From 41caa6030dd8a1d1770be94a0e413ee67af138d0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miloslav=20=C4=8C=C3=AD=C5=BE?= <tastyfish@seznam.cz>
Date: Fri, 28 Jun 2019 01:25:32 +0200
Subject: [PATCH] Fix index overflows

---
 programs/highPoly.c | 14 ++++++++------
 small3dlib.h        |  6 +++---
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/programs/highPoly.c b/programs/highPoly.c
index 1082423..32fde45 100644
--- a/programs/highPoly.c
+++ b/programs/highPoly.c
@@ -82,19 +82,21 @@ void drawPixel(S3L_PixelInfo *p)
 
   S3L_normalizeVec3(&normal);
 
-  uint8_t shading = 
-    S3L_clamp((S3L_dotProductVec3(normal,toLight) + S3L_FRACTIONS_PER_UNIT) / 4,0,255);
+  S3L_Unit shading = 
+    (S3L_dotProductVec3(normal,toLight) + S3L_FRACTIONS_PER_UNIT) / 2;
+
+  shading = S3L_interpolate(shading,0,p->depth,32 * S3L_FRACTIONS_PER_UNIT);
 
   int index = (p->y * S3L_RESOLUTION_X + p->x) * 3;
 
-  frameBuffer[index] = shading;
-  frameBuffer[index + 1] = shading; 
-  frameBuffer[index + 2] = shading; 
+  frameBuffer[index] = S3L_clamp(S3L_interpolateByUnitFrom0(200,shading),0,255);
+  frameBuffer[index + 1] = S3L_clamp(S3L_interpolateByUnitFrom0(255,shading),0,255);
+  frameBuffer[index + 2] = S3L_clamp(S3L_interpolateByUnitFrom0(150,shading),0,255); 
 }
 
 int main()
 {
-  S3L_setVec4(&toLight,10,10,10,0);
+  S3L_setVec4(&toLight,10,-10,-10,0);
 
   S3L_normalizeVec3(&toLight);
 
diff --git a/small3dlib.h b/small3dlib.h
index 38f7710..79e6ea6 100644
--- a/small3dlib.h
+++ b/small3dlib.h
@@ -982,7 +982,7 @@ void S3L_getIndexedTriangleValues(
   S3L_Vec4 *v1,
   S3L_Vec4 *v2)
 {
-  S3L_Index i0, i1;
+  uint32_t i0, i1;
   S3L_Unit *value;
 
   i0 = triangleIndex * 3;
@@ -1046,7 +1046,7 @@ void S3L_computeModelNormals(S3L_Model3D model, S3L_Unit *dst,
         (model.triangles[j + 2] == i))
       {    
         S3L_Vec4 t0, t1, t2;
-        S3L_Index vIndex;
+        uint32_t vIndex;
 
         #define getVertex(n)\
           vIndex = model.triangles[j + n] * 3;\
@@ -2437,7 +2437,7 @@ void _S3L_projectVertex(
   S3L_Vec4 *result,
   S3L_Unit focalLength)
 {
-  S3L_Index vertexIndex = model->triangles[triangleIndex * 3 + vertex] * 3;
+  uint32_t vertexIndex = model->triangles[triangleIndex * 3 + vertex] * 3;
 
   result->x = model->vertices[vertexIndex];
   result->y = model->vertices[vertexIndex + 1];