Stop rendering all those times and just use ward.

2 files changed, 59 insertions, 146 deletions

diff --git a/glass.c b/glass.c
index 4ae1182..e536df2 100644
--- a/glass.c
+++ b/glass.c
@@ -58,20 +58,10 @@ struct revolved_object {
 	int num_verts, num_steps;
 };
 
-enum rendering_mode {
-	RENDER_PHONG,
-	RENDER_FRESNEL,
-	RENDER_COOK_TORRANCE,
-	RENDER_WARD_ANISO,
-	MAX_RENDER_MODE,
-};
-
 enum uniform_list {
 	UNIFORM_LIGHT_EYE,
 	UNIFORM_NORMAL_SAMPLER,
 	UNIFORM_HEIGHTMAP_SAMPLER,
-	UNIFORM_RENDER_MODE,
-	UNIFORM_RENDER_ITER,
 	UNIFORM_NI,
 	UNIFORM_F0,
 };
@@ -83,8 +73,6 @@ struct uniform_desc {
 	[UNIFORM_LIGHT_EYE] = { "light_eye" },
 	[UNIFORM_NORMAL_SAMPLER] = { "normal_sampler" },
 	[UNIFORM_HEIGHTMAP_SAMPLER] = { "heightmap_sampler" },
-	[UNIFORM_RENDER_MODE] = { "render_mode" },
-	[UNIFORM_RENDER_ITER] = { "render_iter" },
 	[UNIFORM_NI] = { "ni" },
 	[UNIFORM_F0] = { "F0" },
 };
@@ -258,21 +246,11 @@ draw(void)
 
 	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER_ARB, ring.vbo);
 
-	for (i = 0; i < MAX_RENDER_MODE; i++) {
-		for (j = 0; j < 3; j++) {
-			glUniform1f(uniforms[UNIFORM_RENDER_MODE].location, i);
-			glUniform1f(uniforms[UNIFORM_RENDER_ITER].location, j);
-			glViewport(win_width * j / 3,
-				   win_height * i / MAX_RENDER_MODE,
-				   win_width / 3,
-				   win_height / MAX_RENDER_MODE);
+	glViewport(0, 0, win_width, win_height);
 
-			for (instance = 0; instance < 3; instance++) {
-				install_transform(instance);
-
-				do_ring_drawelements();
-			}
-		}
+	for (instance = 0; instance < 3; instance++) {
+		install_transform(instance);
+		do_ring_drawelements();
 	}
 
 	glDisable(GL_VERTEX_ARRAY);
@@ -450,8 +428,7 @@ reshape(int width, int height)
 
 	glMatrixMode(GL_PROJECTION);
 	glLoadIdentity();
-	gluPerspective(80, (win_width / 3) / ((float)win_height / MAX_RENDER_MODE),
-		       0.2, 40);
+	gluPerspective(80, win_width / (float)win_height, 0.2, 40);
 
 	glutPostRedisplay();
 }
diff --git a/glass.frag b/glass.frag
index 8db3251..6575a0b 100644
--- a/glass.frag
+++ b/glass.frag
@@ -4,7 +4,6 @@ varying vec3 tangent_surf;
 varying vec2 texcoord;
 uniform sampler2D normal_sampler;
 uniform sampler2D heightmap_sampler;
-uniform float render_mode, render_iter;
 uniform float F0, ni;
 
 float schlick_fresnel(float n_dot_l)
@@ -42,133 +41,70 @@ void main()
 	float n_dot_v = dot(n, v);
 	float n_dot_h = dot(n, h);
 	float v_dot_h = dot(v, h);
+	float s = .7;
+	float d = 1 - s;
+	float Ii = 0.9; /*intensity of incoming light */
+	float Iia = .1 * Ii; /*intensity of ambient light */
+
+	float cos2_alpha = n_dot_h * n_dot_h;
+	float tan2_alpha = (1 - cos2_alpha) / cos2_alpha;
+	float Rs;
+	float D;
+
+	/* Aniso BRDF from Ward's "Measuring and Modeling
+	 * Anisotropic Reflection".
+	 */
 
-	if (render_mode == 0) {
-		float spec_exponent;
-		if (render_iter == 0)
-			spec_exponent = 5;
-		else if (render_iter == 1)
-			spec_exponent = 16;
-		else
-			spec_exponent = 40;
-
-		vec3 diffuse = material_color.xyz * max(n_dot_l, 0);
-		float specular = pow(h.z, spec_exponent);
-		gl_FragColor = n_dot_l * vec4(diffuse + vec3(specular),
-					      material_color.w);
-	} else if (render_mode == 1) {
-		float spec_exponent;
-		if (render_iter == 0)
-			spec_exponent = 5;
-		else if (render_iter == 1)
-			spec_exponent = 16;
-		else
-			spec_exponent = 40;
-
-		vec3 diffuse = material_color.xyz * max(n_dot_l, 0);
-		float specular = pow(h.z, 16.0);
-		float F = schlick_fresnel(n_dot_l);
-		gl_FragColor = n_dot_l * vec4(mix(diffuse, vec3(specular), F),
-					      material_color.w);
-	} else {
-		float s = .7;
-		float d = 1 - s;
-		float Ii = 0.9; /*intensity of incoming light */
-		float Iia = .1 * Ii; /*intensity of ambient light */
-
-		float m = .15 * render_iter;
-		float cos2_alpha = n_dot_h * n_dot_h;
-		float tan2_alpha = (1 - cos2_alpha) / cos2_alpha;
-		float Rs;
-		float D;
-
-		if (render_mode == 2) {
-			/* Beckmann distribution function from Torrance */
-			D = exp(-tan2_alpha / (m * m)) /
-				(4 * m * m * cos2_alpha * cos2_alpha);
-
-			float G1 = 2 * n_dot_h * n_dot_v / v_dot_h;
-			float G2 = 2 * n_dot_h * n_dot_l / v_dot_h;
-			float G = clamp(min(G1, G2), 0, 1);
-
-#if 0
-			float F = fresnel(v_dot_h);
-#else
-			float F = schlick_fresnel(n_dot_l);
-#endif
-			Rs = 2 * F * D * G / (n_dot_l * n_dot_v);
-		} else {
-			/* Aniso BRDF from Ward's "Measuring and Modeling
-			 * Anisotropic Reflection".
-			 */
-
-			/* alpha_x and alpha_y. Values below from Ward */
-			float n, m;
-
-			if (render_iter == 0) {
-				/* rolled brass*/
-				n = .05;
-				m = .16;
-			} else if (render_iter == 1) {
-				/* ivory computer plastic */
-				n = m = .13;
-			} else {
-				/* brushed metal */
-				n = .037;
-				m = .063;
-			}
+	/* brushed metal */
+	float ward_n = .037;
+	float ward_m = .063;
 
-			/* Make phi be the angle between the projections of
-			 * the tangent and half-angle vectors onto the
-			 * surface plane (z=0).  Doing it right would involve
-			 * projecting onto the plane defined by n.
-			 */
-			float cos_phi = dot(normalize(t.xy), normalize(h.xy));
+	/* Make phi be the angle between the projections of
+	 * the tangent and half-angle vectors onto the
+	 * surface plane (z=0).  Doing it right would involve
+	 * projecting onto the plane defined by n.
+	 */
+	float cos_phi = dot(normalize(t.xy), normalize(h.xy));
 
-			float cos2_phi_over_m2 = ((cos_phi * cos_phi) /
-						  (m * m));
-			float sin2_phi_over_n2 = ((1 - cos_phi * cos_phi) /
-						  (n * n));
+	float cos2_phi_over_m2 = ((cos_phi * cos_phi) / (ward_m * ward_m));
+	float sin2_phi_over_n2 = ((1 - cos_phi * cos_phi) / (ward_n * ward_n));
 #if 1
-			D = exp(-tan2_alpha * (cos2_phi_over_m2 +
-					       sin2_phi_over_n2));
+	D = exp(-tan2_alpha * (cos2_phi_over_m2 + sin2_phi_over_n2));
 #else
-			/* Ward's "computationally convenient" equation.
-			 * Doesn't work.
-			 */
-			D = exp(-2 * (cos2_phi_over_m2 +
-				      sin2_phi_over_n2) /
-				(1 + n_dot_h));
+	/* Ward's "computationally convenient" equation.
+	 * Doesn't work.
+	 */
+	D = exp(-2 * (cos2_phi_over_m2 +
+		      sin2_phi_over_n2) /
+		(1 + n_dot_h));
 #endif
-			Rs = 2 * schlick_fresnel(n_dot_l) * D /
-				sqrt(n_dot_l * n_dot_v) / (m * n);
-		}
+	Rs = 2 * schlick_fresnel(n_dot_l) * D /
+	  sqrt(n_dot_l * n_dot_v) / (ward_m * ward_n);
 
-		Rs *= step(0, n_dot_l);
-		Rs *= step(0, n_dot_v);
+	Rs *= step(0, n_dot_l);
+	Rs *= step(0, n_dot_v);
 
-		float Rd = (1 - F0) * 2;
-		/* Ambient occlusion factor -- sample the height map we
-		 * used to generate the normal map, and reduce intensity in
-		 * the valleys.
-		 */
-		float heightmap = texture2D(heightmap_sampler, texcoord).x;
-		float Ra = Rd * (.8 + .2 * heightmap);
-
-		gl_FragColor = n_dot_l * step(0, n_dot_l) *
-			vec4(material_color.xyz *
-			     (Rd * d + Rs * s),
-			     material_color.w) +
-		  Iia * Ra * material_color.xyzw;
-
-		/* Debugging scalars -- Map [0,1] to [0.5,1] to catch negative
-		 * values.  Multiply by the step function to catch when
-		 * the scalar won't come into play because Rs == 0.
-		 */
+	float Rd = (1 - F0) * 2;
+	/* Ambient occlusion factor -- sample the height map we
+	 * used to generate the normal map, and reduce intensity in
+	 * the valleys.
+	 */
+	float heightmap = texture2D(heightmap_sampler, texcoord).x;
+	float Ra = Rd * (.8 + .2 * heightmap);
+
+	gl_FragColor = n_dot_l * step(0, n_dot_l) *
+	  vec4(material_color.xyz *
+	       (Rd * d + Rs * s),
+	       material_color.w) +
+	  Iia * Ra * material_color.xyzw;
+
+	/* Debugging scalars -- Map [0,1] to [0.5,1] to catch negative
+	 * values.  Multiply by the step function to catch when
+	 * the scalar won't come into play because Rs == 0.
+	 */
 #if 0
-		gl_FragColor = vec4(vec3(F0 / 2 + .5), 1);
+	gl_FragColor = vec4(vec3(F0 / 2 + .5), 1);
 #endif
-	}
 /* Normal visualization */
 /*
 vec3 temp = vec3((normal.x + 1) / 2,