Fix cos function

programs/hqOffline.c

@@ -487,13 +487,13 @@ int main()
 
   char fileName[] = "test00.ppm";
  
-  for (int i = 0; i < 50; ++i)  // render the frames
+  for (int i = 0; i < 100; ++i)  // render the frames
   {
     animateWater();
 
-    scene.camera.transform.translation.x = S3L_sin(i * 5) * 3;
+    scene.camera.transform.translation.x = 2000;
-    scene.camera.transform.translation.y = 5 * S3L_FRACTIONS_PER_UNIT + S3L_cos(i * 6) * 2;
+    scene.camera.transform.translation.y = 3000;
-    scene.camera.transform.translation.z = S3L_cos(i * 4) * 10;
+    scene.camera.transform.translation.z = -S3L_FRACTIONS_PER_UNIT * 8;
 
     S3L_Vec4 target;
     

programs/testSDL.c

@@ -133,12 +133,6 @@ void houseTex(int32_t u, int32_t v, uint8_t *r, uint8_t *g, uint8_t *b)
 
 void drawPixel(S3L_PixelInfo *p)
 {
-
-//setPixel(p->x,p->y,p->triangleIndex,p->triangleIndex,p->triangleIndex);
-setPixel(p->x,p->y,0,0,0);
-
-return;
-
   if (p->x < 0 || p ->x >= S3L_RESOLUTION_X || p->y < 0 || p->y >= S3L_RESOLUTION_Y)
   {
     offScreenPixels++;
@@ -183,13 +177,13 @@ if (p->modelIndex != 0)
     uv0[0],
     uv1[0],
     uv2[0],
-    p->barycentric[0], p->barycentric[1], p->barycentric[2]);
+    p->barycentric);
 
   v = S3L_interpolateBarycentric(
     uv0[1],
     uv1[1],
     uv2[1],
-    p->barycentric[0], p->barycentric[1], p->barycentric[2]);
+    p->barycentric);
 
   uint8_t r,g,b;
   houseTex(
@@ -211,9 +205,9 @@ n2.x = houseNormals[scene.models[p->modelIndex].triangles[p->triangleIndex * 3 +
 n2.y = houseNormals[scene.models[p->modelIndex].triangles[p->triangleIndex * 3 + 2] * 3 + 1];
 n2.z = houseNormals[scene.models[p->modelIndex].triangles[p->triangleIndex * 3 + 2] * 3 + 2];
 
-n.x = S3L_interpolateBarycentric(n0.x,n1.x,n2.x,p->barycentric[0],p->barycentric[1],p->barycentric[2]);
+n.x = S3L_interpolateBarycentric(n0.x,n1.x,n2.x,p->barycentric);
-n.y = S3L_interpolateBarycentric(n0.y,n1.y,n2.y,p->barycentric[0],p->barycentric[1],p->barycentric[2]);
+n.y = S3L_interpolateBarycentric(n0.y,n1.y,n2.y,p->barycentric);
-n.z = S3L_interpolateBarycentric(n0.z,n1.z,n2.z,p->barycentric[0],p->barycentric[1],p->barycentric[2]);
+n.z = S3L_interpolateBarycentric(n0.z,n1.z,n2.z,p->barycentric);
 
 S3L_Vec4 V;
 
@@ -239,13 +233,13 @@ else
     coords[0],
     coords[2],
     coords[4],
-    p->barycentric[0], p->barycentric[1], p->barycentric[2]);
+    p->barycentric);
 
   v = S3L_interpolateBarycentric(
     coords[1],
     coords[3],
     coords[5],
-    p->barycentric[0], p->barycentric[1], p->barycentric[2]);
+    p->barycentric);
 
   uint8_t col = texturePixel(u,v);
   setPixel(p->x,p->y,col,col * 30,(2 - col) * 120);

small3dlib.h

@@ -73,7 +73,8 @@
              |
 
   Rotations use Euler angles and are generally in the extinsic Euler angles in
-  ZXY order (by Z, then by X, then by Y).
+  ZXY order (by Z, then by X, then by Y). Positive rotation about an axis
+  rotates CW (clock-wise) when looking in the direction of the axis.
 
   Coordinates of pixels on screen start typically at the top left, from [0,0].
 
@@ -1178,7 +1179,7 @@ S3L_Unit S3L_asin(S3L_Unit x)
 
 S3L_Unit S3L_cos(S3L_Unit x)
 {
-  return S3L_sin(x - S3L_FRACTIONS_PER_UNIT / 4);
+  return S3L_sin(x + S3L_FRACTIONS_PER_UNIT / 4);
 }
 
 void S3L_correctBarycentricCoords(S3L_Unit barycentric[3])
@@ -1237,6 +1238,10 @@ void S3L_makeRotationMatrixZXY(
   S3L_Unit byZ,
   S3L_Mat4 *m)
 {
+  byX *= -1;
+  byY *= -1;
+  byZ *= -1;
+
   S3L_Unit sx = S3L_sin(byX);
   S3L_Unit sy = S3L_sin(byY);
   S3L_Unit sz = S3L_sin(byZ);
@@ -1344,6 +1349,7 @@ void S3L_initTransoform3D(S3L_Transform3D *t)
   t->scale.x = S3L_FRACTIONS_PER_UNIT;
   t->scale.y = S3L_FRACTIONS_PER_UNIT;
   t->scale.z = S3L_FRACTIONS_PER_UNIT;
+  t->scale.w = 0;
 }
 
 void S3L_lookAt(S3L_Vec4 pointFrom, S3L_Vec4 pointTo, S3L_Transform3D *t)
@@ -1370,7 +1376,8 @@ void S3L_lookAt(S3L_Vec4 pointFrom, S3L_Vec4 pointTo, S3L_Transform3D *t)
  
   dx = (v.x * S3L_FRACTIONS_PER_UNIT) / S3L_nonZero(l);
 
-  t->rotation.x = S3L_asin(dx);
+  t->rotation.x = -1 * S3L_asin(dx);
+
 }
 
 void S3L_setTransform3D(

todo.txt

@@ -24,6 +24,9 @@ features:
   interpolation -- it will randomly picky one of three values, with greater
   probabilities at greater coords
 
+- change the default backface culling to the other one (and edit the obj tool
+  accordingly)
+
 - option to disable baycentric coordinates computing    DONE
 
 - Z-buffer: