From 6787a9219748575cd63aaadd483f49a4fd83b543 Mon Sep 17 00:00:00 2001 From: Tavian Barnes Date: Sat, 9 Jan 2010 20:38:51 -0500 Subject: Implement reflection. --- libdimension/raytrace.c | 144 +++++++++++++++++++++++++++++++++--------------- 1 file changed, 100 insertions(+), 44 deletions(-) (limited to 'libdimension/raytrace.c') diff --git a/libdimension/raytrace.c b/libdimension/raytrace.c index 2df267f..9cfb904 100644 --- a/libdimension/raytrace.c +++ b/libdimension/raytrace.c @@ -220,6 +220,8 @@ typedef struct dmnsn_raytrace_state { const dmnsn_intersection *intersection; dmnsn_kD_splay_tree *kD_splay_tree; unsigned int level; + + dmnsn_color pigment; } dmnsn_raytrace_state; /* Main helper for dmnsn_raytrace_scene_impl - shoot a ray */ @@ -283,12 +285,9 @@ dmnsn_line_add_epsilon(dmnsn_line l) ); } -static dmnsn_color -dmnsn_raytrace_pigment(const dmnsn_raytrace_state *state) +static const dmnsn_pigment * +dmnsn_raytrace_get_pigment(const dmnsn_raytrace_state *state) { - /* Default to black if there's no texture/pigment */ - dmnsn_color color = dmnsn_black; - /* Use the default texture if given a NULL texture */ const dmnsn_texture *texture = state->intersection->texture ? state->intersection->texture @@ -296,16 +295,42 @@ dmnsn_raytrace_pigment(const dmnsn_raytrace_state *state) if (texture) { /* Use the default pigment if given a NULL pigment */ - const dmnsn_pigment *pigment - = texture->pigment ? texture->pigment - : state->scene->default_texture->pigment; - - if (pigment) { - color = (*pigment->pigment_fn)( - pigment, - dmnsn_line_point(state->intersection->ray, state->intersection->t) - ); - } + return texture->pigment ? texture->pigment + : state->scene->default_texture->pigment; + } else { + return NULL; + } +} + +static const dmnsn_finish * +dmnsn_raytrace_get_finish(const dmnsn_raytrace_state *state) +{ + /* Use the default texture if given a NULL texture */ + const dmnsn_texture *texture + = state->intersection->texture ? state->intersection->texture + : state->scene->default_texture; + + if (texture) { + /* Use the default finish if given a NULL finish */ + return texture->finish ? texture->finish + : state->scene->default_texture->finish; + } else { + return NULL; + } +} + +static dmnsn_color +dmnsn_raytrace_pigment(const dmnsn_raytrace_state *state) +{ + /* Default to black if there's no texture/pigment */ + dmnsn_color color = dmnsn_black; + + const dmnsn_pigment *pigment = dmnsn_raytrace_get_pigment(state); + if (pigment) { + color = (*pigment->pigment_fn)( + pigment, + dmnsn_line_point(state->intersection->ray, state->intersection->t) + ); } return color; @@ -366,24 +391,14 @@ dmnsn_raytrace_light_ray(const dmnsn_raytrace_state *state, } static dmnsn_color -dmnsn_raytrace_lighting(const dmnsn_raytrace_state *state, dmnsn_color color) +dmnsn_raytrace_lighting(const dmnsn_raytrace_state *state) { - /* Use the default texture if given a NULL texture */ - const dmnsn_texture *texture - = state->intersection->texture ? state->intersection->texture - : state->scene->default_texture; - - const dmnsn_finish *finish = NULL; - if (texture) { - /* Use the default finish if given a NULL finish */ - finish = texture->finish ? texture->finish - : state->scene->default_texture->finish; - } + const dmnsn_finish *finish = dmnsn_raytrace_get_finish(state); /* The illuminated color */ dmnsn_color illum = dmnsn_black; if (finish && finish->ambient_fn) - illum = (*finish->ambient_fn)(finish, color); + illum = (*finish->ambient_fn)(finish, state->pigment); dmnsn_vector x0 = dmnsn_line_point(state->intersection->ray, state->intersection->t); @@ -410,11 +425,11 @@ dmnsn_raytrace_lighting(const dmnsn_raytrace_state *state, dmnsn_color color) /* Get this light's color contribution to the object */ dmnsn_color contrib = (*finish->finish_fn)(finish, - light_color, color, + light_color, state->pigment, ray, normal, viewer); illum = dmnsn_color_add(contrib, illum); } else { - illum = color; + illum = state->pigment; } } } @@ -422,13 +437,47 @@ dmnsn_raytrace_lighting(const dmnsn_raytrace_state *state, dmnsn_color color) return illum; } +static dmnsn_color +dmnsn_raytrace_reflection(const dmnsn_raytrace_state *state, dmnsn_color color) +{ + const dmnsn_finish *finish = dmnsn_raytrace_get_finish(state); + dmnsn_color refl = color; + + if (finish && finish->reflection_fn) { + dmnsn_vector normal = state->intersection->normal; + dmnsn_vector viewer = dmnsn_vector_normalize( + dmnsn_vector_negate(state->intersection->ray.n) + ); + dmnsn_vector ray = dmnsn_vector_sub( + dmnsn_vector_mul(2*dmnsn_vector_dot(viewer, normal), normal), + viewer + ); + + dmnsn_line refl_ray = dmnsn_new_line( + dmnsn_line_point(state->intersection->ray, state->intersection->t), + ray + ); + refl_ray = dmnsn_line_add_epsilon(refl_ray); + + dmnsn_raytrace_state recursive_state = *state; + dmnsn_color rec = dmnsn_raytrace_shoot(&recursive_state, refl_ray); + refl = dmnsn_color_add( + (*finish->reflection_fn)(finish, rec, state->pigment, ray, normal), + refl + ); + } + + return refl; +} + static dmnsn_color dmnsn_raytrace_translucency(const dmnsn_raytrace_state *state, - dmnsn_color color, dmnsn_color pigment) + dmnsn_color color) { dmnsn_color trans = color; - if (pigment.filter || pigment.trans) { - trans = dmnsn_color_mul(1.0 - pigment.filter - pigment.trans, color); + if (state->pigment.filter || state->pigment.trans) { + trans = dmnsn_color_mul(1.0 - state->pigment.filter - state->pigment.trans, + color); dmnsn_line trans_ray = dmnsn_new_line( dmnsn_line_point(state->intersection->ray, state->intersection->t), @@ -438,7 +487,7 @@ dmnsn_raytrace_translucency(const dmnsn_raytrace_state *state, dmnsn_raytrace_state recursive_state = *state; dmnsn_color rec = dmnsn_raytrace_shoot(&recursive_state, trans_ray); - dmnsn_color filtered = dmnsn_color_filter(rec, pigment); + dmnsn_color filtered = dmnsn_color_filter(rec, state->pigment); trans = dmnsn_color_add(trans, filtered); } return trans; @@ -459,26 +508,33 @@ dmnsn_raytrace_shoot(dmnsn_raytrace_state *state, dmnsn_line ray) if (intersection) { state->intersection = intersection; - /* Get the pigment of the object */ - dmnsn_color pigment = dmnsn_black; + /* Pigment */ + state->pigment = dmnsn_black; if (state->scene->quality & DMNSN_RENDER_PIGMENT) { - pigment = dmnsn_raytrace_pigment(state); + state->pigment = dmnsn_raytrace_pigment(state); } - color = pigment; + color = state->pigment; - /* Account for finishes and shadows */ - dmnsn_color illum = pigment; + /* Finishes and shadows */ + dmnsn_color illum = color; if (state->scene->quality & DMNSN_RENDER_LIGHTS) { - illum = dmnsn_raytrace_lighting(state, illum); + illum = dmnsn_raytrace_lighting(state); } color = illum; - /* Account for translucency */ - dmnsn_color trans = illum; + /* Reflection */ + dmnsn_color refl = illum; + if (state->scene->quality & DMNSN_RENDER_REFLECTION) { + refl = dmnsn_raytrace_reflection(state, refl); + } + color = refl; + + /* Translucency */ + dmnsn_color trans = color; trans.filter = 0.0; trans.trans = 0.0; if (state->scene->quality & DMNSN_RENDER_TRANSLUCENCY) { - trans = dmnsn_raytrace_translucency(state, trans, pigment); + trans = dmnsn_raytrace_translucency(state, trans); } color = trans; -- cgit v1.2.3