective plane */ #define NUMU 64 #define NUMV 128 @@ -327,11 +346,14 @@ typedef struct { int display_mode; int appearance; int colors; + Bool change_colors; int view; int projection; Bool marks; /* 3D rotation angles */ float alpha, beta, delta; + /* Color rotation angles */ + float rho, sigma, tau; /* Movement parameters */ float umove, vmove, dumove, dvmove; int side, dir; @@ -472,54 +494,80 @@ static void quat_to_rotmat(float p[4], float m[3][3]) /* Compute a fully saturated and bright color based on an angle. */ -static void color(romanboystruct *pp, double angle, float col[4]) +static void color(romanboystruct *pp, double angle, float mat[3][3], + float col[4]) { int s; - double t; + double t, ca, sa; + float m; - if (pp->colors == COLORS_TWOSIDED) - return; + if (!pp->change_colors) + { + if (pp->colors == COLORS_ONESIDED || pp->colors == COLORS_TWOSIDED) + return; - if (angle >= 0.0) - angle = fmod(angle,2.0*M_PI); - else - angle = fmod(angle,-2.0*M_PI); - s = floor(angle/(M_PI/3)); - t = angle/(M_PI/3)-s; - if (s >= 6) - s = 0; - switch (s) + if (angle >= 0.0) + angle = fmod(angle,2.0*M_PI); + else + angle = fmod(angle,-2.0*M_PI); + s = floor(angle/(M_PI/3)); + t = angle/(M_PI/3)-s; + if (s >= 6) + s = 0; + switch (s) + { + case 0: + col[0] = 1.0; + col[1] = t; + col[2] = 0.0; + break; + case 1: + col[0] = 1.0-t; + col[1] = 1.0; + col[2] = 0.0; + break; + case 2: + col[0] = 0.0; + col[1] = 1.0; + col[2] = t; + break; + case 3: + col[0] = 0.0; + col[1] = 1.0-t; + col[2] = 1.0; + break; + case 4: + col[0] = t; + col[1] = 0.0; + col[2] = 1.0; + break; + case 5: + col[0] = 1.0; + col[1] = 0.0; + col[2] = 1.0-t; + break; + } + } + else /* pp->change_colors */ { - case 0: - col[0] = 1.0; - col[1] = t; - col[2] = 0.0; - break; - case 1: - col[0] = 1.0-t; - col[1] = 1.0; - col[2] = 0.0; - break; - case 2: - col[0] = 0.0; - col[1] = 1.0; - col[2] = t; - break; - case 3: - col[0] = 0.0; - col[1] = 1.0-t; - col[2] = 1.0; - break; - case 4: - col[0] = t; - col[1] = 0.0; - col[2] = 1.0; - break; - case 5: - col[0] = 1.0; - col[1] = 0.0; - col[2] = 1.0-t; - break; + if (pp->colors == COLORS_ONESIDED || pp->colors == COLORS_TWOSIDED) + { + col[0] = mat[0][2]; + col[1] = mat[1][2]; + col[2] = mat[2][2]; + } + else + { + ca = cos(angle); + sa = sin(angle); + col[0] = ca*mat[0][0]+sa*mat[0][1]; + col[1] = ca*mat[1][0]+sa*mat[1][1]; + col[2] = ca*mat[2][0]+sa*mat[2][1]; + } + m = 0.5f/fmaxf(fmaxf(fabsf(col[0]),fabsf(col[1])),fabsf(col[2])); + col[0] = m*col[0]+0.5f; + col[1] = m*col[1]+0.5f; + col[2] = m*col[2]+0.5f; } if (pp->display_mode == DISP_TRANSPARENT) col[3] = 0.7; @@ -550,10 +598,13 @@ static void setup_roman_boy_color_texture(ModeInfo *mi, double umin, else u = ur*j/numu+umin; v = vr*i/numv+vmin; - if (pp->colors == COLORS_DIRECTION) - color(pp,2.0*M_PI-fmod(2.0*u,2.0*M_PI),&pp->col[4*k]); - else /* pp->colors == COLORS_DISTANCE */ - color(pp,v*(5.0/6.0),&pp->col[4*k]); + if (!pp->change_colors) + { + if (pp->colors == COLORS_DIRECTION) + color(pp,2.0*M_PI-fmod(2.0*u,2.0*M_PI),NULL,&pp->col[4*k]); + else /* pp->colors == COLORS_DISTANCE */ + color(pp,v*(5.0/6.0),NULL,&pp->col[4*k]); + } pp->tex[2*k+0] = -16*g*u/(2.0*M_PI); if (pp->appearance == APPEARANCE_DISTANCE_BANDS) pp->tex[2*k+1] = 32*v/(2.0*M_PI)-0.5; @@ -569,11 +620,14 @@ static int roman_boy(ModeInfo *mi, double umin, double umax, double vmin, double vmax, int numu, int numv) { int polys = 0; - static const GLfloat mat_diff_red[] = { 1.0, 0.0, 0.0, 1.0 }; - static const GLfloat mat_diff_green[] = { 0.0, 1.0, 0.0, 1.0 }; - static const GLfloat mat_diff_trans_red[] = { 1.0, 0.0, 0.0, 0.7 }; - static const GLfloat mat_diff_trans_green[] = { 0.0, 1.0, 0.0, 0.7 }; - float p[3], pu[3], pv[3], pm[3], n[3], b[3], mat[3][3]; + static const GLfloat mat_diff_red[] = { 1.0, 0.0, 0.0, 1.0 }; + static const GLfloat mat_diff_green[] = { 0.0, 1.0, 0.0, 1.0 }; + static const GLfloat mat_diff_oneside[] = { 0.9, 0.4, 0.3, 1.0 }; + static const GLfloat mat_diff_trans_red[] = { 1.0, 0.0, 0.0, 0.7 }; + static const GLfloat mat_diff_trans_green[] = { 0.0, 1.0, 0.0, 0.7 }; + static const GLfloat mat_diff_trans_oneside[] = { 0.9, 0.4, 0.3, 0.7 }; + float mat_diff_dyn[4], mat_diff_dyn_compl[4]; + float p[3], pu[3], pv[3], pm[3], n[3], b[3], mat[3][3], matc[3][3]; int i, j, k, l, m, o, g; double u, v, ur, vr, oz; double xx[3], xxu[3], xxv[3]; @@ -591,6 +645,10 @@ static int roman_boy(ModeInfo *mi, double umin, double umax, r = 1.0+d*d*(1.0/2.0+d*d*(1.0/6.0+d*d*(1.0/3.0))); radius = 1.0/r; oz = 0.5*r; + + if (pp->change_colors) + rotateall(pp->rho,pp->sigma,pp->tau,matc); + if (pp->view == VIEW_WALK) { u = pp->umove; @@ -740,18 +798,54 @@ static int roman_boy(ModeInfo *mi, double umin, double umax, mult_rotmat(r2,r1,mat); } - if (pp->colors == COLORS_TWOSIDED) + if (!pp->change_colors) { - glColor3fv(mat_diff_red); - if (pp->display_mode == DISP_TRANSPARENT) + if (pp->colors == COLORS_ONESIDED) { - glMaterialfv(GL_FRONT,GL_AMBIENT_AND_DIFFUSE,mat_diff_trans_red); - glMaterialfv(GL_BACK,GL_AMBIENT_AND_DIFFUSE,mat_diff_trans_green); + glColor3fv(mat_diff_oneside); + if (pp->display_mode == DISP_TRANSPARENT) + { + glMaterialfv(GL_FRONT_AND_BACK,GL_AMBIENT_AND_DIFFUSE, + mat_diff_trans_oneside); + } + else + { + glMaterialfv(GL_FRONT_AND_BACK,GL_AMBIENT_AND_DIFFUSE, + mat_diff_oneside); + } } - else + else if (pp->colors == COLORS_TWOSIDED) { - glMaterialfv(GL_FRONT,GL_AMBIENT_AND_DIFFUSE,mat_diff_red); - glMaterialfv(GL_BACK,GL_AMBIENT_AND_DIFFUSE,mat_diff_green); + glColor3fv(mat_diff_red); + if (pp->display_mode == DISP_TRANSPARENT) + { + glMaterialfv(GL_FRONT,GL_AMBIENT_AND_DIFFUSE,mat_diff_trans_red); + glMaterialfv(GL_BACK,GL_AMBIENT_AND_DIFFUSE,mat_diff_trans_green); + } + else + { + glMaterialfv(GL_FRONT,GL_AMBIENT_AND_DIFFUSE,mat_diff_red); + glMaterialfv(GL_BACK,GL_AMBIENT_AND_DIFFUSE,mat_diff_green); + } + } + } + else /* pp->change_colors */ + { + color(pp,0.0,matc,mat_diff_dyn); + if (pp->colors == COLORS_ONESIDED) + { + glColor3fv(mat_diff_dyn); + glMaterialfv(GL_FRONT_AND_BACK,GL_AMBIENT_AND_DIFFUSE,mat_diff_dyn); + } + else if (pp->colors == COLORS_TWOSIDED) + { + mat_diff_dyn_compl[0] = 1.0f-mat_diff_dyn[0]; + mat_diff_dyn_compl[1] = 1.0f-mat_diff_dyn[1]; + mat_diff_dyn_compl[2] = 1.0f-mat_diff_dyn[2]; + mat_diff_dyn_compl[3] = mat_diff_dyn[3]; + glColor3fv(mat_diff_dyn); + glMaterialfv(GL_FRONT,GL_AMBIENT_AND_DIFFUSE,mat_diff_dyn); + glMaterialfv(GL_BACK,GL_AMBIENT_AND_DIFFUSE,mat_diff_dyn_compl); } } glBindTexture(GL_TEXTURE_2D,pp->tex_name); @@ -772,6 +866,14 @@ static int roman_boy(ModeInfo *mi, double umin, double umax, o = i*(numu+1)+j; u = ur*j/numu+umin; v = vr*i/numv+vmin; + if (pp->change_colors) + { + /* Compute the colors dynamically. */ + if (pp->colors == COLORS_DIRECTION) + color(pp,2.0*M_PI-fmod(2.0*u,2.0*M_PI),matc,&pp->col[4*o]); + else if (pp->colors == COLORS_DISTANCE) + color(pp,v*(5.0/6.0),matc,&pp->col[4*o]); + } if (g & 1) v = 0.5*M_PI-0.25*v; else @@ -872,6 +974,14 @@ static int roman_boy(ModeInfo *mi, double umin, double umax, o = i*(numu+1)+j; u = -ur*j/numu+umin; v = vr*i/numv+vmin; + if (pp->change_colors) + { + /* Compute the colors dynamically. */ + if (pp->colors == COLORS_DIRECTION) + color(pp,2.0*M_PI-fmod(2.0*u,2.0*M_PI),matc,&pp->col[4*o]); + else if (pp->colors == COLORS_DISTANCE) + color(pp,v*(5.0/6.0),matc,&pp->col[4*o]); + } if (g & 1) v = 0.5*M_PI-0.25*v; else @@ -981,7 +1091,7 @@ static int roman_boy(ModeInfo *mi, double umin, double umax, m = j; o = l*(numu+1)+m; glTexCoord2fv(&pp->tex[2*o]); - if (pp->colors != COLORS_TWOSIDED) + if (pp->colors != COLORS_ONESIDED && pp->colors != COLORS_TWOSIDED) { glColor3fv(&pp->col[4*o]); glMaterialfv(GL_FRONT_AND_BACK,GL_AMBIENT_AND_DIFFUSE, @@ -1013,7 +1123,7 @@ static int roman_boy(ModeInfo *mi, double umin, double umax, m = (j+k); o = l*(numu+1)+m; glTexCoord2fv(&pp->tex[2*o]); - if (pp->colors != COLORS_TWOSIDED) + if (pp->colors != COLORS_ONESIDED && pp->colors != COLORS_TWOSIDED) { glColor3fv(&pp->col[4*o]); glMaterialfv(GL_FRONT_AND_BACK,GL_AMBIENT_AND_DIFFUSE, @@ -1046,7 +1156,7 @@ static void gen_texture(ModeInfo *mi) glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR); glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR); glTexEnvf(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_MODULATE); - glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,TEX_DIMENSION,TEX_DIMENSION,0, + glTexImage2D(GL_TEXTURE_2D,0,GL_LUMINANCE,TEX_DIMENSION,TEX_DIMENSION,0, GL_LUMINANCE,GL_UNSIGNED_BYTE,texture); } @@ -1096,6 +1206,10 @@ static void init(ModeInfo *mi) pp->dd = init_deform*0.001; pp->defdir = -1; + pp->rho = frand(360.0); + pp->sigma = frand(360.0); + pp->tau = frand(360.0); + pp->offset3d[0] = 0.0; pp->offset3d[1] = 0.0; pp->offset3d[2] = -1.8; @@ -1241,6 +1355,18 @@ static void display_romanboy(ModeInfo *mi) if (pp->umove < 0.0) pp->umove += 2.0*M_PI; } + if (pp->change_colors) + { + pp->rho += DRHO; + if (pp->rho >= 360.0) + pp->rho -= 360.0; + pp->sigma += DSIGMA; + if (pp->sigma >= 360.0) + pp->sigma -= 360.0; + pp->tau += DTAU; + if (pp->tau >= 360.0) + pp->tau -= 360.0; + } } glMatrixMode(GL_PROJECTION); @@ -1269,16 +1395,10 @@ static void display_romanboy(ModeInfo *mi) ENTRYPOINT void reshape_romanboy(ModeInfo *mi, int width, int height) { romanboystruct *pp = &romanboy[MI_SCREEN(mi)]; - int y = 0; - - if (width > height * 5) { /* tiny window: show middle */ - height = width; - y = -height/2; - } pp->WindW = (GLint)width; pp->WindH = (GLint)height; - glViewport(0,y,width,height); + glViewport(0,0,width,height); pp->aspect = (GLfloat)width/(GLfloat)height; } @@ -1402,6 +1522,10 @@ ENTRYPOINT void init_romanboy(ModeInfo *mi) { pp->colors = random() % NUM_COLORS; } + else if (!strcasecmp(color_mode,"one-sided")) + { + pp->colors = COLORS_ONESIDED; + } else if (!strcasecmp(color_mode,"two-sided")) { pp->colors = COLORS_TWOSIDED; @@ -1419,6 +1543,8 @@ ENTRYPOINT void init_romanboy(ModeInfo *mi) pp->colors = random() % NUM_COLORS; } + pp->change_colors = change_colors; + /* Set the view mode. */ if (!strcasecmp(view_mode,"random")) { |