From bd8c3e91814e5ca61aa90cf184caac45f727bd90 Mon Sep 17 00:00:00 2001
From: Mathias Agopian <mathias@google.com>
Date: Tue, 15 Oct 2019 17:22:38 -0700
Subject: [PATCH] don't limit the near plane to ~1mm (#1778)

We were not checking Camera's preconditions properly -- we assumed that
near < 1/1024 meant "near == 0".

Now we check preconditions properly and revert to the same hardcoded
default if they're not met -- doesn't matter what the default is,
it's there only to avoid NaNs and Infs elsewhere -- rendering will
be bogus eitherway.

Fixes #1766
---
 filament/src/Camera.cpp | 33 ++++++++++++++-------------------
 1 file changed, 14 insertions(+), 19 deletions(-)

diff --git a/filament/src/Camera.cpp b/filament/src/Camera.cpp
index 900af0ec4d..6ba5e7f261 100644
--- a/filament/src/Camera.cpp
+++ b/filament/src/Camera.cpp
@@ -22,6 +22,7 @@
 #include "details/Engine.h"
 
 #include <utils/compiler.h>
+#include <utils/Panic.h>
 
 #include <math/scalar.h>
 
@@ -80,25 +81,19 @@ void UTILS_NOINLINE FCamera::setProjection(Camera::Projection projection,
         double bottom, double top,
         double near, double far) noexcept {
 
-    // we silently make sure our preconditions are verified
-    // this is to avoid potential inconsistent state in the renderer later.
-
-    if (UTILS_UNLIKELY(left == right)) {
-        left -= 1;
-        right += 1;
-    }
-
-    if (UTILS_UNLIKELY(bottom == top)) {
-        bottom -= 1;
-        top += 1;
-    }
-
-    if (UTILS_UNLIKELY(projection == Projection::PERSPECTIVE && near < 1.0 / 1024.0)) {
-        near = 1.0 / 1024.0; // about 1mm
-    }
-
-    if (UTILS_UNLIKELY(near == far)) {
-        far += 1;
+    // we make sure our preconditions are verified, using default values,
+    // to avoid inconsistent states in the renderer later.
+    if (UTILS_UNLIKELY(left == right ||
+                       bottom == top ||
+                       (projection == Projection::PERSPECTIVE && (near <= 0 || far <= near)) ||
+                       (projection == Projection::ORTHO && (near == far)))) {
+        PANIC_LOG("Camera preconditions not met. Using default projection.");
+        left = -0.1;
+        right = 0.1;
+        bottom = -0.1;
+        top = 0.1;
+        near = 0.1;
+        far = 100.0;
     }
 
     mat4 p;