Add environment mapping.

Still need to combine this with the bump mapping.

3 files changed, 32 insertions, 2 deletions

diff --git a/src/main.cpp b/src/main.cpp
index 666c300..5fd429c 100755
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -101,8 +101,10 @@ static GLUmat4 projection_matrix;
 static GLuint prog;
 static GLint mvp_location;
 static GLint mv_location;
+static GLint m_location;
 static GLint s_location;
 static GLint sampler_location;
+static GLint eye_location;
 
 static GLuint cubemap;
 
@@ -141,7 +143,9 @@ Redisplay(const patch_set_info *info)
 		glUniform1f(s_location, specular_exponent[i]);
 		glUniformMatrix4fv(mvp_location, 1, false, (float *) &mvp);
 		glUniformMatrix4fv(mv_location, 1, false, (float *) &mv);
+		glUniformMatrix4fv(m_location, 1, false, (float *) &m);
 		glUniform1i(sampler_location, 0);
+		glUniform4fv(eye_location, 4, (float *) &eye);
 
 		glMultiDrawElements(info->mode, info->count, info->type,
 				    (const GLvoid**) info->indices,
@@ -266,6 +270,8 @@ load_and_compile_program_code(const char *shader)
 			glUseProgram(prog);
 			mvp_location = glGetUniformLocation(prog, "mvp");
 			mv_location = glGetUniformLocation(prog, "mv");
+			m_location = glGetUniformLocation(prog, "m");
+			eye_location = glGetUniformLocation(prog, "eye");
 			s_location = glGetUniformLocation(prog, "s");
 			sampler_location = glGetUniformLocation(prog, "sampler");
 		} else {
diff --git a/src/phong.frag b/src/phong.frag
index a21f8fa..b532b54 100755
--- a/src/phong.frag
+++ b/src/phong.frag
@@ -1,5 +1,8 @@
 uniform samplerCube sampler;
 
+varying vec3 normal_ws;
+varying vec3 eye_direction_ws;
+
 varying vec3 light_ss;
 varying vec3 eye_ss;
 varying vec2 uv_coord;
@@ -38,8 +41,11 @@ void main(void)
 	vec3 v = normalize(eye_ss);
 	vec3 h = normalize(l + v);
 	vec3 n = perturbed_normal();
+	vec3 i = reflect(eye_ss, n);
+	//vec3 diff = vec3(textureCube(sampler, i));
 	vec3 diff = base_color * dot(n, l);
 	float spec = pow(dot(n, h), s);
 
 	gl_FragColor = step(0.0, dot(n, l)) * vec4(diff + vec3(spec), 1.0);
+	//gl_FragColor = textureCube(sampler, reflect(eye_direction_ws, normal_ws));
 }
diff --git a/src/phong.vert b/src/phong.vert
index 3a57004..963c57b 100755
--- a/src/phong.vert
+++ b/src/phong.vert
@@ -1,10 +1,17 @@
-uniform mat4 mvp;
-uniform mat4 mv;
+uniform mat4 mvp; // eye -> screen
+uniform mat4 mv;  // world -> eye
+uniform mat4 m;   // object -> world
 
+// These three are in object space
 attribute vec4 normal;
 attribute vec4 tangent;
+attribute vec4 eye; // Eye position in object space
+
 attribute vec2 uv;
 
+varying vec3 normal_ws;
+varying vec3 eye_direction_ws;
+
 // Vector from the light to the vertex transformed to surface space.
 varying vec3 light_ss;
 
@@ -29,6 +36,17 @@ void main(void)
 	vec3 vertex_pos_es = vec3(mv * gl_Vertex);
 	vec3 light_direction_es = light_pos_es - vertex_pos_es;
 
+	/* Surface space vectors for lighting */
 	light_ss = normalize(light_direction_es * tbn);
 	eye_ss = -normalize(vertex_pos_es * tbn);
+
+	/* World space vectors for environment mapping
+	 * FIXME: eye should already be in world space, so I'm not sure why
+	 *        I have to do m * eye here.  But it looks wrong otherwise.
+	 */
+	vec3 vertex_pos_ws = vec3(m * gl_Vertex);
+	vec3 eye_pos_ws = vec3(m * eye);
+
+	normal_ws = vec3(m * normal);
+	eye_direction_ws = eye_pos_ws - vertex_pos_ws;
 }