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#include <math.h>
#include "odo-distort-funcs.h"
void
cloth_func (OdoTexture *otex,
CoglTextureVertex *vertex,
gfloat width,
gfloat height,
gpointer data)
{
OdoDistortData *d = data;
gfloat cx, cy, rx, turn_angle, height_radius;
guint shade;
/* Rotate the point around the centre of the curl ray to align it with
* the y-axis.
*/
cx = (1.f - d->turn) * width;
cy = (1.f - d->turn) * height;
rx = ((vertex->x - cx) * cos (-d->angle)) -
((vertex->y - cy) * sin (-d->angle)) - d->radius;
/* Calculate the angle as a function of the distance from the curl ray */
turn_angle = ((rx / d->radius) * G_PI_2) - G_PI_2;
/* Add a gradient that makes it look like lighting and hides the switch
* between textures.
*/
shade = (255 * (1.f - d->amplitude)) +
(((sin (turn_angle) * 96) + 159) * d->amplitude);
vertex->color.red = shade;
vertex->color.green = shade;
vertex->color.blue = shade;
/* Make the wave amplitude lower as its distance from the curl ray increases.
* Not really necessary, but looks a little nicer I think.
*/
height_radius = (1 - rx / width) * d->radius;
vertex->z = height_radius * sin (turn_angle) * d->amplitude;
}
void
bowtie_func (OdoTexture *otex,
CoglTextureVertex *vertex,
gfloat width,
gfloat height,
gpointer data)
{
OdoDistortData *d = data;
gfloat cx, cy, rx, ry, turn_angle, height_radius;
guint shade;
cx = d->turn * (width + width/2);
cy = height/2;
rx = ((vertex->x - cx) * cos (0)) -
((vertex->y - cy) * sin (0));
ry = ((vertex->x - cx) * sin (0)) +
((vertex->y - cy) * cos (0));
/* Make angle as a function of distance from the curl ray */
turn_angle = MAX (-G_PI, MIN (0, (rx / (width/4)) * G_PI_2));
/* Add a gradient that makes it look like lighting */
shade = (cos (turn_angle * 2) * 96) + 159;
vertex->color.red = shade;
vertex->color.green = shade;
vertex->color.blue = shade;
/* Calculate the point on a cone (note, a cone, not a right cone) */
height_radius = ry;
/*ClutterFixed height_radius =
clutter_qmulx (clutter_qdivx (ry, height/2), height/2);*/
ry = height_radius * cos (turn_angle);
vertex->x = (rx * cos (0)) - (ry * sin (0)) + cx;
vertex->y = (rx * sin (0)) + (ry * cos (0)) + cy;
vertex->z = height_radius * sin (turn_angle);
}
void
page_turn_func (OdoTexture *otex,
CoglTextureVertex *vertex,
gfloat width,
gfloat height,
gpointer data)
{
OdoDistortData *d = data;
gfloat cx, cy, rx, ry;
gfloat turn_angle;
guint shade;
/* Rotate the point around the centre of the page-curl ray to align it with
* the y-axis.
*/
cx = (1.f - d->turn) * width;
cy = (1.f - d->turn) * height;
rx = ((vertex->x - cx) * cos (-d->angle)) -
((vertex->y - cy) * sin (-d->angle)) - d->radius;
ry = ((vertex->x - cx) * sin (-d->angle)) +
((vertex->y - cy) * cos (-d->angle));
if (rx > -d->radius * 2)
{
/* Calculate the curl angle as a function from the distance of the curl
* ray (i.e. the page crease)
*/
turn_angle = (rx / d->radius * G_PI_2) - G_PI_2;
shade = (sin (turn_angle) * 96) + 159;
/* Add a gradient that makes it look like lighting and hides the switch
* between textures.
*/
vertex->color.red = shade;
vertex->color.green = shade;
vertex->color.blue = shade;
}
if (rx > 0)
{
/* Make the curl radius smaller as more circles are formed (stops
* z-fighting and looks cool)
*/
gfloat small_radius = d->radius - (turn_angle * 2) / G_PI;
/* Calculate a point on a cylinder (maybe make this a cone at some point)
* and rotate it by the specified angle.
*/
rx = (small_radius * cos (turn_angle)) + d->radius;
vertex->x = (rx * cos (d->angle)) - (ry * sin (d->angle)) + cx;
vertex->y = (rx * sin (d->angle)) + (ry * cos (d->angle)) + cy;
vertex->z = (small_radius * sin (turn_angle)) + d->radius;
}
}
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