From cdb4aca6643ebde7cfb7af332cb323ba2afacf15 Mon Sep 17 00:00:00 2001
From: rodri <rgl@antares-labs.eu>
Date: Sat, 21 Sep 2024 11:44:08 +0000
Subject: put all the shaders in a single file.

---
 shaders.inc | 421 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 421 insertions(+)
 create mode 100644 shaders.inc

(limited to 'shaders.inc')

diff --git a/shaders.inc b/shaders.inc
new file mode 100644
index 0000000..0e0d0fe
--- /dev/null
+++ b/shaders.inc
@@ -0,0 +1,421 @@
+
+Point3
+gouraudvshader(Shaderparams *sp)
+{
+	static double Ka = 0.1;	/* ambient factor */
+	static double Ks = 0.5;	/* specular factor */
+	double Kd;		/* diffuse factor */
+	double spec;
+	Point3 pos, lightdir, lookdir;
+	Material m;
+	Color ambient, diffuse, specular, lightc;
+
+	sp->v->n = model2world(sp->su->entity, sp->v->n);
+	sp->v->p = model2world(sp->su->entity, sp->v->p);
+	pos = sp->v->p;
+
+	if(sp->v->mtl != nil)
+		m = *sp->v->mtl;
+	else{
+		memset(&m, 0, sizeof m);
+		m.diffuse = sp->v->c;
+		m.specular = Pt3(1,1,1,1);
+		m.shininess = 1;
+	}
+
+	lightdir = normvec3(subpt3(light.p, pos));
+	lightc = getlightcolor(&light, lightdir);
+
+	ambient = mulpt3(lightc, Ka);
+	ambient = modulapt3(ambient, m.diffuse);
+
+	Kd = max(0, dotvec3(sp->v->n, lightdir));
+	diffuse = mulpt3(lightc, Kd);
+	diffuse = modulapt3(diffuse, m.diffuse);
+
+	lookdir = normvec3(subpt3(sp->su->camera->p, pos));
+	lightdir = qrotate(lightdir, sp->v->n, PI);
+	spec = pow(max(0, dotvec3(lookdir, lightdir)), m.shininess);
+	specular = mulpt3(lightc, spec*Ks);
+	specular = modulapt3(specular, m.specular);
+
+	sp->v->c = addpt3(ambient, addpt3(diffuse, specular));
+	sp->v->c.a = m.diffuse.a;
+	return world2clip(sp->su->camera, pos);
+}
+
+Color
+gouraudshader(Shaderparams *sp)
+{
+	Color tc;
+
+	if(sp->su->entity->mdl->tex != nil && sp->v->uv.w != 0)
+		tc = sampletexture(sp->su->entity->mdl->tex, sp->v->uv, tsampler);
+	else if(sp->v->mtl != nil && sp->v->mtl->diffusemap != nil && sp->v->uv.w != 0)
+		tc = sampletexture(sp->v->mtl->diffusemap, sp->v->uv, tsampler);
+	else
+		tc = Pt3(1,1,1,1);
+
+	sp->v->n.w = 1;
+	sp->toraster(sp, "normals", &sp->v->n);
+
+	return modulapt3(sp->v->c, tc);
+}
+
+Point3
+phongvshader(Shaderparams *sp)
+{
+	Point3 pos;
+	Color a, d, s;
+	double ss;
+
+	sp->v->n = model2world(sp->su->entity, sp->v->n);
+	sp->v->p = model2world(sp->su->entity, sp->v->p);
+	pos = sp->v->p;
+	sp->setattr(sp, "pos", VAPoint, &pos);
+	if(sp->v->mtl != nil && sp->v->mtl->normalmap != nil && sp->v->uv.w != 0){
+		sp->v->tangent = model2world(sp->su->entity, sp->v->tangent);
+		sp->setattr(sp, "tangent", VAPoint, &sp->v->tangent);
+	}
+	if(sp->v->mtl != nil){
+		a = sp->v->mtl->ambient;
+		d = sp->v->mtl->diffuse;
+		s = sp->v->mtl->specular;
+		ss = sp->v->mtl->shininess;
+		sp->setattr(sp, "ambient", VAPoint, &a);
+		sp->setattr(sp, "diffuse", VAPoint, &d);
+		sp->setattr(sp, "specular", VAPoint, &s);
+		sp->setattr(sp, "shininess", VANumber, &ss);
+	}
+	return world2clip(sp->su->camera, pos);
+}
+
+Color
+phongshader(Shaderparams *sp)
+{
+	static double Ka = 0.1;	/* ambient factor */
+	static double Ks = 0.5;	/* specular factor */
+	double Kd;		/* diffuse factor */
+	double spec;
+	Color ambient, diffuse, specular, lightc, c;
+	Point3 pos, n, lightdir, lookdir;
+	Material m;
+	RFrame3 TBN;
+	Vertexattr *va;
+
+	va = sp->getattr(sp, "pos");
+	pos = va->p;
+	
+	va = sp->getattr(sp, "ambient");
+	m.ambient = va != nil? va->p: Pt3(1,1,1,1);
+	va = sp->getattr(sp, "diffuse");
+	m.diffuse = va != nil? va->p: sp->v->c;
+	va = sp->getattr(sp, "specular");
+	m.specular = va != nil? va->p: Pt3(1,1,1,1);
+	va = sp->getattr(sp, "shininess");
+	m.shininess = va != nil? va->n: 1;
+
+	lightdir = normvec3(subpt3(light.p, pos));
+	lightc = getlightcolor(&light, lightdir);
+
+	/* normal mapping */
+	va = sp->getattr(sp, "tangent");
+	if(va == nil)
+		n = sp->v->n;
+	else{
+		/* TODO implement this on the VS instead and apply Gram-Schmidt here */
+		n = sampletexture(sp->v->mtl->normalmap, sp->v->uv, neartexsampler);
+		n = normvec3(subpt3(mulpt3(n, 2), Vec3(1,1,1)));
+
+		TBN.p = Pt3(0,0,0,1);
+		TBN.bx = va->p;				/* T */
+		TBN.bz = sp->v->n;			/* N */
+		TBN.by = crossvec3(TBN.bz, TBN.bx);	/* B */
+
+		n = normvec3(invrframexform3(n, TBN));
+		sp->v->n = n;
+	}
+
+	if(sp->su->entity->mdl->tex != nil && sp->v->uv.w != 0)
+		m.diffuse = sampletexture(sp->su->entity->mdl->tex, sp->v->uv, tsampler);
+	else if(sp->v->mtl != nil && sp->v->mtl->diffusemap != nil && sp->v->uv.w != 0)
+		m.diffuse = sampletexture(sp->v->mtl->diffusemap, sp->v->uv, tsampler);
+
+	ambient = mulpt3(lightc, Ka);
+	ambient = modulapt3(ambient, m.diffuse);
+
+	Kd = max(0, dotvec3(n, lightdir));
+	diffuse = mulpt3(lightc, Kd);
+	diffuse = modulapt3(diffuse, m.diffuse);
+
+	if(sp->v->mtl != nil && sp->v->mtl->specularmap != nil && sp->v->uv.w != 0)
+		m.specular = sampletexture(sp->v->mtl->specularmap, sp->v->uv, tsampler);
+
+	lookdir = normvec3(subpt3(sp->su->camera->p, pos));
+	lightdir = qrotate(lightdir, n, PI);
+	spec = pow(max(0, dotvec3(lookdir, lightdir)), m.shininess);
+	specular = mulpt3(lightc, spec*Ks);
+	specular = modulapt3(specular, m.specular);
+
+	sp->v->n.w = 1;
+	sp->toraster(sp, "normals", &sp->v->n);
+
+	c = addpt3(ambient, addpt3(diffuse, specular));
+	c.a = m.diffuse.a;
+	return c;
+}
+
+Color
+blinnshader(Shaderparams *sp)
+{
+	static double Ka = 0.1;	/* ambient factor */
+	static double Ks = 0.5;	/* specular factor */
+	double Kd;		/* diffuse factor */
+	double spec;
+	Color ambient, diffuse, specular, lightc, c;
+	Point3 pos, n, lightdir, lookdir;
+	Material m;
+	RFrame3 TBN;
+	Vertexattr *va;
+
+	va = sp->getattr(sp, "pos");
+	pos = va->p;
+	
+	va = sp->getattr(sp, "ambient");
+	m.ambient = va != nil? va->p: Pt3(1,1,1,1);
+	va = sp->getattr(sp, "diffuse");
+	m.diffuse = va != nil? va->p: sp->v->c;
+	va = sp->getattr(sp, "specular");
+	m.specular = va != nil? va->p: Pt3(1,1,1,1);
+	va = sp->getattr(sp, "shininess");
+	m.shininess = va != nil? va->n: 1;
+
+	lightdir = normvec3(subpt3(light.p, pos));
+	lightc = getlightcolor(&light, lightdir);
+
+	/* normal mapping */
+	va = sp->getattr(sp, "tangent");
+	if(va == nil)
+		n = sp->v->n;
+	else{
+		/* TODO implement this on the VS instead and apply Gram-Schmidt here */
+		n = sampletexture(sp->v->mtl->normalmap, sp->v->uv, neartexsampler);
+		n = normvec3(subpt3(mulpt3(n, 2), Vec3(1,1,1)));
+
+		TBN.p = Pt3(0,0,0,1);
+		TBN.bx = va->p;				/* T */
+		TBN.bz = sp->v->n;			/* N */
+		TBN.by = crossvec3(TBN.bz, TBN.bx);	/* B */
+
+		n = normvec3(invrframexform3(n, TBN));
+		sp->v->n = n;
+	}
+
+	if(sp->su->entity->mdl->tex != nil && sp->v->uv.w != 0)
+		m.diffuse = sampletexture(sp->su->entity->mdl->tex, sp->v->uv, tsampler);
+	else if(sp->v->mtl != nil && sp->v->mtl->diffusemap != nil && sp->v->uv.w != 0)
+		m.diffuse = sampletexture(sp->v->mtl->diffusemap, sp->v->uv, tsampler);
+
+	ambient = mulpt3(lightc, Ka);
+	ambient = modulapt3(ambient, m.diffuse);
+
+	Kd = max(0, dotvec3(n, lightdir));
+	diffuse = mulpt3(lightc, Kd);
+	diffuse = modulapt3(diffuse, m.diffuse);
+
+	if(sp->v->mtl != nil && sp->v->mtl->specularmap != nil && sp->v->uv.w != 0)
+		m.specular = sampletexture(sp->v->mtl->specularmap, sp->v->uv, tsampler);
+
+	lookdir = normvec3(subpt3(sp->su->camera->p, pos));
+	lightdir = normvec3(addpt3(lookdir, lightdir));	/* half vector */
+	spec = pow(max(0, dotvec3(n, lightdir)), m.shininess);
+	specular = mulpt3(lightc, spec*Ks);
+	specular = modulapt3(specular, m.specular);
+
+	sp->v->n.w = 1;
+	sp->toraster(sp, "normals", &sp->v->n);
+
+	c = addpt3(ambient, addpt3(diffuse, specular));
+	c.a = m.diffuse.a;
+	return c;
+}
+
+Point3
+toonvshader(Shaderparams *sp)
+{
+	Point3 pos, lightdir;
+	double intens;
+
+	sp->v->n = model2world(sp->su->entity, sp->v->n);
+	pos = model2world(sp->su->entity, sp->v->p);
+	lightdir = normvec3(subpt3(light.p, pos));
+	intens = max(0, dotvec3(sp->v->n, lightdir));
+	sp->setattr(sp, "intensity", VANumber, &intens);
+	if(sp->v->mtl != nil)
+		sp->v->c = sp->v->mtl->diffuse;
+	return world2clip(sp->su->camera, pos);
+}
+
+Color
+toonshader(Shaderparams *sp)
+{
+	Vertexattr *va;
+	double intens;
+
+	va = sp->getattr(sp, "intensity");
+	intens = va->n;
+	intens = intens > 0.85? 1:
+		 intens > 0.60? 0.80:
+		 intens > 0.45? 0.60:
+		 intens > 0.30? 0.45:
+		 intens > 0.15? 0.30: 0.15;
+
+	sp->v->n.w = 1;
+	sp->toraster(sp, "normals", &sp->v->n);
+
+	return Pt3(intens, 0.6*intens, 0, 1);
+}
+
+Point3
+identvshader(Shaderparams *sp)
+{
+	if(sp->v->mtl != nil)
+		sp->v->c = sp->v->mtl->diffuse;
+	return world2clip(sp->su->camera, model2world(sp->su->entity, sp->v->p));
+}
+
+Color
+identshader(Shaderparams *sp)
+{
+	Color tc;
+
+	if(sp->su->entity->mdl->tex != nil && sp->v->uv.w != 0)
+		tc = sampletexture(sp->su->entity->mdl->tex, sp->v->uv, tsampler);
+	else if(sp->v->mtl != nil && sp->v->mtl->diffusemap != nil && sp->v->uv.w != 0)
+		tc = sampletexture(sp->v->mtl->diffusemap, sp->v->uv, tsampler);
+	else
+		tc = Pt3(1,1,1,1);
+
+	sp->v->n.w = 1;
+	sp->toraster(sp, "normals", &sp->v->n);
+
+	return modulapt3(sp->v->c, tc);
+}
+
+Point3
+ivshader(Shaderparams *sp)
+{
+	sp->v->n = model2world(sp->su->entity, sp->v->n);
+	sp->v->p = model2world(sp->su->entity, sp->v->p);
+	return world2clip(sp->su->camera, sp->v->p);
+}
+
+Color
+triangleshader(Shaderparams *sp)
+{
+	Triangle2 t;
+	Rectangle bbox;
+	Point3 bc;
+
+	t.p0 = Pt2(240,200,1);
+	t.p1 = Pt2(400,40,1);
+	t.p2 = Pt2(240,40,1);
+
+	bbox = Rect(
+		min(min(t.p0.x, t.p1.x), t.p2.x), min(min(t.p0.y, t.p1.y), t.p2.y),
+		max(max(t.p0.x, t.p1.x), t.p2.x), max(max(t.p0.y, t.p1.y), t.p2.y)
+	);
+	if(!ptinrect(sp->p, bbox))
+		return Vec3(0,0,0);
+
+	bc = barycoords(t, Pt2(sp->p.x,sp->p.y,1));
+	if(bc.x < 0 || bc.y < 0 || bc.z < 0)
+		return Vec3(0,0,0);
+
+	return Pt3(bc.x, bc.y, bc.z, 1);
+}
+
+Color
+circleshader(Shaderparams *sp)
+{
+	Point2 uv;
+	double r, d;
+
+	uv = Pt2(sp->p.x,sp->p.y,1);
+	uv.x /= Dx(sp->su->fb->r);
+	uv.y /= Dy(sp->su->fb->r);
+//	r = 0.3;
+	r = 0.3*fabs(sin(sp->su->uni_time/1e9));
+	d = vec2len(subpt2(uv, Vec2(0.5,0.5)));
+
+	if(d > r + r*0.05 || d < r - r*0.05)
+		return Vec3(0,0,0);
+
+	return Pt3(uv.x, uv.y, 0, 1);
+}
+
+/* some shaping functions from The Book of Shaders, Chapter 5 */
+Color
+sfshader(Shaderparams *sp)
+{
+	Point2 uv;
+	double y, pct;
+
+	uv = Pt2(sp->p.x,sp->p.y,1);
+	uv.x /= Dx(sp->su->fb->r);
+	uv.y /= Dy(sp->su->fb->r);
+	uv.y = 1 - uv.y;		/* make [0 0] the bottom-left corner */
+
+//	y = step(0.5, uv.x);
+//	y = pow(uv.x, 5);
+//	y = sin(uv.x);
+	y = sin(uv.x*sp->su->uni_time/1e8)/2.0 + 0.5;
+//	y = smoothstep(0.1, 0.9, uv.x);
+	pct = smoothstep(y-0.02, y, uv.y) - smoothstep(y, y+0.02, uv.y);
+
+	return Pt3(flerp(y, 0, pct), flerp(y, 1, pct), flerp(y, 0, pct), 1);
+}
+
+Color
+boxshader(Shaderparams *sp)
+{
+	Point2 uv, p;
+	Point2 r;
+
+	uv = Pt2(sp->p.x,sp->p.y,1);
+	uv.x /= Dx(sp->su->fb->r);
+	uv.y /= Dy(sp->su->fb->r);
+	r = Vec2(0.2,0.4);
+
+	p = Pt2(fabs(uv.x - 0.5), fabs(uv.y - 0.5), 1);
+	p = subpt2(p, r);
+	p.x = max(p.x, 0);
+	p.y = max(p.y, 0);
+
+	if(vec2len(p) > 0)
+		return Vec3(0,0,0);
+
+	return Pt3(uv.x, uv.y, smoothstep(0,1,uv.x+uv.y), 1);
+}
+
+Shadertab shadertab[] = {
+	{ "triangle", ivshader, triangleshader },
+	{ "circle", ivshader, circleshader },
+	{ "box", ivshader, boxshader },
+	{ "sf", ivshader, sfshader },
+	{ "toon", toonvshader, toonshader },
+	{ "ident", identvshader, identshader },
+	{ "gouraud", gouraudvshader, gouraudshader },
+	{ "phong", phongvshader, phongshader },
+	{ "blinn", phongvshader, blinnshader },
+};
+Shadertab *
+getshader(char *name)
+{
+	int i;
+
+	for(i = 0; i < nelem(shadertab); i++)
+		if(strcmp(shadertab[i].name, name) == 0)
+			return &shadertab[i];
+	return nil;
+}
-- 
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