mirror of
https://github.com/Mercury-Language/mercury.git
synced 2025-12-15 22:03:26 +00:00
cc5f924841
Estimated hours taken: 1 compiler/pd_util.m: Fix a loop in inst_MSG caused by not keeping track of the set of already expanded insts. tests/valid/deforest_loop.m: Regression test.
88 lines
2.4 KiB
Mathematica
88 lines
2.4 KiB
Mathematica
% This test case triggered an infinite loop in deforestation
|
|
% in the compiler of 3/11/1998.
|
|
:- module deforest_loop.
|
|
:- interface.
|
|
|
|
:- import_module float.
|
|
|
|
% Lights are modelled as points.
|
|
:- type light
|
|
---> light(
|
|
float, % Power in range [0.0, 1.0].
|
|
vec % Position of light.
|
|
).
|
|
|
|
:- type attributes == int.
|
|
|
|
:- pred shade(scene, ray, ray, attributes, colour).
|
|
:- mode shade(in(scene), in, in, in, out) is det.
|
|
|
|
:- type vec == int.
|
|
|
|
:- inst scene
|
|
---> scene(
|
|
list_skel(object),
|
|
ground,
|
|
ground,
|
|
ground,
|
|
ground,
|
|
ground,
|
|
ground
|
|
).
|
|
|
|
:- type scene
|
|
---> scene(
|
|
list(object), % objects
|
|
list(light), % light sources
|
|
float, % ambient illumination
|
|
float, % coefficient of specular reflection
|
|
float, % exponent of specular reflection
|
|
float, % focal length of pin-hole camera
|
|
colour % background colour
|
|
).
|
|
|
|
:- type colour ---> rgb(float, float, float).
|
|
:- type ray == int.
|
|
|
|
:- type object == pred(int, int).
|
|
:- inst object = (pred(in, out) is nondet).
|
|
|
|
:- implementation.
|
|
|
|
:- import_module list, math.
|
|
|
|
shade(Scene, Ray, Intersection, Attributes, Colour) :-
|
|
Colour0 = colour(Attributes),
|
|
Ambient = scale(ambient(Scene), Colour0),
|
|
list__map(shade_from_light(Scene, Ray, Intersection, Colour0),
|
|
lights(Scene), Colours),
|
|
list__foldl(add_colours, Colours, Ambient, Colour).
|
|
|
|
:- pred shade_from_light(scene, ray, ray, colour, light, colour).
|
|
:- mode shade_from_light(in(scene), in, in, in, in, out) is det.
|
|
|
|
:- external(shade_from_light/6).
|
|
|
|
:- func colour(attributes) = colour.
|
|
:- external(colour/1).
|
|
|
|
:- func scale(float, colour) = colour.
|
|
scale(F, rgb(R, G, B)) = rgb(range(F * R), range(F * G), range(F * B)).
|
|
|
|
:- func ambient(scene::in(scene)) = (float::out) is det.
|
|
:- external(ambient/1).
|
|
|
|
:- func lights(scene::in(scene)) = (list(light)::out) is det.
|
|
:- external(lights/1).
|
|
|
|
:- pred add_colours(colour::in, colour::in, colour::out) is det.
|
|
add_colours(C0, C1, C0 + C1).
|
|
|
|
:- func '+'(colour, colour) = colour.
|
|
rgb(Ra, Ga, Ba) + rgb(Rb, Gb, Bb) =
|
|
rgb(range(Ra + Rb), range(Ga + Gb), range(Ba + Bb)).
|
|
|
|
:- func range(float) = float.
|
|
:- external(range/1).
|
|
|