From 6ac1e899f8dc5bd06ac480e4c4e17f8cda8ed35f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C3=ABl=20Lemaire?= <michael@thunderk.net>
Date: Thu, 17 Mar 2016 19:56:57 +0100
Subject: [PATCH] Added terrain ray marching visual testing

---
 src/interface/commandline/tests.cpp | 63 +++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

diff --git a/src/interface/commandline/tests.cpp b/src/interface/commandline/tests.cpp
index 4ef7e7b..37dca84 100644
--- a/src/interface/commandline/tests.cpp
+++ b/src/interface/commandline/tests.cpp
@@ -37,6 +37,7 @@
 #include "NoiseFunctionSimplex.h"
 #include "Zone.h"
 #include "MaterialNode.h"
+#include "TerrainRayWalker.h"
 
 #include <cmath>
 #include <sstream>
@@ -581,12 +582,72 @@ static void testCanvasAliasing() {
     }
 }
 
+static void testTerrainRayMarching() {
+    int width = 2000;
+    int height = 600;
+    Texture2D result(width, height);
+    result.fill(COLOR_WHITE);
+
+    Scenery scenery;
+    SoftwareRenderer renderer(&scenery);
+
+    auto terrain = scenery.getTerrain();
+    terrain->propWaterHeight()->setValue(0.0);
+    terrain->propHeightNoise()->setConfig(to_double(height), 1.0, 0.5, 0.1);
+
+    TextureLayerDefinition disp(NULL, "disp");
+    disp.propDisplacementNoise()->setConfig(to_double(height) * 0.4);
+    terrain->propDisplacements()->addLayer(disp);
+
+    terrain->validate();
+
+    int multisample = 8;
+
+    // Draw terrain shape
+    for (int x = 0; x < width * multisample; x++) {
+        double altitude = terrain->getInterpolatedHeight(to_double(x) / to_double(multisample), 0.0, true, false);
+        int y = height / 2 + round_to_int(altitude);
+        if (y >= 0 && y < height) {
+            result.setPixel(x / multisample, y, COLOR_GREY);
+        }
+
+        Vector3 displaced = renderer.getTerrainRenderer()->getDisplaced(to_double(x) / to_double(multisample), 0.0, true);
+        int hx = round_to_int(displaced.x);
+        int hy = height / 2 + round_to_int(displaced.y);
+        if (hx >= 0 && hx < width && hy >= 0 && hy < height) {
+            result.setPixel(hx, hy, COLOR_BLACK);
+        }
+
+        result.setPixel(x / multisample, height / 2 + round_to_int(terrain->propWaterHeight()->getValue()), COLOR_BLUE);
+    }
+
+    // Draw ray marcher iterations
+    TerrainRayWalker walker(&renderer);
+    walker.setQuality(1.0, 0.1, 5.0, 1.0, to_double(height), 0.1);
+    walker.update();
+    double offset = 0.0;
+    Vector3 direction = Vector3(offset, -1.0, 0.0).normalize();
+    for (int x = 0; x < width * multisample; x++) {
+        TerrainRayWalker::TerrainHitResult hit;
+        double max_height = terrain->getHeightInfo().max_height;
+        walker.startWalking(Vector3(to_double(x) / to_double(multisample) - to_double(max_height) * offset, to_double(max_height), 0.0), direction, 0.0, hit);
+        int hx = round_to_int(hit.hit_location.x);
+        int hy = height / 2 + round_to_int(hit.hit_location.y);
+        if (hx >= 0 && hx < width && hy >= 0 && hy < height) {
+            result.setPixel(hx, hy, COLOR_RED);
+        }
+    }
+
+    result.saveToFile(getFileName("terrain_ray_marching"));
+}
+
 void runTestSuite() {
     testNoise();
     testCanvasAliasing();
     testTextures();
     testGodRays();
     testCelestialBodies();
+    testTerrainRayMarching();
     testNearFrustum();
     testCloudsLighting();
     testCloudModels();
@@ -597,4 +658,6 @@ void runTestSuite() {
     testGroundShadowQuality();
     testCloudQuality();
     testAtmosphereBruneton();
+
+    cout << "Done." << endl;
 }