ref: 4923947f638c4bad0a4e02dc8ccde0db4d795571
parent: dc4da2505ec30449b9393182a3cb76937992dd3c
author: rodri <rgl@antares-labs.eu>
date: Wed Dec 13 06:32:00 EST 2023
Lesson 5 prelude: Gouraud shading (not fully working.) the normals from the file don't seem to be well formed, maybe the order is wrong or the indices.
--- a/main.c
+++ b/main.c
@@ -300,7 +300,7 @@
bresenham(dst, t[0], t[1], src);
bresenham(dst, t[1], t[2], src);
- bresenham(dst, t[2], t[0], green);
+ bresenham(dst, t[2], t[0], src);
}
void
@@ -339,7 +339,8 @@
Point p, tp;
Triangle2 st₂, tt₂;
Point3 bc;
- double z;
+ static Point3 light = {0,0,-1,0}; /* global light field */+ double z, intens[3];
uchar cbuf[4];
bbox = Rect(
@@ -357,6 +358,14 @@
if(bc.x < 0 || bc.y < 0 || bc.z < 0)
continue;
+ intens[0] = dotvec3(nt.p0, light);
+ intens[1] = dotvec3(nt.p1, light);
+ intens[2] = dotvec3(nt.p2, light);
+ intensity = intens[0]*bc.x + intens[1]*bc.y + intens[2]*bc.z;
+ /* back-face culling */
+ if(intensity <= 0)
+ continue;
+
z = st.p0.z*bc.x + st.p1.z*bc.y + st.p2.z*bc.z;
lock(&zbuflk);
if(z <= zbuf[p.x + p.y*Dx(dst->r)]){@@ -460,9 +469,10 @@
Triangle3 t, st, nt; /* world-, screen-space and normals triangles */
Triangle2 tt; /* texture triangle */
Point3 n; /* surface normal */
- static Point3 light = {0,0,-1,0}; /* global light field */- double intensity;
- Point3 np0, np1;
+// static Point3 light = {0,0,-1,0}; /* global light field */+// double intensity, intens[3];
+ Point3 np0, np1, bc;
+ Triangle2 st₂;
params = arg;
sp.frag = rgb(DBlack);
@@ -480,6 +490,10 @@
t.p1 = Pt3(verts[idxtab->indices[1]].x,verts[idxtab->indices[1]].y,verts[idxtab->indices[1]].z,verts[idxtab->indices[1]].w);
t.p2 = Pt3(verts[idxtab->indices[2]].x,verts[idxtab->indices[2]].y,verts[idxtab->indices[2]].z,verts[idxtab->indices[2]].w);
+ t.p0 = xform3(t.p0, rota);
+ t.p1 = xform3(t.p1, rota);
+ t.p2 = xform3(t.p2, rota);
+
st.p0 = xform3(t.p0, view);
st.p1 = xform3(t.p1, view);
st.p2 = xform3(t.p2, view);
@@ -487,15 +501,15 @@
st.p1 = divpt3(st.p1, st.p1.w);
st.p2 = divpt3(st.p2, st.p2.w);
- n = normvec3(crossvec3(subpt3(t.p2, t.p0), subpt3(t.p1, t.p0)));
- intensity = dotvec3(n, light);
- /* back-face culling */
- if(intensity <= 0)
- continue;
+// n = normvec3(crossvec3(subpt3(t.p2, t.p0), subpt3(t.p1, t.p0)));
+// intensity = dotvec3(n, light);
+// /* back-face culling */
+// if(intensity <= 0)
+// continue;
- np0 = centroid3(st);
- np1 = addpt3(np0, mulpt3(n, 10));
- bresenham(nfb, Pt(np0.x,np0.y), Pt(np1.x,np1.y), green);
+// np0 = centroid3(st);
+// np1 = addpt3(np0, mulpt3(n, 50));
+// bresenham(nfb, Pt(np0.x,np0.y), Pt(np1.x,np1.y), memwhite);
idxtab = &(*ep)->indextab[OBJVNormal];
if(modeltex != nil && idxtab->nindex == 3){@@ -502,6 +516,32 @@
nt.p0 = Vec3(nverts[idxtab->indices[0]].i, nverts[idxtab->indices[0]].j, nverts[idxtab->indices[0]].k);
nt.p1 = Vec3(nverts[idxtab->indices[1]].i, nverts[idxtab->indices[1]].j, nverts[idxtab->indices[1]].k);
nt.p2 = Vec3(nverts[idxtab->indices[2]].i, nverts[idxtab->indices[2]].j, nverts[idxtab->indices[2]].k);
+ nt.p0 = normvec3(nt.p0); nt.p0.z *= -1;
+ nt.p1 = normvec3(nt.p1); nt.p1.z *= -1;
+ nt.p2 = normvec3(nt.p2); nt.p2.z *= -1;
+// nt.p0 = mulpt3(normvec3(nt.p0), -1);
+// nt.p1 = mulpt3(normvec3(nt.p1), -1);
+// nt.p2 = mulpt3(normvec3(nt.p2), -1);
+// intens[0] = dotvec3(nt.p0, light);
+// intens[1] = dotvec3(nt.p1, light);
+// intens[2] = dotvec3(nt.p2, light);
+
+ st₂.p0 = Pt2(st.p0.x, st.p0.y, 1);
+ st₂.p1 = Pt2(st.p1.x, st.p1.y, 1);
+ st₂.p2 = Pt2(st.p2.x, st.p2.y, 1);
+ bc = barycoords(st₂, centroid(st₂));
+ np0 = centroid3(st);
+ np1 = Vec3(
+ nt.p0.x*bc.x + nt.p1.x*bc.y + nt.p2.x*bc.z,
+ nt.p0.y*bc.x + nt.p1.y*bc.y + nt.p2.y*bc.z,
+ nt.p0.z*bc.x + nt.p1.z*bc.y + nt.p2.z*bc.z);
+// intensity = intens[0]*bc.x + intens[1]*bc.y + intens[2]*bc.z;
+// /* back-face culling */
+// if(intensity <= 0)
+// continue;
+ np1 = addpt3(np0, mulpt3(np1, 50));
+ triangle(nfb, Pt(st.p0.x,st.p0.y), Pt(st.p1.x,st.p1.y), Pt(st.p2.x,st.p2.y), red);
+ bresenham(nfb, Pt(np0.x,np0.y), Pt(np1.x,np1.y), green);
}else
memset(&nt, 0, sizeof nt);
@@ -513,7 +553,7 @@
}else
memset(&tt, 0, sizeof tt);
- filltriangle2(params->dst, st, nt, tt, intensity, sp.frag);
+ filltriangle2(params->dst, st, nt, tt, 0, sp.frag);
}
freememimage(sp.frag);
@@ -960,7 +1000,6 @@
};
identity3(rota);
mulm3(rota, yrot);
- mulm3(proj, rota);
mulm3(view, proj);
rendering = 1;
proccreate(renderer, nil, mainstacksize);