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authorTavian Barnes <tavianator@gmail.com>2010-01-13 19:32:25 -0500
committerTavian Barnes <tavianator@gmail.com>2010-01-13 19:32:25 -0500
commita7bb99f6d1e01e675a0db831ee7743f1e983dfdb (patch)
tree3b23667538b339cc9d725a3da60c983a7147f1c9 /libdimension
parenta1fae1a38fc3cdb82e379a069fce886cb3fa88ae (diff)
downloaddimension-a7bb99f6d1e01e675a0db831ee7743f1e983dfdb.tar.xz
Implement proper texture overloading.
Diffstat (limited to 'libdimension')
-rw-r--r--libdimension/raytrace.c119
1 files changed, 48 insertions, 71 deletions
diff --git a/libdimension/raytrace.c b/libdimension/raytrace.c
index bb44587..84e170a 100644
--- a/libdimension/raytrace.c
+++ b/libdimension/raytrace.c
@@ -284,55 +284,34 @@ dmnsn_line_add_epsilon(dmnsn_line l)
);
}
-static const dmnsn_pigment *
-dmnsn_raytrace_get_pigment(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 pigment if given a NULL pigment */
- 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;
- }
-}
+/* Determine whether a callback may be called */
+#define DMNSN_TEXTURE_HAS_CALLBACK(state, telem, fn) \
+ ({ \
+ const dmnsn_texture *_itexture = state->intersection->texture; \
+ const dmnsn_texture *_dtexture = state->scene->default_texture; \
+ (_itexture && _itexture->telem && _itexture->telem->fn) \
+ ? 1 \
+ : ((_dtexture && _dtexture->telem && _dtexture->telem->fn) ? 1 : 0); \
+ })
+
+/* Call the appropriate overloaded texture callback */
+#define DMNSN_TEXTURE_CALLBACK(state, telem, fn, def, ...) \
+ ({ \
+ const dmnsn_texture *_itexture = state->intersection->texture; \
+ const dmnsn_texture *_dtexture = state->scene->default_texture; \
+ (_itexture && _itexture->telem && _itexture->telem->fn) \
+ ? (*_itexture->telem->fn)(_itexture->telem, ## __VA_ARGS__) \
+ : ((_dtexture && _dtexture->telem && _dtexture->telem->fn) \
+ ? (*_dtexture->telem->fn)(_dtexture->telem, ## __VA_ARGS__) \
+ : def); \
+ })
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;
+ dmnsn_vector r = dmnsn_line_point(state->intersection->ray,
+ state->intersection->t);
+ return DMNSN_TEXTURE_CALLBACK(state, pigment, pigment_fn, dmnsn_black, r);
}
/* Get the color of a light ray at an intersection point */
@@ -389,12 +368,15 @@ dmnsn_raytrace_light_ray(const dmnsn_raytrace_state *state,
static dmnsn_color
dmnsn_raytrace_lighting(const dmnsn_raytrace_state *state)
{
- 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, state->pigment);
+ dmnsn_color illum = DMNSN_TEXTURE_CALLBACK(state, finish, ambient_fn,
+ dmnsn_black, state->pigment);
+
+ if (!DMNSN_TEXTURE_HAS_CALLBACK(state, finish, diffuse_fn)
+ && !DMNSN_TEXTURE_HAS_CALLBACK(state, finish, specular_fn))
+ {
+ return illum;
+ }
dmnsn_vector x0 = dmnsn_line_point(state->intersection->ray,
state->intersection->t);
@@ -408,9 +390,7 @@ dmnsn_raytrace_lighting(const dmnsn_raytrace_state *state)
dmnsn_color light_color = dmnsn_raytrace_light_ray(state, light);
if (!dmnsn_color_is_black(light_color)) {
- if (state->scene->quality & DMNSN_RENDER_FINISH
- && finish && (finish->diffuse_fn || finish->specular_fn))
- {
+ if (state->scene->quality & DMNSN_RENDER_FINISH) {
dmnsn_vector ray = dmnsn_vector_normalize(
dmnsn_vector_sub(light->x0, x0)
);
@@ -420,19 +400,16 @@ dmnsn_raytrace_lighting(const dmnsn_raytrace_state *state)
);
/* Get this light's color contribution to the object */
- if (finish->diffuse_fn) {
- dmnsn_color diffuse = (*finish->diffuse_fn)(finish, light_color,
- state->pigment,
- ray, normal);
- illum = dmnsn_color_add(diffuse, illum);
- }
-
- if (finish->specular_fn) {
- dmnsn_color specular = (*finish->specular_fn)(finish, light_color,
- state->pigment,
- ray, normal, viewer);
- illum = dmnsn_color_add(specular, illum);
- }
+ dmnsn_color diffuse = DMNSN_TEXTURE_CALLBACK(
+ state, finish, diffuse_fn, dmnsn_black,
+ light_color, state->pigment, ray, normal
+ );
+ dmnsn_color specular = DMNSN_TEXTURE_CALLBACK(
+ state, finish, specular_fn, dmnsn_black,
+ light_color, state->pigment, ray, normal, viewer
+ );
+ illum = dmnsn_color_add(diffuse, illum);
+ illum = dmnsn_color_add(specular, illum);
} else {
illum = state->pigment;
}
@@ -445,10 +422,9 @@ dmnsn_raytrace_lighting(const dmnsn_raytrace_state *state)
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) {
+ if (DMNSN_TEXTURE_HAS_CALLBACK(state, finish, reflection_fn)) {
dmnsn_vector normal = state->intersection->normal;
dmnsn_vector viewer = dmnsn_vector_normalize(
dmnsn_vector_negate(state->intersection->ray.n)
@@ -466,10 +442,11 @@ dmnsn_raytrace_reflection(const dmnsn_raytrace_state *state, dmnsn_color color)
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
+ dmnsn_color contrib = DMNSN_TEXTURE_CALLBACK(
+ state, finish, reflection_fn, dmnsn_black,
+ rec, state->pigment, ray, normal
);
+ refl = dmnsn_color_add(contrib, refl);
}
return refl;