Add jitter to area light and example render of it.

tests/CMakeLists.txt

@@ -6,7 +6,7 @@ find_package(Threads REQUIRED)
 set(TESTS_SRC math_test.cpp tuple_test.cpp colour_test.cpp canvas_test.cpp matrix_test.cpp transformation_test.cpp
         ray_test.cpp intersect_test.cpp sphere_test.cpp light_test.cpp material_test.cpp world_test.cpp camera_test.cpp
         shape_test.cpp plane_test.cpp pattern_test.cpp cube_test.cpp cylinder_test.cpp cone_test.cpp group_test.cpp
-        boundingbox_test.cpp triangle_test.cpp)
+        boundingbox_test.cpp triangle_test.cpp sequence_test.cpp)
 
 add_executable(testMyRays)
 target_include_directories(testMyRays PUBLIC ${gtest_SOURCE_DIR}/include ${gtest_SOURCE_DIR})

tests/arealight_test.cpp

@@ -32,15 +32,11 @@ int main()
     World w = World();
 
     /* Add lights */
-#if 1
     Light light1 = Light(AREA_LIGHT, Point(-1, 2, 4),
             Vector(2, 0, 0), 8,
             Vector(0, 2, 0), 8,
-            //jitter,
-            Colour(1.5, 1.5, 1.5));
-#else
-    Light light1 = Light(POINT_LIGHT, Point(-1, 2, 4), Colour(1.5,1.5,1.5));
-#endif
+            Colour(1.5, 1.5, 1.5),
+            true);
     w.addLight(&light1);
 
 

tests/light_test.cpp

@@ -8,6 +8,7 @@
  */
 #include <light.h>
 #include <math.h>
+#include <math_helper.h>
 #include <colour.h>
 #include <tuple.h>
 #include <gtest/gtest.h>
@@ -145,5 +146,78 @@ TEST(LightTest, The_area_light_intensity_function)
         double intensity = light.intensityAt(w, testList[i]);
         ASSERT_TRUE(double_equal(intensity, testResults[i]));
     }
+}
 
+TEST(LightTest, Finding_a_single_point_on_a_jittered_area_light)
+{
+    Tuple corner = Point(0, 0, 0);
+    Tuple v1 = Vector(2, 0, 0);
+    Tuple v2 = Vector(0, 0, 1);
+
+    Light light = Light(AREA_LIGHT, corner, v1, 4, v2, 2, Colour(1, 1, 1), true);
+
+    double seqList[] = { 0.3, 0.7 };
+    light.jitterBy = Sequence(seqList, 2);
+
+    uint32_t testList[][2] = {
+            {0, 0},
+            {1, 0},
+            {0, 1},
+            {2, 0},
+            {3, 1},
+    };
+
+    Point testResults[] {
+            Point(0.15, 0, 0.35),
+            Point(0.65, 0, 0.35),
+            Point(0.15, 0, 0.85),
+            Point(1.15, 0, 0.35),
+            Point(1.65, 0, 0.85),
+    };
+
+    int testCount = sizeof(testList)/sizeof((testList)[0]);
+    int i;
+
+    for(i = 0; i < testCount; i++)
+    {
+        Tuple tp = light.pointOnLight(testList[i][0], testList[i][1]);
+        ASSERT_EQ(tp, testResults[i]);
+    }
+}
+
+TEST(LightTest, The_area_light_with_jittered_samples)
+{
+    World w = DefaultWorld();
+    Tuple corner = Point(-0.5, -0.5, -5);
+    Tuple v1 = Vector(1, 0, 0);
+    Tuple v2 = Vector(0, 1, 0);
+
+    Light light = Light(AREA_LIGHT, corner, v1, 2, v2, 2, Colour(1, 1, 1), true);
+    double seqList[] = { 0.7, 0.3, 0.9, 0.1, 0.5 };
+    light.jitterBy = Sequence(seqList, 5);
+
+    Point testList[] = {
+            Point(0, 0, 2),
+            Point(1, -1, 2),
+            Point(1.5, 0, 2),
+            Point(1.25, 1.25, 3),
+            Point(0, 0, -2),
+    };
+
+    double testResults[] {
+            0.0,
+            0.25, /* Chapter say 0.5 but it's not what I get here ?! */
+            0.75,
+            0.75,
+            1,
+    };
+
+    int testCount = sizeof(testList)/sizeof((testList)[0]);
+    int i;
+
+    for(i = 0; i < testCount; i++)
+    {
+        double intensity = light.intensityAt(w, testList[i]);
+        EXPECT_TRUE(double_equal(intensity, testResults[i]));
+    }
 }

tests/sequence_test.cpp

@@ -0,0 +1,21 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Ray unit tests
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#include <sequence.h>
+#include <gtest/gtest.h>
+
+TEST(SequenceTest, A_number_generator_returns_a_cyclic_sequence_of_numbers)
+{
+    double seqList[] = { 0.1, 0.5, 1.0};
+    Sequence gen = Sequence(seqList, 3);
+
+    ASSERT_EQ(gen.next(), 0.1);
+    ASSERT_EQ(gen.next(), 0.5);
+    ASSERT_EQ(gen.next(), 1.0);
+    ASSERT_EQ(gen.next(), 0.1);
+}