Rename raytrace.{c,h} to ray_trace.{c,h}.

1 files changed, 0 insertions, 503 deletions

diff --git a/libdimension/raytrace.c b/libdimension/raytrace.c
deleted file mode 100644
index dd84a26..0000000
--- a/libdimension/raytrace.c
+++ /dev/null
@@ -1,503 +0,0 @@
-/*************************************************************************
- * Copyright (C) 2010-2011 Tavian Barnes <tavianator@tavianator.com>     *
- *                                                                       *
- * This file is part of The Dimension Library.                           *
- *                                                                       *
- * The Dimension Library is free software; you can redistribute it and/  *
- * or modify it under the terms of the GNU Lesser General Public License *
- * as published by the Free Software Foundation; either version 3 of the *
- * License, or (at your option) any later version.                       *
- *                                                                       *
- * The Dimension 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  *
- * Lesser General Public License for more details.                       *
- *                                                                       *
- * You should have received a copy of the GNU Lesser General Public      *
- * License along with this program.  If not, see                         *
- * <http://www.gnu.org/licenses/>.                                       *
- *************************************************************************/
-
-/**
- * @file
- * The ray-tracing algorithm.
- */
-
-#include "dimension-internal.h"
-#include <stdlib.h>
-
-/*
- * Boilerplate for multithreading
- */
-
-/** Payload type for passing arguments to worker threads. */
-typedef struct {
-  dmnsn_future *future;
-  dmnsn_scene *scene;
-  dmnsn_prtree *prtree;
-} dmnsn_ray_trace_payload;
-
-/* Ray-trace a scene */
-void
-dmnsn_ray_trace(dmnsn_scene *scene)
-{
-  dmnsn_future *future = dmnsn_ray_trace_async(scene);
-  if (dmnsn_future_join(future) != 0) {
-    dmnsn_error("Error occured while ray-tracing.");
-  }
-}
-
-/** Background thread callback. */
-static int dmnsn_ray_trace_scene_thread(void *ptr);
-
-/* Ray-trace a scene in the background */
-dmnsn_future *
-dmnsn_ray_trace_async(dmnsn_scene *scene)
-{
-  dmnsn_future *future = dmnsn_new_future();
-
-  dmnsn_ray_trace_payload *payload =
-    dmnsn_malloc(sizeof(dmnsn_ray_trace_payload));
-  payload->future = future;
-  payload->scene  = scene;
-
-  dmnsn_new_thread(future, dmnsn_ray_trace_scene_thread, payload);
-
-  return future;
-}
-
-/** Worker thread callback. */
-static int dmnsn_ray_trace_scene_concurrent(void *ptr, unsigned int thread,
-                                            unsigned int nthreads);
-
-/* Thread callback -- set up the multithreaded engine */
-static int
-dmnsn_ray_trace_scene_thread(void *ptr)
-{
-  dmnsn_ray_trace_payload *payload = ptr;
-
-  /* Pre-calculate bounding box transformations, etc. */
-  dmnsn_scene_initialize(payload->scene);
-
-  /* Time the bounding tree construction */
-  dmnsn_timer_start(&payload->scene->bounding_timer);
-    payload->prtree = dmnsn_new_prtree(payload->scene->objects);
-  dmnsn_timer_stop(&payload->scene->bounding_timer);
-
-  /* Set up the future object */
-  dmnsn_future_set_total(payload->future, payload->scene->canvas->height);
-
-  /* Time the render itself */
-  dmnsn_timer_start(&payload->scene->render_timer);
-    int ret = dmnsn_execute_concurrently(dmnsn_ray_trace_scene_concurrent,
-                                         payload, payload->scene->nthreads);
-  dmnsn_timer_stop(&payload->scene->render_timer);
-
-  dmnsn_delete_prtree(payload->prtree);
-  dmnsn_free(payload);
-
-  return ret;
-}
-
-/*
- * Ray-tracing algorithm
- */
-
-/** The current state of the ray-tracing engine. */
-typedef struct dmnsn_rtstate {
-  const struct dmnsn_rtstate *parent;
-
-  const dmnsn_scene *scene;
-  const dmnsn_intersection *intersection;
-  const dmnsn_texture *texture;
-  const dmnsn_interior *interior;
-  const dmnsn_prtree *prtree;
-  unsigned int reclevel;
-
-  dmnsn_vector r;
-  dmnsn_vector pigment_r;
-  dmnsn_vector viewer;
-  dmnsn_vector reflected;
-  dmnsn_vector light;
-
-  dmnsn_color pigment;
-  dmnsn_color diffuse;
-  dmnsn_color additional;
-
-  double ior;
-
-  dmnsn_color adc_value;
-} dmnsn_rtstate;
-
-/** Compute a ray-tracing state from an intersection. */
-static inline void
-dmnsn_rtstate_initialize(dmnsn_rtstate *state,
-                         const dmnsn_intersection *intersection)
-{
-  state->intersection = intersection;
-  state->texture      = intersection->object->texture;
-  state->interior     = intersection->object->interior;
-
-  state->r = dmnsn_line_point(intersection->ray, intersection->t);
-  state->pigment_r = dmnsn_transform_point(
-    intersection->object->pigment_trans,
-    state->r
-  );
-  state->viewer = dmnsn_vector_normalized(
-    dmnsn_vector_negate(intersection->ray.n)
-  );
-  state->reflected = dmnsn_vector_sub(
-    dmnsn_vector_mul(
-      2*dmnsn_vector_dot(state->viewer, intersection->normal),
-      intersection->normal),
-    state->viewer
-  );
-
-  state->pigment    = dmnsn_black;
-  state->diffuse    = dmnsn_black;
-  state->additional = dmnsn_black;
-}
-
-/** Main helper for dmnsn_ray_trace_scene_impl - shoot a ray. */
-static dmnsn_color dmnsn_ray_shoot(dmnsn_rtstate *state, dmnsn_line ray);
-
-/* Actually ray-trace a scene */
-static int
-dmnsn_ray_trace_scene_concurrent(void *ptr, unsigned int thread,
-                                 unsigned int nthreads)
-{
-  const dmnsn_ray_trace_payload *payload = ptr;
-  dmnsn_future *future = payload->future;
-  dmnsn_scene *scene = payload->scene;
-  dmnsn_prtree *prtree = payload->prtree;
-
-  dmnsn_rtstate state = {
-    .parent = NULL,
-    .scene  = scene,
-    .prtree = prtree,
-  };
-
-  /* Iterate through each pixel */
-  for (size_t y = thread; y < scene->canvas->height; y += nthreads) {
-    for (size_t x = 0; x < scene->canvas->width; ++x) {
-      /* Get the ray corresponding to the (x,y)'th pixel */
-      dmnsn_line ray = dmnsn_camera_ray(
-        scene->camera,
-        ((double)(x + scene->region_x))/(scene->outer_width - 1),
-        ((double)(y + scene->region_y))/(scene->outer_height - 1)
-      );
-
-      /* Shoot a ray */
-      state.reclevel = scene->reclimit;
-      state.ior = 1.0;
-      state.adc_value = dmnsn_white;
-      dmnsn_color color = dmnsn_ray_shoot(&state, ray);
-
-      dmnsn_canvas_set_pixel(scene->canvas, x, y, color);
-    }
-
-    dmnsn_future_increment(future);
-  }
-
-  return 0;
-}
-
-/** Calculate the background color. */
-static dmnsn_color
-dmnsn_trace_background(const dmnsn_rtstate *state, dmnsn_line ray)
-{
-  dmnsn_pigment *background = state->scene->background;
-  if (state->scene->quality & DMNSN_RENDER_PIGMENT) {
-    return dmnsn_pigment_evaluate(background, dmnsn_vector_normalized(ray.n));
-  } else {
-    return background->quick_color;
-  }
-}
-
-/** Calculate the base pigment at the intersection. */
-static void
-dmnsn_trace_pigment(dmnsn_rtstate *state)
-{
-  dmnsn_pigment *pigment = state->texture->pigment;
-  if (state->scene->quality & DMNSN_RENDER_PIGMENT) {
-    state->pigment = dmnsn_pigment_evaluate(pigment, state->pigment_r);
-  } else {
-    state->pigment = pigment->quick_color;
-  }
-
-  state->diffuse = state->pigment;
-}
-
-/** Get the color of a light ray at an intersection point. */
-static bool
-dmnsn_trace_light_ray(dmnsn_rtstate *state, const dmnsn_light *light,
-                      dmnsn_color *color)
-{
-  /** @todo: Start at the light source */
-  dmnsn_line shadow_ray = dmnsn_new_line(
-    state->r,
-    light->direction_fn(light, state->r)
-  );
-  state->light = dmnsn_vector_normalized(shadow_ray.n);
-  /* Add epsilon to avoid hitting ourselves with the shadow ray */
-  shadow_ray = dmnsn_line_add_epsilon(shadow_ray);
-
-  /* Check if we're casting a shadow on ourself */
-  if (dmnsn_vector_dot(shadow_ray.n, state->intersection->normal)
-      * dmnsn_vector_dot(state->viewer, state->intersection->normal) < 0.0)
-  {
-    return false;
-  }
-
-  *color = light->illumination_fn(light, state->r);
-
-  /* Test for shadow ray intersections */
-  unsigned int reclevel = state->reclevel;
-  while (reclevel-- > 0
-         && dmnsn_color_intensity(*color) >= state->scene->adc_bailout)
-  {
-    dmnsn_intersection shadow_caster;
-    bool shadow_was_cast = dmnsn_prtree_intersection(state->prtree, shadow_ray,
-                                                     &shadow_caster, false);
-
-    if (!shadow_was_cast || !light->shadow_fn(light, shadow_caster.t)) {
-      return true;
-    }
-
-    /* Handle transparency */
-    if (state->scene->quality & DMNSN_RENDER_TRANSPARENCY) {
-      dmnsn_rtstate shadow_state = *state;
-      dmnsn_rtstate_initialize(&shadow_state, &shadow_caster);
-      dmnsn_trace_pigment(&shadow_state);
-
-      if (shadow_state.pigment.trans >= dmnsn_epsilon) {
-        /* Reflect the light */
-        const dmnsn_reflection *reflection =
-          shadow_state.texture->finish.reflection;
-        if ((state->scene->quality & DMNSN_RENDER_REFLECTION) && reflection) {
-          dmnsn_color reflected = reflection->reflection_fn(
-            reflection, *color, shadow_state.pigment, shadow_state.reflected,
-            shadow_state.intersection->normal
-          );
-          *color = dmnsn_color_sub(*color, reflected);
-        }
-
-        /* Filter the light */
-        *color = dmnsn_filter_light(*color, shadow_state.pigment);
-        shadow_ray.x0 = dmnsn_line_point(shadow_ray, shadow_caster.t);
-        shadow_ray.n  = light->direction_fn(light, shadow_ray.x0);
-        shadow_ray = dmnsn_line_add_epsilon(shadow_ray);
-        continue;
-      }
-    }
-
-    break;
-  }
-
-  return false;
-}
-
-/** Handle light, shadow, and shading. */
-static void
-dmnsn_trace_lighting(dmnsn_rtstate *state)
-{
-  /* The ambient color */
-  state->diffuse = dmnsn_black;
-
-  const dmnsn_finish *finish = &state->texture->finish;
-  if (finish->ambient) {
-    state->diffuse =
-      finish->ambient->ambient_fn(finish->ambient, state->pigment);
-  }
-
-  /* Iterate over each light */
-  DMNSN_ARRAY_FOREACH (dmnsn_light **, light, state->scene->lights) {
-    dmnsn_color light_color;
-    if (dmnsn_trace_light_ray(state, *light, &light_color)) {
-      if (state->scene->quality & DMNSN_RENDER_FINISH) {
-        /* Get this light's specular contribution to the object */
-        dmnsn_color specular = dmnsn_black;
-        if (finish->specular) {
-          specular = finish->specular->specular_fn(
-            finish->specular, light_color, state->pigment, state->light,
-            state->intersection->normal, state->viewer
-          );
-          light_color = dmnsn_color_sub(light_color, specular);
-        }
-
-        /* Reflect the light */
-        const dmnsn_reflection *reflection = state->texture->finish.reflection;
-        if ((state->scene->quality & DMNSN_RENDER_REFLECTION) && reflection) {
-          dmnsn_color reflected = reflection->reflection_fn(
-            reflection, light_color, state->pigment, state->reflected,
-            state->intersection->normal
-          );
-          light_color = dmnsn_color_sub(light_color, reflected);
-        }
-
-        /* Get this light's diffuse contribution to the object */
-        dmnsn_color diffuse = dmnsn_black;
-        if (finish->diffuse) {
-          diffuse = finish->diffuse->diffuse_fn(
-            finish->diffuse, light_color, state->pigment, state->light,
-            state->intersection->normal
-          );
-        }
-
-        state->diffuse = dmnsn_color_add(diffuse, state->diffuse);
-        state->additional = dmnsn_color_add(specular, state->additional);
-      } else {
-        state->diffuse = state->pigment;
-        state->diffuse.trans  = 0.0;
-        state->diffuse.filter = 0.0;
-      }
-    }
-  }
-}
-
-/** Trace a reflected ray. */
-static dmnsn_color
-dmnsn_trace_reflection(const dmnsn_rtstate *state)
-{
-  dmnsn_color reflected = dmnsn_black;
-
-  const dmnsn_reflection *reflection = state->texture->finish.reflection;
-  if (reflection) {
-    dmnsn_line refl_ray = dmnsn_new_line(state->r, state->reflected);
-    refl_ray = dmnsn_line_add_epsilon(refl_ray);
-
-    dmnsn_rtstate recursive_state = *state;
-
-    /* Calculate ADC value */
-    recursive_state.adc_value = reflection->reflection_fn(
-      reflection, state->adc_value, state->pigment, state->reflected,
-      state->intersection->normal
-    );
-
-    /* Shoot the reflected ray */
-    dmnsn_color rec = dmnsn_ray_shoot(&recursive_state, refl_ray);
-    reflected = reflection->reflection_fn(
-      reflection, rec, state->pigment, state->reflected,
-      state->intersection->normal
-    );
-    reflected.trans  = 0.0;
-    reflected.filter = 0.0;
-  }
-
-  return reflected;
-}
-
-/** Handle transparency - must be called last to work correctly. */
-static void
-dmnsn_trace_transparency(dmnsn_rtstate *state)
-{
-  if (state->pigment.trans >= dmnsn_epsilon) {
-    dmnsn_line trans_ray = dmnsn_new_line(state->r, state->intersection->ray.n);
-    trans_ray = dmnsn_line_add_epsilon(trans_ray);
-
-    dmnsn_vector r = dmnsn_vector_normalized(trans_ray.n);
-    dmnsn_vector n = state->intersection->normal;
-
-    dmnsn_rtstate recursive_state = *state;
-
-    /* Calculate new refractive index */
-    if (dmnsn_vector_dot(r, n) < 0.0) {
-      /* We are entering an object */
-      recursive_state.ior = state->interior->ior;
-      recursive_state.parent = state;
-    } else {
-      /* We are leaving an object */
-      recursive_state.ior = state->parent ? state->parent->ior : 1.0;
-      recursive_state.parent = state->parent ? state->parent->parent : NULL;
-    }
-
-    /* Calculate transmitted ray direction */
-    double iorr = state->ior/recursive_state.ior; /* ior ratio */
-    double c1 = -dmnsn_vector_dot(r, n);
-    double c2 = 1.0 - iorr*iorr*(1.0 - c1*c1);
-    if (c2 <= 0.0) {
-      /* Total internal reflection */
-      return;
-    }
-    c2 = sqrt(c2);
-    if (c1 >= 0.0) {
-      trans_ray.n = dmnsn_vector_add(
-        dmnsn_vector_mul(iorr, r),
-        dmnsn_vector_mul(iorr*c1 - c2, n)
-      );
-    } else {
-      trans_ray.n = dmnsn_vector_add(
-        dmnsn_vector_mul(iorr, r),
-        dmnsn_vector_mul(iorr*c1 + c2, n)
-      );
-    }
-
-    /* Calculate ADC value */
-    recursive_state.adc_value =
-      dmnsn_filter_light(state->adc_value, state->pigment);
-
-    /* Shoot the transmitted ray */
-    dmnsn_color rec = dmnsn_ray_shoot(&recursive_state, trans_ray);
-    dmnsn_color filtered = dmnsn_filter_light(rec, state->pigment);
-
-    /* Conserve energy */
-    const dmnsn_reflection *reflection = state->texture->finish.reflection;
-    if ((state->scene->quality & DMNSN_RENDER_REFLECTION) && reflection) {
-      dmnsn_color reflected = reflection->reflection_fn(
-        reflection, filtered, state->pigment, state->reflected,
-        state->intersection->normal
-      );
-      filtered = dmnsn_color_sub(filtered, reflected);
-    }
-
-    state->diffuse.filter = state->pigment.filter;
-    state->diffuse.trans  = state->pigment.trans;
-    state->diffuse = dmnsn_apply_transparency(filtered, state->diffuse);
-  }
-}
-
-/* Shoot a ray, and calculate the color */
-static dmnsn_color
-dmnsn_ray_shoot(dmnsn_rtstate *state, dmnsn_line ray)
-{
-  if (state->reclevel == 0
-      || dmnsn_color_intensity(state->adc_value) < state->scene->adc_bailout)
-  {
-    return dmnsn_black;
-  }
-
-  --state->reclevel;
-
-  dmnsn_intersection intersection;
-  bool reset = state->reclevel == state->scene->reclimit - 1;
-  if (dmnsn_prtree_intersection(state->prtree, ray, &intersection, reset)) {
-    /* Found an intersection */
-    dmnsn_rtstate_initialize(state, &intersection);
-
-    /* Pigment */
-    dmnsn_trace_pigment(state);
-
-    /* Finishes and shadows */
-    if (state->scene->quality & DMNSN_RENDER_LIGHTS) {
-      dmnsn_trace_lighting(state);
-    }
-
-    /* Reflection */
-    if (state->scene->quality & DMNSN_RENDER_REFLECTION) {
-      state->additional = dmnsn_color_add(
-        dmnsn_trace_reflection(state),
-        state->additional
-      );
-    }
-
-    /* Transparency */
-    if (state->scene->quality & DMNSN_RENDER_TRANSPARENCY) {
-      dmnsn_trace_transparency(state);
-    }
-
-    return dmnsn_color_add(state->diffuse, state->additional);
-  } else {
-    /* No intersection, return the background color */
-    return dmnsn_trace_background(state, ray);
-  }
-}