From e1514fae78052db286738efea00c16a1ce39b355 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C3=ABl=20Lemaire?= <michael@thunderk.net>
Date: Wed, 30 Jan 2013 22:06:29 +0000
Subject: [PATCH] paysages : Fixed bruneton aerial perspective.

git-svn-id: https://subversion.assembla.com/svn/thunderk/paysages@512 b1fd45b6-86a6-48da-8261-f70d1f35bdcc
---
 TODO                               |  2 +-
 lib_paysages/atmosphere/bruneton.c | 28 +++++++++++++++++++++++++---
 lib_paysages/renderer.c            |  2 +-
 3 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/TODO b/TODO
index 835ad29..9351d8f 100644
--- a/TODO
+++ b/TODO
@@ -6,7 +6,7 @@ Technology Preview 2 :
    => Allow camera move and zoom.
 - Get rid of noise dialogs, for simpler settings.
 - Finalize Bruneton's model
-   => Fix artifacts on aerial perspective
+   => Fix artifacts on aerial perspective (mostly when sun is near horizon)
    => Fix blue appearance at night
 - Finalize lighting refactoring
    => Restore water filtering
diff --git a/lib_paysages/atmosphere/bruneton.c b/lib_paysages/atmosphere/bruneton.c
index e20fb88..3f16488 100644
--- a/lib_paysages/atmosphere/bruneton.c
+++ b/lib_paysages/atmosphere/bruneton.c
@@ -1144,6 +1144,7 @@ Color brunetonGetSkyColor(AtmosphereDefinition* definition, Vector3 eye, Vector3
 {
     UNUSED(definition);
 
+    /* TODO Water height ? */
     Vector3 x = {0.0, Rg + (max(eye.y, 0.0) + GROUND_OFFSET) * WORLD_SCALING, 0.0};
     Vector3 v = v3Normalize(direction);
     Vector3 s = v3Normalize(v3Sub(sun_position, x));
@@ -1166,10 +1167,22 @@ Color brunetonGetSkyColor(AtmosphereDefinition* definition, Vector3 eye, Vector3
 Color brunetonApplyAerialPerspective(Renderer* renderer, Vector3 location, Color base)
 {
     Vector3 eye = renderer->camera_location;
-    Vector3 direction = v3Scale(v3Sub(location, eye), WORLD_SCALING);
     Vector3 sun_position = v3Scale(renderer->atmosphere->getSunDirection(renderer), SUN_DISTANCE);
 
-    Vector3 x = {0.0, Rg + (max(eye.y, 0.0) + GROUND_OFFSET) * WORLD_SCALING, 0.0};
+    double yoffset = GROUND_OFFSET - renderer->getWaterHeightInfo(renderer).base_height;
+    eye.y += yoffset;
+    location.y += yoffset;
+    if (eye.y < 0.0)
+    {
+        eye.y = 0.0;
+    }
+    if (location.y < 0.0)
+    {
+        location.y = 0.0;
+    }
+    Vector3 direction = v3Scale(v3Sub(location, eye), WORLD_SCALING);
+
+    Vector3 x = {0.0, Rg + eye.y * WORLD_SCALING, 0.0};
     Vector3 v = v3Normalize(direction);
     Vector3 s = v3Normalize(v3Sub(sun_position, x));
 
@@ -1197,7 +1210,16 @@ void brunetonGetLightingStatus(Renderer* renderer, LightStatus* status, Vector3
     LightDefinition sun, irradiance;
     double muS;
 
-    double r0 = Rg + (max(lightingGetStatusLocation(status).y, 0.0) + GROUND_OFFSET) * WORLD_SCALING;
+    double altitude = lightingGetStatusLocation(status).y;
+
+    double yoffset = GROUND_OFFSET - renderer->getWaterHeightInfo(renderer).base_height;
+    altitude += yoffset;
+    if (altitude < 0.0)
+    {
+        altitude = 0.0;
+    }
+
+    double r0 = Rg + altitude * WORLD_SCALING;
     Vector3 up = {0.0, 1.0, 0.0};
     Vector3 sun_position = v3Scale(renderer->atmosphere->getSunDirection(renderer), SUN_DISTANCE);
     Vector3 x = {0.0, r0, 0.0};
diff --git a/lib_paysages/renderer.c b/lib_paysages/renderer.c
index 48fffbb..a83118d 100644
--- a/lib_paysages/renderer.c
+++ b/lib_paysages/renderer.c
@@ -6,7 +6,7 @@
 #include "scenery.h"
 
 RayCastingResult _RAYCASTING_NULL = {0};
-HeightInfo _WATER_HEIGHT_INFO = {-1000000.0, -1000000.0, -1000000.0};
+HeightInfo _WATER_HEIGHT_INFO = {0.0, 0.0, 0.0};
 
 static void* _renderFirstPass(void* data)
 {