From 85cadda3b3d5f67e758e05b40fc5f2266ff45258 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miloslav=20=C4=8C=C3=AD=C5=BE?= <tastyfish@seznam.cz>
Date: Sat, 11 May 2019 19:52:40 +0200
Subject: [PATCH] Fix triangle flicker

---
 s3l.h     |  4 +---
 testSDL.c | 10 ++++++----
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/s3l.h b/s3l.h
index 3ebe16a..067164e 100644
--- a/s3l.h
+++ b/s3l.h
@@ -876,7 +876,7 @@ void _S3L_drawFilledTriangle(
       int16_t bDx = x##b - x##t;\
       int16_t aDy = S3L_nonZero(y##a - y##t);\
       int16_t bDy = S3L_nonZero(y##b - y##t);\
-      if ((aDx << 4) / aDy < (bDx << 4) / bDy)\
+      if ((aDx << 5) / aDy < (bDx << 5) / bDy)\
       {\
         lPointSx = x##a; lPointSy = y##a;\
         rPointSx = x##b; rPointSy = y##b;\
@@ -1175,10 +1175,8 @@ void S3L_drawTriangle(S3L_Vec4 point0, S3L_Vec4 point1, S3L_Vec4 point2,
   const S3L_DrawConfig *config, const S3L_Camera *camera,
   S3L_Index triangleID)
 {
-
   if (config->backfaceCulling != S3L_BACKFACE_CULLING_NONE)
   {
-
     int32_t winding = // determines CW or CCW
       (
         (point1.y - point0.y) * (point2.x - point1.x) - 
diff --git a/testSDL.c b/testSDL.c
index f842bd1..1d620d0 100644
--- a/testSDL.c
+++ b/testSDL.c
@@ -129,11 +129,13 @@ void draw()
 
   clearScreen();
 
-  modelTransform.rotation.z = frame * 0.1;
-  modelTransform.rotation.x = frame * 0.3;
+  uint32_t f = frame;
 
-  modelTransform.translation.x = sin(frame >> 7) * 700;
-  modelTransform.translation.y = sin(frame >> 8) * 600;
+  modelTransform.rotation.z = f * 0.1;
+  modelTransform.rotation.x = f * 0.3;
+
+  modelTransform.translation.x = sin(f >> 7) * 700;
+  modelTransform.translation.y = sin(f >> 8) * 600;
 
   S3L_drawModelIndexed(ver,tri,12,modelTransform,&camera,&conf);