From f46f08b8393d79d3ad33280c50523a55a24cdd9f Mon Sep 17 00:00:00 2001
From: baixiao <34674721+baixiaohub@users.noreply.github.com>
Date: Mon, 7 Feb 2022 00:17:05 +0800
Subject: [PATCH] fix sphere and cylinder picking. (#158)

Encoded picking color pass by vertex attribute would be used by raster interpolation, make decoded picking id may not be the precise value passed in,
and this line of debug check may fail:
https://github.com/nmwsharp/polyscope/blob/master/include/polyscope/pick.ipp#L38
---
 src/render/opengl/shaders/cylinder_shaders.cpp | 12 ++++++------
 src/render/opengl/shaders/sphere_shaders.cpp   |  4 ++--
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/render/opengl/shaders/cylinder_shaders.cpp b/src/render/opengl/shaders/cylinder_shaders.cpp
index 33d6d7ac..663a8b6c 100644
--- a/src/render/opengl/shaders/cylinder_shaders.cpp
+++ b/src/render/opengl/shaders/cylinder_shaders.cpp
@@ -384,9 +384,9 @@ const ShaderReplacementRule CYLINDER_PROPAGATE_PICK (
           in vec3 a_colorTailToGeom[];
           in vec3 a_colorTipToGeom[];
           in vec3 a_colorEdgeToGeom[];
-          out vec3 a_colorTailToFrag;
-          out vec3 a_colorTipToFrag;
-          out vec3 a_colorEdgeToFrag;
+          flat out vec3 a_colorTailToFrag;
+          flat out vec3 a_colorTipToFrag;
+          flat out vec3 a_colorEdgeToFrag;
         )"},
       {"GEOM_PER_EMIT", R"(
           a_colorTailToFrag = a_colorTailToGeom[0]; 
@@ -394,9 +394,9 @@ const ShaderReplacementRule CYLINDER_PROPAGATE_PICK (
           a_colorEdgeToFrag = a_colorEdgeToGeom[0]; 
         )"},
       {"FRAG_DECLARATIONS", R"(
-          in vec3 a_colorTailToFrag;
-          in vec3 a_colorTipToFrag;
-          in vec3 a_colorEdgeToFrag;
+          flat in vec3 a_colorTailToFrag;
+          flat in vec3 a_colorTipToFrag;
+          flat in vec3 a_colorEdgeToFrag;
           float length2(vec3 x);
         )"},
       {"GENERATE_SHADE_VALUE", R"(
diff --git a/src/render/opengl/shaders/sphere_shaders.cpp b/src/render/opengl/shaders/sphere_shaders.cpp
index 9fb75149..42d89184 100644
--- a/src/render/opengl/shaders/sphere_shaders.cpp
+++ b/src/render/opengl/shaders/sphere_shaders.cpp
@@ -425,13 +425,13 @@ const ShaderReplacementRule SPHERE_PROPAGATE_COLOR (
         )"},
       {"GEOM_DECLARATIONS", R"(
           in vec3 a_colorToGeom[];
-          out vec3 a_colorToFrag;
+          flat out vec3 a_colorToFrag;
         )"},
       {"GEOM_PER_EMIT", R"(
           a_colorToFrag = a_colorToGeom[0]; 
         )"},
       {"FRAG_DECLARATIONS", R"(
-          in vec3 a_colorToFrag;
+          flat in vec3 a_colorToFrag;
         )"},
       {"GENERATE_SHADE_VALUE", R"(
           vec3 shadeColor = a_colorToFrag;