From e346c3f8076f2a8e123168e98ecdced98c727b1c Mon Sep 17 00:00:00 2001
From: bjorn <tie.372@gmail.com>
Date: Sun, 28 Mar 2021 10:08:10 -0600
Subject: [PATCH] Fix standard shader precision issues;

- Reduce epsilon
- Also use epsilon in D_GGX
- Reduce shader string length to the minimum required supported length
---
 src/resources/shaders.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/resources/shaders.c b/src/resources/shaders.c
index 26ad6cd8..60817af6 100644
--- a/src/resources/shaders.c
+++ b/src/resources/shaders.c
@@ -184,10 +184,10 @@ const char* lovrStandardVertexShader = ""
 
 const char* lovrStandardFragmentShader = ""
 "#define PI 3.14159265358979 \n"
-"#ifdef GL_ES \n"
-"#define EPS 1e-2 \n"
+"#if defined(GL_ES) && !defined(FLAG_highp) \n"
+"#define EPS 1e-4 \n"
 "#else \n"
-"#define EPS 1e-5 \n"
+"#define EPS 1e-8 \n"
 "#endif \n"
 
 "in vec3 vVertexPositionWorld; \n"
@@ -271,7 +271,7 @@ const char* lovrStandardFragmentShader = ""
 "  float alpha = roughness * roughness; \n"
 "  float alpha2 = alpha * alpha; \n"
 "  float denom = (NoH * NoH) * (alpha2 - 1.) + 1.; \n"
-"  return alpha2 / (PI * denom * denom); \n"
+"  return alpha2 / max(PI * denom * denom, EPS); \n"
 "} \n"
 
 "float G_SmithGGXCorrelated(float NoV, float NoL, float roughness) { \n"
@@ -287,7 +287,7 @@ const char* lovrStandardFragmentShader = ""
 "} \n"
 
 "vec3 E_SphericalHarmonics(vec3 sh[9], vec3 n) { \n"
-"  n = -n; // WHY \n"
+"  n = -n; \n"
 "  return max("
     "sh[0] + "
     "sh[1] * n.y + "
@@ -310,13 +310,13 @@ const char* lovrStandardFragmentShader = ""
 "  return vec2(-1.04, 1.04) * a004 + r.zw; \n"
 "} \n"
 
-"vec3 tonemap_ACES(vec3 color) { \n"
+"vec3 tonemap_ACES(vec3 x) { \n"
 "  float a = 2.51; \n"
 "  float b = 0.03; \n"
 "  float c = 2.43; \n"
 "  float d = 0.59; \n"
 "  float e = 0.14; \n"
-"  return (color * (a * color + b)) / (color * (c * color + d) + e); \n"
+"  return (x * (a * x + b)) / (x * (c * x + d) + e); \n"
 "}";
 
 const char* lovrCubeVertexShader = ""