1255 lines
35 KiB
C
1255 lines
35 KiB
C
/*****************/
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/* Shading stuff */
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/*****************/
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#include "config.h"
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#include <string.h>
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#include <libpika/pika.h>
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#include <libpika/pikaui.h>
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#include "map-object-apply.h"
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#include "map-object-main.h"
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#include "map-object-image.h"
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#include "map-object-shade.h"
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static gdouble bx1, by1, bx2, by2;
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get_ray_color_func get_ray_color;
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typedef struct
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{
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gdouble u, v;
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gdouble t;
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PikaVector3 s;
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PikaVector3 n;
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gint face;
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} FaceIntersectInfo;
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/*****************/
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/* Phong shading */
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/*****************/
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static PikaRGB
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phong_shade (PikaVector3 *pos,
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PikaVector3 *viewpoint,
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PikaVector3 *normal,
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PikaRGB *diff_col,
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PikaRGB *spec_col,
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LightType type)
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{
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PikaRGB ambientcolor, diffusecolor, specularcolor;
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gdouble NL, RV, dist;
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PikaVector3 L, NN, V, N;
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PikaVector3 *light;
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light = mapvals.lightsource.type == DIRECTIONAL_LIGHT
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? &mapvals.lightsource.direction
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: &mapvals.lightsource.position,
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/* Compute ambient intensity */
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/* ========================= */
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N = *normal;
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ambientcolor = *diff_col;
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pika_rgb_multiply (&ambientcolor, mapvals.material.ambient_int);
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/* Compute (N*L) term of Phong's equation */
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/* ====================================== */
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if (type == POINT_LIGHT)
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pika_vector3_sub (&L, light, pos);
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else
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L = *light;
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dist = pika_vector3_length (&L);
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if (dist != 0.0)
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pika_vector3_mul (&L, 1.0 / dist);
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NL = 2.0 * pika_vector3_inner_product (&N, &L);
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if (NL >= 0.0)
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{
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/* Compute (R*V)^alpha term of Phong's equation */
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/* ============================================ */
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pika_vector3_sub (&V, viewpoint, pos);
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pika_vector3_normalize (&V);
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pika_vector3_mul (&N, NL);
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pika_vector3_sub (&NN, &N, &L);
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RV = pika_vector3_inner_product (&NN, &V);
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RV = 0.0 < RV ? pow (RV, mapvals.material.highlight) : 0.0;
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/* Compute diffuse and specular intensity contribution */
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/* =================================================== */
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diffusecolor = *diff_col;
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pika_rgb_multiply (&diffusecolor, mapvals.material.diffuse_ref);
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pika_rgb_multiply (&diffusecolor, NL);
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specularcolor = *spec_col;
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pika_rgb_multiply (&specularcolor, mapvals.material.specular_ref);
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pika_rgb_multiply (&specularcolor, RV);
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pika_rgb_add (&diffusecolor, &specularcolor);
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pika_rgb_multiply (&diffusecolor, mapvals.material.diffuse_int);
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pika_rgb_clamp (&diffusecolor);
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pika_rgb_add (&ambientcolor, &diffusecolor);
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}
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return ambientcolor;
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}
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static gint
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plane_intersect (PikaVector3 *dir,
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PikaVector3 *viewp,
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PikaVector3 *ipos,
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gdouble *u,
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gdouble *v)
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{
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static gdouble det, det1, det2, det3, t;
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imat[0][0] = dir->x;
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imat[1][0] = dir->y;
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imat[2][0] = dir->z;
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/* Compute determinant of the first 3x3 sub matrix (denominator) */
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/* ============================================================= */
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det = (imat[0][0] * imat[1][1] * imat[2][2] +
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imat[0][1] * imat[1][2] * imat[2][0] +
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imat[0][2] * imat[1][0] * imat[2][1] -
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imat[0][2] * imat[1][1] * imat[2][0] -
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imat[0][0] * imat[1][2] * imat[2][1] -
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imat[2][2] * imat[0][1] * imat[1][0]);
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/* If the determinant is non-zero, a intersection point exists */
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/* =========================================================== */
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if (det != 0.0)
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{
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/* Now, lets compute the numerator determinants (wow ;) */
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/* ==================================================== */
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det1 = (imat[0][3] * imat[1][1] * imat[2][2] +
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imat[0][1] * imat[1][2] * imat[2][3] +
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imat[0][2] * imat[1][3] * imat[2][1] -
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imat[0][2] * imat[1][1] * imat[2][3] -
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imat[1][2] * imat[2][1] * imat[0][3] -
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imat[2][2] * imat[0][1] * imat[1][3]);
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det2 = (imat[0][0] * imat[1][3] * imat[2][2] +
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imat[0][3] * imat[1][2] * imat[2][0] +
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imat[0][2] * imat[1][0] * imat[2][3] -
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imat[0][2] * imat[1][3] * imat[2][0] -
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imat[1][2] * imat[2][3] * imat[0][0] -
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imat[2][2] * imat[0][3] * imat[1][0]);
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det3 = (imat[0][0] * imat[1][1] * imat[2][3] +
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imat[0][1] * imat[1][3] * imat[2][0] +
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imat[0][3] * imat[1][0] * imat[2][1] -
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imat[0][3] * imat[1][1] * imat[2][0] -
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imat[1][3] * imat[2][1] * imat[0][0] -
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imat[2][3] * imat[0][1] * imat[1][0]);
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/* Now we have the simultaneous solutions. Lets compute the unknowns */
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/* (skip u&v if t is <0, this means the intersection is behind us) */
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/* ================================================================ */
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t = det1 / det;
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if (t > 0.0)
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{
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*u = 1.0 + ((det2 / det) - 0.5);
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*v = 1.0 + ((det3 / det) - 0.5);
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ipos->x = viewp->x + t * dir->x;
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ipos->y = viewp->y + t * dir->y;
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ipos->z = viewp->z + t * dir->z;
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return TRUE;
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}
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}
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return FALSE;
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}
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/*****************************************************************************
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* These routines computes the color of the surface
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* of the plane at a given point
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*****************************************************************************/
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PikaRGB
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get_ray_color_plane (PikaVector3 *pos)
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{
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PikaRGB color = background;
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static gint inside = FALSE;
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static PikaVector3 ray, spos;
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static gdouble vx, vy;
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/* Construct a line from our VP to the point */
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/* ========================================= */
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pika_vector3_sub (&ray, pos, &mapvals.viewpoint);
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pika_vector3_normalize (&ray);
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/* Check for intersection. This is a quasi ray-tracer. */
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/* =================================================== */
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if (plane_intersect (&ray, &mapvals.viewpoint, &spos, &vx, &vy) == TRUE)
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{
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color = get_image_color (vx, vy, &inside);
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if (color.a != 0.0 && inside == TRUE &&
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mapvals.lightsource.type != NO_LIGHT)
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{
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/* Compute shading at this point */
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/* ============================= */
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color = phong_shade (&spos,
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&mapvals.viewpoint,
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&mapvals.normal,
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&color,
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&mapvals.lightsource.color,
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mapvals.lightsource.type);
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pika_rgb_clamp (&color);
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}
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}
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if (mapvals.transparent_background == FALSE && color.a < 1.0)
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{
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pika_rgb_composite (&color, &background,
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PIKA_RGB_COMPOSITE_BEHIND);
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}
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return color;
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}
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/***********************************************************************/
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/* Given the NorthPole, Equator and a third vector (normal) compute */
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/* the conversion from spherical oordinates to image space coordinates */
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/***********************************************************************/
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static void
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sphere_to_image (PikaVector3 *normal,
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gdouble *u,
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gdouble *v)
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{
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static gdouble alpha, fac;
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static PikaVector3 cross_prod;
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alpha = acos (-pika_vector3_inner_product (&mapvals.secondaxis, normal));
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*v = alpha / G_PI;
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if (*v == 0.0 || *v == 1.0)
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{
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*u = 0.0;
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}
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else
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{
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fac = (pika_vector3_inner_product (&mapvals.firstaxis, normal) /
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sin (alpha));
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/* Make sure that we map to -1.0..1.0 (take care of rounding errors) */
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/* ================================================================= */
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fac = CLAMP (fac, -1.0, 1.0);
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*u = acos (fac) / (2.0 * G_PI);
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cross_prod = pika_vector3_cross_product (&mapvals.secondaxis,
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&mapvals.firstaxis);
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if (pika_vector3_inner_product (&cross_prod, normal) < 0.0)
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*u = 1.0 - *u;
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}
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}
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/***************************************************/
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/* Compute intersection point with sphere (if any) */
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/***************************************************/
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static gint
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sphere_intersect (PikaVector3 *dir,
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PikaVector3 *viewp,
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PikaVector3 *spos1,
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PikaVector3 *spos2)
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{
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static gdouble alpha, beta, tau, s1, s2, tmp;
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static PikaVector3 t;
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pika_vector3_sub (&t, &mapvals.position, viewp);
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alpha = pika_vector3_inner_product (dir, &t);
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beta = pika_vector3_inner_product (&t, &t);
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tau = alpha * alpha - beta + mapvals.radius * mapvals.radius;
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if (tau >= 0.0)
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{
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tau = sqrt (tau);
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s1 = alpha + tau;
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s2 = alpha - tau;
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if (s2 < s1)
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{
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tmp = s1;
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s1 = s2;
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s2 = tmp;
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}
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spos1->x = viewp->x + s1 * dir->x;
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spos1->y = viewp->y + s1 * dir->y;
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spos1->z = viewp->z + s1 * dir->z;
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spos2->x = viewp->x + s2 * dir->x;
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spos2->y = viewp->y + s2 * dir->y;
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spos2->z = viewp->z + s2 * dir->z;
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return TRUE;
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}
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return FALSE;
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}
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/*****************************************************************************
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* These routines computes the color of the surface
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* of the sphere at a given point
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*****************************************************************************/
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PikaRGB
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get_ray_color_sphere (PikaVector3 *pos)
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{
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PikaRGB color = background;
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static PikaRGB color2;
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static gint inside = FALSE;
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static PikaVector3 normal, ray, spos1, spos2;
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static gdouble vx, vy;
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/* Check if ray is within the bounding box */
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/* ======================================= */
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if (pos->x<bx1 || pos->x>bx2 || pos->y<by1 || pos->y>by2)
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return color;
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/* Construct a line from our VP to the point */
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/* ========================================= */
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pika_vector3_sub (&ray, pos, &mapvals.viewpoint);
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pika_vector3_normalize (&ray);
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/* Check for intersection. This is a quasi ray-tracer. */
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/* =================================================== */
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if (sphere_intersect (&ray, &mapvals.viewpoint, &spos1, &spos2) == TRUE)
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{
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/* Compute spherical to rectangular mapping */
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/* ======================================== */
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pika_vector3_sub (&normal, &spos1, &mapvals.position);
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pika_vector3_normalize (&normal);
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sphere_to_image (&normal, &vx, &vy);
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color = get_image_color (vx, vy, &inside);
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/* Check for total transparency... */
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/* =============================== */
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if (color.a < 1.0)
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{
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/* Hey, we can see through here! */
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/* Lets see what's on the other side.. */
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/* =================================== */
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color = phong_shade (&spos1,
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&mapvals.viewpoint,
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&normal,
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&color,
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&mapvals.lightsource.color,
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mapvals.lightsource.type);
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pika_rgb_clamp (&color);
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pika_vector3_sub (&normal, &spos2, &mapvals.position);
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pika_vector3_normalize (&normal);
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sphere_to_image (&normal, &vx, &vy);
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color2 = get_image_color (vx, vy, &inside);
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/* Make the normal point inwards */
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/* ============================= */
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pika_vector3_mul (&normal, -1.0);
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color2 = phong_shade (&spos2,
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&mapvals.viewpoint,
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&normal,
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&color2,
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&mapvals.lightsource.color,
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mapvals.lightsource.type);
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pika_rgb_clamp (&color2);
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/* Compute a mix of the first and second colors */
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/* ============================================ */
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pika_rgb_composite (&color, &color2, PIKA_RGB_COMPOSITE_NORMAL);
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pika_rgb_clamp (&color);
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}
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else if (color.a != 0.0 &&
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inside == TRUE &&
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mapvals.lightsource.type != NO_LIGHT)
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{
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/* Compute shading at this point */
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/* ============================= */
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color = phong_shade (&spos1,
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&mapvals.viewpoint,
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&normal,
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&color,
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&mapvals.lightsource.color,
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mapvals.lightsource.type);
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pika_rgb_clamp (&color);
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}
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}
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if (mapvals.transparent_background == FALSE && color.a < 1.0)
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{
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pika_rgb_composite (&color, &background,
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PIKA_RGB_COMPOSITE_BEHIND);
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}
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return color;
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}
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/***************************************************/
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/* Transform the corners of the bounding box to 2D */
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/***************************************************/
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void
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compute_bounding_box (void)
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{
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PikaVector3 p1, p2;
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gdouble t;
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PikaVector3 dir;
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p1 = mapvals.position;
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p1.x -= (mapvals.radius + 0.01);
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p1.y -= (mapvals.radius + 0.01);
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p2 = mapvals.position;
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p2.x += (mapvals.radius + 0.01);
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p2.y += (mapvals.radius + 0.01);
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pika_vector3_sub (&dir, &p1, &mapvals.viewpoint);
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pika_vector3_normalize (&dir);
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if (dir.z != 0.0)
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{
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t = (-1.0 * mapvals.viewpoint.z) / dir.z;
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p1.x = (mapvals.viewpoint.x + t * dir.x);
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p1.y = (mapvals.viewpoint.y + t * dir.y);
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}
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pika_vector3_sub (&dir, &p2, &mapvals.viewpoint);
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pika_vector3_normalize (&dir);
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if (dir.z != 0.0)
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{
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t = (-1.0 * mapvals.viewpoint.z) / dir.z;
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p2.x = (mapvals.viewpoint.x + t * dir.x);
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p2.y = (mapvals.viewpoint.y + t * dir.y);
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}
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bx1 = p1.x;
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by1 = p1.y;
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bx2 = p2.x;
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by2 = p2.y;
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}
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/* These two were taken from the Mesa source. Mesa is written */
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/* and is (C) by Brian Paul. vecmulmat() performs a post-mul by */
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/* a 4x4 matrix to a 1x4(3) vector. rotmat() creates a matrix */
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/* that by post-mul will rotate a 1x4(3) vector the given angle */
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/* about the given axis. */
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/* ============================================================ */
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void
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vecmulmat (PikaVector3 *u,
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PikaVector3 *v,
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gfloat m[16])
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{
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gfloat v0=v->x, v1=v->y, v2=v->z;
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#define M(row,col) m[col*4+row]
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u->x = v0 * M(0,0) + v1 * M(1,0) + v2 * M(2,0) + M(3,0);
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u->y = v0 * M(0,1) + v1 * M(1,1) + v2 * M(2,1) + M(3,1);
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u->z = v0 * M(0,2) + v1 * M(1,2) + v2 * M(2,2) + M(3,2);
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#undef M
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}
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void
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rotatemat (gfloat angle,
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PikaVector3 *v,
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gfloat m[16])
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{
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/* This function contributed by Erich Boleyn (erich@uruk.org) */
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gfloat mag, s, c;
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gfloat xx, yy, zz, xy, yz, zx, xs, ys, zs, one_c;
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gfloat IdentityMat[16];
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gint cnt;
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s = sin (angle * (G_PI / 180.0));
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c = cos (angle * (G_PI / 180.0));
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mag = sqrt (v->x*v->x + v->y*v->y + v->z*v->z);
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if (mag == 0.0)
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{
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/* generate an identity matrix and return */
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for (cnt = 0; cnt < 16; cnt++)
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IdentityMat[cnt] = 0.0;
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IdentityMat[0] = 1.0;
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IdentityMat[5] = 1.0;
|
|
IdentityMat[10] = 1.0;
|
|
IdentityMat[15] = 1.0;
|
|
|
|
memcpy (m, IdentityMat, sizeof (gfloat) * 16);
|
|
return;
|
|
}
|
|
|
|
v->x /= mag;
|
|
v->y /= mag;
|
|
v->z /= mag;
|
|
|
|
#define M(row,col) m[col*4+row]
|
|
|
|
xx = v->x * v->x;
|
|
yy = v->y * v->y;
|
|
zz = v->z * v->z;
|
|
xy = v->x * v->y;
|
|
yz = v->y * v->z;
|
|
zx = v->z * v->x;
|
|
xs = v->x * s;
|
|
ys = v->y * s;
|
|
zs = v->z * s;
|
|
one_c = 1.0F - c;
|
|
|
|
M(0,0) = (one_c * xx) + c;
|
|
M(0,1) = (one_c * xy) - zs;
|
|
M(0,2) = (one_c * zx) + ys;
|
|
M(0,3) = 0.0F;
|
|
|
|
M(1,0) = (one_c * xy) + zs;
|
|
M(1,1) = (one_c * yy) + c;
|
|
M(1,2) = (one_c * yz) - xs;
|
|
M(1,3) = 0.0F;
|
|
|
|
M(2,0) = (one_c * zx) - ys;
|
|
M(2,1) = (one_c * yz) + xs;
|
|
M(2,2) = (one_c * zz) + c;
|
|
M(2,3) = 0.0F;
|
|
|
|
M(3,0) = 0.0F;
|
|
M(3,1) = 0.0F;
|
|
M(3,2) = 0.0F;
|
|
M(3,3) = 1.0F;
|
|
|
|
#undef M
|
|
}
|
|
|
|
/* Transpose the matrix m. If m is orthogonal (like a rotation matrix), */
|
|
/* this is equal to the inverse of the matrix. */
|
|
/* ==================================================================== */
|
|
|
|
void
|
|
transpose_mat (gfloat m[16])
|
|
{
|
|
gint i, j;
|
|
gfloat t;
|
|
|
|
for (i = 0; i < 4; i++)
|
|
{
|
|
for (j = 0; j < i; j++)
|
|
{
|
|
t = m[j*4+i];
|
|
m[j*4+i] = m[i*4+j];
|
|
m[i*4+j] = t;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Compute the matrix product c=a*b */
|
|
/* ================================ */
|
|
|
|
void
|
|
matmul (gfloat a[16],
|
|
gfloat b[16],
|
|
gfloat c[16])
|
|
{
|
|
gint i, j, k;
|
|
gfloat value;
|
|
|
|
#define A(row,col) a[col*4+row]
|
|
#define B(row,col) b[col*4+row]
|
|
#define C(row,col) c[col*4+row]
|
|
|
|
for (i = 0; i < 4; i++)
|
|
{
|
|
for (j = 0; j < 4; j++)
|
|
{
|
|
value = 0.0;
|
|
|
|
for (k = 0; k < 4; k++)
|
|
value += A(i,k) * B(k,j);
|
|
|
|
C(i,j) = value;
|
|
}
|
|
}
|
|
|
|
#undef A
|
|
#undef B
|
|
#undef C
|
|
}
|
|
|
|
void
|
|
ident_mat (gfloat m[16])
|
|
{
|
|
gint i, j;
|
|
|
|
#define M(row,col) m[col*4+row]
|
|
|
|
for (i = 0; i < 4; i++)
|
|
{
|
|
for (j = 0; j < 4; j++)
|
|
{
|
|
if (i == j)
|
|
M(i,j) = 1.0;
|
|
else
|
|
M(i,j) = 0.0;
|
|
}
|
|
}
|
|
|
|
#undef M
|
|
}
|
|
|
|
static gboolean
|
|
intersect_rect (gdouble u,
|
|
gdouble v,
|
|
gdouble w,
|
|
PikaVector3 viewp,
|
|
PikaVector3 dir,
|
|
FaceIntersectInfo *face_info)
|
|
{
|
|
gboolean result = FALSE;
|
|
gdouble u2, v2;
|
|
|
|
if (dir.z!=0.0)
|
|
{
|
|
u2 = u / 2.0;
|
|
v2 = v / 2.0;
|
|
|
|
face_info->t = (w-viewp.z) / dir.z;
|
|
face_info->s.x = viewp.x + face_info->t * dir.x;
|
|
face_info->s.y = viewp.y + face_info->t * dir.y;
|
|
face_info->s.z = w;
|
|
|
|
if (face_info->s.x >= -u2 && face_info->s.x <= u2 &&
|
|
face_info->s.y >= -v2 && face_info->s.y <= v2)
|
|
{
|
|
face_info->u = (face_info->s.x + u2) / u;
|
|
face_info->v = (face_info->s.y + v2) / v;
|
|
result = TRUE;
|
|
}
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
static gboolean
|
|
intersect_box (PikaVector3 scale,
|
|
PikaVector3 viewp,
|
|
PikaVector3 dir,
|
|
FaceIntersectInfo *face_intersect)
|
|
{
|
|
PikaVector3 v, d, tmp, axis[3];
|
|
FaceIntersectInfo face_tmp;
|
|
gboolean result = FALSE;
|
|
gfloat m[16];
|
|
gint i = 0;
|
|
|
|
pika_vector3_set (&axis[0], 1.0, 0.0, 0.0);
|
|
pika_vector3_set (&axis[1], 0.0, 1.0, 0.0);
|
|
pika_vector3_set (&axis[2], 0.0, 0.0, 1.0);
|
|
|
|
/* Front side */
|
|
/* ========== */
|
|
|
|
if (intersect_rect (scale.x, scale.y, scale.z / 2.0,
|
|
viewp, dir, &face_intersect[i]) == TRUE)
|
|
{
|
|
face_intersect[i].face = 0;
|
|
pika_vector3_set (&face_intersect[i++].n, 0.0, 0.0, 1.0);
|
|
result = TRUE;
|
|
}
|
|
|
|
/* Back side */
|
|
/* ========= */
|
|
|
|
if (intersect_rect (scale.x, scale.y, -scale.z / 2.0,
|
|
viewp, dir, &face_intersect[i]) == TRUE)
|
|
{
|
|
face_intersect[i].face = 1;
|
|
face_intersect[i].u = 1.0 - face_intersect[i].u;
|
|
pika_vector3_set (&face_intersect[i++].n, 0.0, 0.0, -1.0);
|
|
result = TRUE;
|
|
}
|
|
|
|
/* Check if we've found the two possible intersection points */
|
|
/* ========================================================= */
|
|
|
|
if (i < 2)
|
|
{
|
|
/* Top: Rotate viewpoint and direction into rectangle's local coordinate system */
|
|
/* ============================================================================ */
|
|
|
|
rotatemat (90, &axis[0], m);
|
|
vecmulmat (&v, &viewp, m);
|
|
vecmulmat (&d, &dir, m);
|
|
|
|
if (intersect_rect (scale.x, scale.z, scale.y / 2.0,
|
|
v, d, &face_intersect[i]) == TRUE)
|
|
{
|
|
face_intersect[i].face = 2;
|
|
|
|
transpose_mat (m);
|
|
vecmulmat(&tmp, &face_intersect[i].s, m);
|
|
face_intersect[i].s = tmp;
|
|
|
|
pika_vector3_set (&face_intersect[i++].n, 0.0, -1.0, 0.0);
|
|
result = TRUE;
|
|
}
|
|
}
|
|
|
|
/* Check if we've found the two possible intersection points */
|
|
/* ========================================================= */
|
|
|
|
if (i < 2)
|
|
{
|
|
/* Bottom: Rotate viewpoint and direction into rectangle's local coordinate system */
|
|
/* =============================================================================== */
|
|
|
|
rotatemat (90, &axis[0], m);
|
|
vecmulmat (&v, &viewp, m);
|
|
vecmulmat (&d, &dir, m);
|
|
|
|
if (intersect_rect (scale.x, scale.z, -scale.y / 2.0,
|
|
v, d, &face_intersect[i]) == TRUE)
|
|
{
|
|
face_intersect[i].face = 3;
|
|
|
|
transpose_mat (m);
|
|
|
|
vecmulmat (&tmp, &face_intersect[i].s, m);
|
|
face_intersect[i].s = tmp;
|
|
|
|
face_intersect[i].v = 1.0 - face_intersect[i].v;
|
|
|
|
pika_vector3_set (&face_intersect[i++].n, 0.0, 1.0, 0.0);
|
|
|
|
result = TRUE;
|
|
}
|
|
}
|
|
|
|
/* Check if we've found the two possible intersection points */
|
|
/* ========================================================= */
|
|
|
|
if (i < 2)
|
|
{
|
|
/* Left side: Rotate viewpoint and direction into rectangle's local coordinate system */
|
|
/* ================================================================================== */
|
|
|
|
rotatemat (90, &axis[1], m);
|
|
vecmulmat (&v, &viewp, m);
|
|
vecmulmat (&d, &dir, m);
|
|
|
|
if (intersect_rect (scale.z, scale.y, scale.x / 2.0,
|
|
v, d, &face_intersect[i]) == TRUE)
|
|
{
|
|
face_intersect[i].face = 4;
|
|
|
|
transpose_mat (m);
|
|
vecmulmat (&tmp, &face_intersect[i].s, m);
|
|
face_intersect[i].s = tmp;
|
|
|
|
pika_vector3_set (&face_intersect[i++].n, 1.0, 0.0, 0.0);
|
|
result = TRUE;
|
|
}
|
|
}
|
|
|
|
/* Check if we've found the two possible intersection points */
|
|
/* ========================================================= */
|
|
|
|
if (i < 2)
|
|
{
|
|
/* Right side: Rotate viewpoint and direction into rectangle's local coordinate system */
|
|
/* =================================================================================== */
|
|
|
|
rotatemat (90, &axis[1], m);
|
|
vecmulmat (&v, &viewp, m);
|
|
vecmulmat (&d, &dir, m);
|
|
|
|
if (intersect_rect (scale.z, scale.y, -scale.x / 2.0,
|
|
v, d, &face_intersect[i]) == TRUE)
|
|
{
|
|
face_intersect[i].face = 5;
|
|
|
|
transpose_mat (m);
|
|
vecmulmat (&tmp, &face_intersect[i].s, m);
|
|
|
|
face_intersect[i].u = 1.0 - face_intersect[i].u;
|
|
|
|
pika_vector3_set (&face_intersect[i++].n, -1.0, 0.0, 0.0);
|
|
result = TRUE;
|
|
}
|
|
}
|
|
|
|
/* Sort intersection points */
|
|
/* ======================== */
|
|
|
|
if (face_intersect[0].t > face_intersect[1].t)
|
|
{
|
|
face_tmp = face_intersect[0];
|
|
face_intersect[0] = face_intersect[1];
|
|
face_intersect[1] = face_tmp;
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
PikaRGB
|
|
get_ray_color_box (PikaVector3 *pos)
|
|
{
|
|
PikaVector3 lvp, ldir, vp, p, dir, ns, nn;
|
|
PikaRGB color, color2;
|
|
gfloat m[16];
|
|
gint i;
|
|
FaceIntersectInfo face_intersect[2];
|
|
|
|
color = background;
|
|
vp = mapvals.viewpoint;
|
|
p = *pos;
|
|
|
|
/* Translate viewpoint so that the box has its origin */
|
|
/* at its lower left corner. */
|
|
/* ================================================== */
|
|
|
|
vp.x = vp.x - mapvals.position.x;
|
|
vp.y = vp.y - mapvals.position.y;
|
|
vp.z = vp.z - mapvals.position.z;
|
|
|
|
p.x = p.x - mapvals.position.x;
|
|
p.y = p.y - mapvals.position.y;
|
|
p.z = p.z - mapvals.position.z;
|
|
|
|
/* Compute direction */
|
|
/* ================= */
|
|
|
|
pika_vector3_sub (&dir, &p, &vp);
|
|
pika_vector3_normalize (&dir);
|
|
|
|
/* Compute inverse of rotation matrix and apply it to */
|
|
/* the viewpoint and direction. This transforms the */
|
|
/* observer into the local coordinate system of the box */
|
|
/* ==================================================== */
|
|
|
|
memcpy (m, rotmat, sizeof (gfloat) * 16);
|
|
|
|
transpose_mat (m);
|
|
|
|
vecmulmat (&lvp, &vp, m);
|
|
vecmulmat (&ldir, &dir, m);
|
|
|
|
/* Ok. Now the observer is in the space where the box is located */
|
|
/* with its lower left corner at the origin and its axis aligned */
|
|
/* to the cartesian basis. Check if the transformed ray hits it. */
|
|
/* ============================================================= */
|
|
|
|
face_intersect[0].t = 1000000.0;
|
|
face_intersect[1].t = 1000000.0;
|
|
|
|
if (intersect_box (mapvals.scale, lvp, ldir, face_intersect) == TRUE)
|
|
{
|
|
/* We've hit the box. Transform the hit points and */
|
|
/* normals back into the world coordinate system */
|
|
/* =============================================== */
|
|
|
|
for (i = 0; i < 2; i++)
|
|
{
|
|
vecmulmat (&ns, &face_intersect[i].s, rotmat);
|
|
vecmulmat (&nn, &face_intersect[i].n, rotmat);
|
|
|
|
ns.x = ns.x + mapvals.position.x;
|
|
ns.y = ns.y + mapvals.position.y;
|
|
ns.z = ns.z + mapvals.position.z;
|
|
|
|
face_intersect[i].s = ns;
|
|
face_intersect[i].n = nn;
|
|
}
|
|
|
|
color = get_box_image_color (face_intersect[0].face,
|
|
face_intersect[0].u,
|
|
face_intersect[0].v);
|
|
|
|
/* Check for total transparency... */
|
|
/* =============================== */
|
|
|
|
if (color.a < 1.0)
|
|
{
|
|
/* Hey, we can see through here! */
|
|
/* Lets see what's on the other side.. */
|
|
/* =================================== */
|
|
|
|
color = phong_shade (&face_intersect[0].s,
|
|
&mapvals.viewpoint,
|
|
&face_intersect[0].n,
|
|
&color,
|
|
&mapvals.lightsource.color,
|
|
mapvals.lightsource.type);
|
|
|
|
pika_rgb_clamp (&color);
|
|
|
|
color2 = get_box_image_color (face_intersect[1].face,
|
|
face_intersect[1].u,
|
|
face_intersect[1].v);
|
|
|
|
/* Make the normal point inwards */
|
|
/* ============================= */
|
|
|
|
pika_vector3_mul (&face_intersect[1].n, -1.0);
|
|
|
|
color2 = phong_shade (&face_intersect[1].s,
|
|
&mapvals.viewpoint,
|
|
&face_intersect[1].n,
|
|
&color2,
|
|
&mapvals.lightsource.color,
|
|
mapvals.lightsource.type);
|
|
|
|
pika_rgb_clamp (&color2);
|
|
|
|
if (mapvals.transparent_background == FALSE && color2.a < 1.0)
|
|
{
|
|
pika_rgb_composite (&color2, &background,
|
|
PIKA_RGB_COMPOSITE_BEHIND);
|
|
}
|
|
|
|
/* Compute a mix of the first and second colors */
|
|
/* ============================================ */
|
|
|
|
pika_rgb_composite (&color, &color2, PIKA_RGB_COMPOSITE_NORMAL);
|
|
pika_rgb_clamp (&color);
|
|
}
|
|
else if (color.a != 0.0 && mapvals.lightsource.type != NO_LIGHT)
|
|
{
|
|
color = phong_shade (&face_intersect[0].s,
|
|
&mapvals.viewpoint,
|
|
&face_intersect[0].n,
|
|
&color,
|
|
&mapvals.lightsource.color,
|
|
mapvals.lightsource.type);
|
|
|
|
pika_rgb_clamp (&color);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (mapvals.transparent_background == TRUE)
|
|
pika_rgb_set_alpha (&color, 0.0);
|
|
}
|
|
|
|
return color;
|
|
}
|
|
|
|
static gboolean
|
|
intersect_circle (PikaVector3 vp,
|
|
PikaVector3 dir,
|
|
gdouble w,
|
|
FaceIntersectInfo *face_info)
|
|
{
|
|
gboolean result = FALSE;
|
|
gdouble r, d;
|
|
|
|
#define sqr(a) (a*a)
|
|
|
|
if (dir.y != 0.0)
|
|
{
|
|
face_info->t = (w-vp.y)/dir.y;
|
|
face_info->s.x = vp.x + face_info->t*dir.x;
|
|
face_info->s.y = w;
|
|
face_info->s.z = vp.z + face_info->t*dir.z;
|
|
|
|
r = sqrt (sqr (face_info->s.x) + sqr (face_info->s.z));
|
|
|
|
if (r <= mapvals.cylinder_radius)
|
|
{
|
|
d = 2.0 * mapvals.cylinder_radius;
|
|
face_info->u = (face_info->s.x + mapvals.cylinder_radius) / d;
|
|
face_info->v = (face_info->s.z + mapvals.cylinder_radius) / d;
|
|
result = TRUE;
|
|
}
|
|
}
|
|
|
|
#undef sqr
|
|
|
|
return result;
|
|
}
|
|
|
|
static gboolean
|
|
intersect_cylinder (PikaVector3 vp,
|
|
PikaVector3 dir,
|
|
FaceIntersectInfo *face_intersect)
|
|
{
|
|
gdouble a, b, c, d, e, f, tmp, l;
|
|
gboolean result = FALSE;
|
|
gint i;
|
|
|
|
#define sqr(a) (a*a)
|
|
|
|
a = sqr (dir.x) + sqr (dir.z);
|
|
b = 2.0 * (vp.x * dir.x + vp.z * dir.z);
|
|
c = sqr (vp.x) + sqr (vp.z) - sqr (mapvals.cylinder_radius);
|
|
|
|
d = sqr (b) - 4.0 * a * c;
|
|
|
|
if (d >= 0.0)
|
|
{
|
|
e = sqrt (d);
|
|
f = 2.0 * a;
|
|
|
|
if (f != 0.0)
|
|
{
|
|
result = TRUE;
|
|
|
|
face_intersect[0].t = (-b+e)/f;
|
|
face_intersect[1].t = (-b-e)/f;
|
|
|
|
if (face_intersect[0].t>face_intersect[1].t)
|
|
{
|
|
tmp = face_intersect[0].t;
|
|
face_intersect[0].t = face_intersect[1].t;
|
|
face_intersect[1].t = tmp;
|
|
}
|
|
|
|
for (i = 0; i < 2; i++)
|
|
{
|
|
face_intersect[i].s.x = vp.x + face_intersect[i].t * dir.x;
|
|
face_intersect[i].s.y = vp.y + face_intersect[i].t * dir.y;
|
|
face_intersect[i].s.z = vp.z + face_intersect[i].t * dir.z;
|
|
|
|
face_intersect[i].n = face_intersect[i].s;
|
|
face_intersect[i].n.y = 0.0;
|
|
pika_vector3_normalize(&face_intersect[i].n);
|
|
|
|
l = mapvals.cylinder_length/2.0;
|
|
|
|
face_intersect[i].u = (atan2(face_intersect[i].s.x,face_intersect[i].s.z)+G_PI)/(2.0*G_PI);
|
|
face_intersect[i].v = (face_intersect[i].s.y+l)/mapvals.cylinder_length;
|
|
|
|
/* Mark hitpoint as on the cylinder hull */
|
|
/* ===================================== */
|
|
|
|
face_intersect[i].face = 0;
|
|
|
|
/* Check if we're completely off the cylinder axis */
|
|
/* =============================================== */
|
|
|
|
if (face_intersect[i].s.y>l || face_intersect[i].s.y<-l)
|
|
{
|
|
/* Check if we've hit a cap */
|
|
/* ======================== */
|
|
|
|
if (face_intersect[i].s.y>l)
|
|
{
|
|
if (intersect_circle(vp,dir,l,&face_intersect[i])==FALSE)
|
|
result = FALSE;
|
|
else
|
|
{
|
|
face_intersect[i].face = 2;
|
|
face_intersect[i].v = 1 - face_intersect[i].v;
|
|
pika_vector3_set(&face_intersect[i].n, 0.0, 1.0, 0.0);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (intersect_circle(vp,dir,-l,&face_intersect[i])==FALSE)
|
|
result = FALSE;
|
|
else
|
|
{
|
|
face_intersect[i].face = 1;
|
|
pika_vector3_set(&face_intersect[i].n, 0.0, -1.0, 0.0);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#undef sqr
|
|
|
|
return result;
|
|
}
|
|
|
|
static PikaRGB
|
|
get_cylinder_color (gint face,
|
|
gdouble u,
|
|
gdouble v)
|
|
{
|
|
PikaRGB color;
|
|
gint inside;
|
|
|
|
if (face == 0)
|
|
color = get_image_color (u, v, &inside);
|
|
else
|
|
color = get_cylinder_image_color (face - 1, u, v);
|
|
|
|
return color;
|
|
}
|
|
|
|
PikaRGB
|
|
get_ray_color_cylinder (PikaVector3 *pos)
|
|
{
|
|
PikaVector3 lvp, ldir, vp, p, dir, ns, nn;
|
|
PikaRGB color, color2;
|
|
gfloat m[16];
|
|
gint i;
|
|
FaceIntersectInfo face_intersect[2];
|
|
|
|
color = background;
|
|
vp = mapvals.viewpoint;
|
|
p = *pos;
|
|
|
|
vp.x = vp.x - mapvals.position.x;
|
|
vp.y = vp.y - mapvals.position.y;
|
|
vp.z = vp.z - mapvals.position.z;
|
|
|
|
p.x = p.x - mapvals.position.x;
|
|
p.y = p.y - mapvals.position.y;
|
|
p.z = p.z - mapvals.position.z;
|
|
|
|
/* Compute direction */
|
|
/* ================= */
|
|
|
|
pika_vector3_sub (&dir, &p, &vp);
|
|
pika_vector3_normalize (&dir);
|
|
|
|
/* Compute inverse of rotation matrix and apply it to */
|
|
/* the viewpoint and direction. This transforms the */
|
|
/* observer into the local coordinate system of the box */
|
|
/* ==================================================== */
|
|
|
|
memcpy (m, rotmat, sizeof (gfloat) * 16);
|
|
|
|
transpose_mat (m);
|
|
|
|
vecmulmat (&lvp, &vp, m);
|
|
vecmulmat (&ldir, &dir, m);
|
|
|
|
if (intersect_cylinder (lvp, ldir, face_intersect) == TRUE)
|
|
{
|
|
/* We've hit the cylinder. Transform the hit points and */
|
|
/* normals back into the world coordinate system */
|
|
/* ==================================================== */
|
|
|
|
for (i = 0; i < 2; i++)
|
|
{
|
|
vecmulmat (&ns, &face_intersect[i].s, rotmat);
|
|
vecmulmat (&nn, &face_intersect[i].n, rotmat);
|
|
|
|
ns.x = ns.x + mapvals.position.x;
|
|
ns.y = ns.y + mapvals.position.y;
|
|
ns.z = ns.z + mapvals.position.z;
|
|
|
|
face_intersect[i].s = ns;
|
|
face_intersect[i].n = nn;
|
|
}
|
|
|
|
color = get_cylinder_color (face_intersect[0].face,
|
|
face_intersect[0].u,
|
|
face_intersect[0].v);
|
|
|
|
/* Check for transparency... */
|
|
/* ========================= */
|
|
|
|
if (color.a < 1.0)
|
|
{
|
|
/* Hey, we can see through here! */
|
|
/* Lets see what's on the other side.. */
|
|
/* =================================== */
|
|
|
|
color = phong_shade (&face_intersect[0].s,
|
|
&mapvals.viewpoint,
|
|
&face_intersect[0].n,
|
|
&color,
|
|
&mapvals.lightsource.color,
|
|
mapvals.lightsource.type);
|
|
|
|
pika_rgb_clamp (&color);
|
|
|
|
color2 = get_cylinder_color (face_intersect[1].face,
|
|
face_intersect[1].u,
|
|
face_intersect[1].v);
|
|
|
|
/* Make the normal point inwards */
|
|
/* ============================= */
|
|
|
|
pika_vector3_mul (&face_intersect[1].n, -1.0);
|
|
|
|
color2 = phong_shade (&face_intersect[1].s,
|
|
&mapvals.viewpoint,
|
|
&face_intersect[1].n,
|
|
&color2,
|
|
&mapvals.lightsource.color,
|
|
mapvals.lightsource.type);
|
|
|
|
pika_rgb_clamp (&color2);
|
|
|
|
if (mapvals.transparent_background == FALSE && color2.a < 1.0)
|
|
{
|
|
pika_rgb_composite (&color2, &background,
|
|
PIKA_RGB_COMPOSITE_BEHIND);
|
|
}
|
|
|
|
/* Compute a mix of the first and second colors */
|
|
/* ============================================ */
|
|
|
|
pika_rgb_composite (&color, &color2, PIKA_RGB_COMPOSITE_NORMAL);
|
|
pika_rgb_clamp (&color);
|
|
}
|
|
else if (color.a != 0.0 && mapvals.lightsource.type != NO_LIGHT)
|
|
{
|
|
color = phong_shade (&face_intersect[0].s,
|
|
&mapvals.viewpoint,
|
|
&face_intersect[0].n,
|
|
&color,
|
|
&mapvals.lightsource.color,
|
|
mapvals.lightsource.type);
|
|
|
|
pika_rgb_clamp (&color);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (mapvals.transparent_background == TRUE)
|
|
pika_rgb_set_alpha (&color, 0.0);
|
|
}
|
|
|
|
return color;
|
|
}
|
