Simplify shaders by moving fill-in light to a separate program

git-svn-id: svn://cook.msm.cam.ac.uk:745/thrust3d/thrust3d@218 84d2e878-0bd5-11dd-ad15-13eda11d74c5

6 files changed, 178 insertions, 52 deletions

diff --git a/data/Makefile.am b/data/Makefile.am
index f4ec188..b818d11 100644
--- a/data/Makefile.am
+++ b/data/Makefile.am
@@ -4,7 +4,8 @@ models_DATA = models/floor models/lander models/randombox models/walle models/wa
 		models/pipe-horiz
 
 shadersdir = $(datadir)/thrust3d/shaders
-shaders_DATA = shaders/lighting.vert shaders/lighting.frag shaders/swirlytron.vert shaders/swirlytron.frag
+shaders_DATA = shaders/lighting.vert shaders/lighting.frag shaders/swirlytron.vert shaders/swirlytron.frag \
+		shaders/fill-light.vert shaders/fill-light.frag
 
 texturesdir = $(datadir)/thrust3d/textures
 textures_DATA = textures/floor1.png textures/tiledwall.png textures/radioactive.png textures/fuel.png \
diff --git a/data/shaders/fill-light.frag b/data/shaders/fill-light.frag
new file mode 100644
index 0000000..b9aba4c
--- /dev/null
+++ b/data/shaders/fill-light.frag
@@ -0,0 +1,84 @@
+/*
+ * lighting.frag
+ *
+ * Lighting calculations
+ *
+ * (c) 2007-2008 Thomas White <taw27@cam.ac.uk>
+ *
+ *  thrust3d - a silly game
+ *
+ */
+
+varying vec3 pos;
+varying vec3 normal;
+
+varying vec3 light2vc;
+
+uniform sampler2D texture;
+uniform sampler2D normalmap;
+
+uniform bool has_normals;
+uniform bool texture_enabled;
+uniform bool texture_emits;
+uniform float alpha;
+
+varying vec3 col_ambi_diff;
+varying vec3 col_emit;
+
+void main() {
+	
+	vec3 ambi;
+	vec3 emit;
+	vec3 diff = vec3(0.0, 0.0, 0.0);
+	vec3 spec = vec3(0.0, 0.0, 0.0);
+	vec3 norm = normal;
+	float diff_fac, spec_fac;
+	vec3 L, E, R;
+	
+	if ( has_normals ) {
+		norm += (texture2D(normalmap, gl_TexCoord[0].st).rgb - vec3(0.5, 0.5, 0.5)) / 2.0;
+	}
+	
+	norm = normalize(norm);
+	
+	/* Ambient */
+	ambi = col_ambi_diff * gl_LightModel.ambient.rgb;
+	
+	/* Emission */
+	emit = col_emit;
+		
+	/* Light 2: Fill-in for lander craft */
+	L = normalize(gl_LightSource[2].position.xyz - pos); 
+	E = normalize(-pos);
+	R = normalize(-reflect(L, norm)); 
+	diff_fac = max(0.0, dot(normalize(light2vc).xyz, norm));
+	spec_fac = max(0.0, dot(R, E));
+	spec_fac = pow(spec_fac, 80.0);
+
+	diff += col_ambi_diff * gl_LightSource[2].diffuse.rgb * diff_fac;
+	spec += gl_LightSource[2].specular.rgb * spec_fac;
+
+	if ( texture_enabled ) {
+	
+		vec3 tex = texture2D(texture, gl_TexCoord[0].st).rgb;
+		
+		if ( texture_emits ) {
+			gl_FragColor = vec4(tex.r, tex.g, tex.b, alpha);
+		} else {
+			gl_FragColor = vec4(min(tex.r * (ambi.r + diff.r) + spec.r, 1.0),
+					    min(tex.g * (ambi.g + diff.g) + spec.g, 1.0),
+					    min(tex.b * (ambi.b + diff.b) + spec.b, 1.0),
+					    alpha);
+		}
+	
+	} else {
+
+		gl_FragColor = vec4(min(emit.r + ambi.r + diff.r + spec.r, 1.0),
+				    min(emit.g + ambi.g + diff.g + spec.g, 1.0),
+				    min(emit.b + ambi.b + diff.b + spec.b, 1.0),
+				    alpha);
+
+	}
+
+}
+
diff --git a/data/shaders/fill-light.vert b/data/shaders/fill-light.vert
new file mode 100644
index 0000000..38dcfc9
--- /dev/null
+++ b/data/shaders/fill-light.vert
@@ -0,0 +1,40 @@
+/*
+ * fill-light.vert
+ *
+ * Lighting calculations for the lander craft
+ *
+ * (c) 2007-2008 Thomas White <taw27@cam.ac.uk>
+ *
+ *  thrust3d - a silly game
+ *
+ */
+
+varying vec3 pos;
+varying vec3 normal;
+
+varying vec3 light2vc;
+
+varying vec3 col_ambi_diff;
+varying vec3 col_emit;
+
+void main() {
+	
+	vec4 vert;
+	
+	vert = gl_ModelViewMatrix * gl_Vertex;
+	pos = vert.xyz;
+	normal = gl_NormalMatrix * gl_Normal;
+	
+	/* Light 2: Fill-in light for lander */
+	light2vc = normalize(vec3(gl_LightSource[2].position));
+	
+	/* Material properties */
+	col_ambi_diff = gl_Color.rgb;
+	col_emit = gl_FrontMaterial.emission.rgb;
+	
+	/* Coordinates */
+	gl_TexCoord[0] = gl_TextureMatrix[0] * gl_MultiTexCoord0;
+	gl_Position = ftransform();
+	
+}
+
diff --git a/data/shaders/lighting.frag b/data/shaders/lighting.frag
index 7ec0d3e..39f39fc 100644
--- a/data/shaders/lighting.frag
+++ b/data/shaders/lighting.frag
@@ -37,6 +37,9 @@ void main() {
 	vec3 diff = vec3(0.0, 0.0, 0.0);
 	vec3 spec = vec3(0.0, 0.0, 0.0);
 	vec3 norm = normal;
+	float falloff, spot;
+	float diff_fac, spec_fac;
+	vec3 L, E, R;
 	
 	if ( has_normals ) {
 		norm += (texture2D(normalmap, gl_TexCoord[0].st).rgb - vec3(0.5, 0.5, 0.5)) / 2.0;
@@ -49,53 +52,29 @@ void main() {
 	
 	/* Emission */
 	emit = col_emit;
-		
-	if ( fill_light_enabled ) {
-		
-		float diff_fac, spec_fac;
-		vec3 L, E, R;
-		
-		/* Light 2: Fill-in for lander craft */
-		L = normalize(gl_LightSource[2].position.xyz - pos); 
-		E = normalize(-pos);
-		R = normalize(-reflect(L, norm)); 
-		diff_fac = max(0.0, dot(normalize(light2vc).xyz, norm));
-		spec_fac = max(0.0, dot(R, E));
-		spec_fac = pow(spec_fac, 80.0);
-		
-		diff += col_ambi_diff * gl_LightSource[2].diffuse.rgb * diff_fac;
-		spec += gl_LightSource[2].specular.rgb * spec_fac;
-
-	} else {
 	
-		float falloff, spot;
-		float diff_fac, spec_fac;
-		vec3 L, E, R;
-		
-		/* Light 0: Lander craft's spotlight */
-		falloff = 1.0 / (  gl_LightSource[0].constantAttenuation
-			            + gl_LightSource[0].linearAttenuation * length(light0vc)
-			            + gl_LightSource[0].quadraticAttenuation * pow(length(light0vc), 2.0) );
-		
-		spot = max(dot(normalize(-light0vc), gl_LightSource[0].spotDirection), 0.0);
-		spot = pow(spot, gl_LightSource[0].spotExponent);
-		
-		diff_fac = max(0.0, dot(normalize(light0vc).xyz, norm));
-		
-		L = normalize(gl_LightSource[0].position.xyz - pos); 
-		E = normalize(-pos);
-		R = normalize(-reflect(L, norm)); 
-		spec_fac = max(0.0, dot(R, E));
-		spec_fac = pow(spec_fac, 80.0);
-		
-		diff += col_ambi_diff * gl_LightSource[0].diffuse.rgb * spot * falloff * diff_fac;
-		
-		spec += vec3(1.0, 1.0, 1.0) * gl_LightSource[0].specular.rgb * spot * falloff * spec_fac;
-		
-		/* Light 1: Diffuse background glow */
-		diff += col_ambi_diff * gl_LightSource[1].diffuse.rgb * max(0.0, dot(vec3(light1vc), norm));
-
-	}
+	/* Light 0: Lander craft's spotlight */
+	falloff = 1.0 / (  gl_LightSource[0].constantAttenuation
+		            + gl_LightSource[0].linearAttenuation * length(light0vc)
+		            + gl_LightSource[0].quadraticAttenuation * pow(length(light0vc), 2.0) );
+	
+	spot = max(dot(normalize(-light0vc), gl_LightSource[0].spotDirection), 0.0);
+	spot = pow(spot, gl_LightSource[0].spotExponent);
+	
+	diff_fac = max(0.0, dot(normalize(light0vc).xyz, norm));
+	
+	L = normalize(gl_LightSource[0].position.xyz - pos); 
+	E = normalize(-pos);
+	R = normalize(-reflect(L, norm)); 
+	spec_fac = max(0.0, dot(R, E));
+	spec_fac = pow(spec_fac, 80.0);
+	
+	diff += col_ambi_diff * gl_LightSource[0].diffuse.rgb * spot * falloff * diff_fac;
+	
+	spec += vec3(1.0, 1.0, 1.0) * gl_LightSource[0].specular.rgb * spot * falloff * spec_fac;
+	
+	/* Light 1: Diffuse background glow */
+	diff += col_ambi_diff * gl_LightSource[1].diffuse.rgb * max(0.0, dot(vec3(light1vc), norm));
 	
 	if ( texture_enabled ) {
 	
diff --git a/src/render.c b/src/render.c
index ce25c5e..26d1dcc 100644
--- a/src/render.c
+++ b/src/render.c
@@ -40,6 +40,15 @@ static void render_load_shaders(RenderContext *r) {
 	shaderutils_link_program(r->lighting_program);
 	shaderutils_validate_program(r->lighting_program);
 	
+	/* Fill-in light */
+	r->fill_vert = shaderutils_load_shader(DATADIR"/shaders/fill-light.vert", GL_VERTEX_SHADER);
+	r->fill_frag = shaderutils_load_shader(DATADIR"/shaders/fill-light.frag", GL_FRAGMENT_SHADER);
+	r->fill_program = glCreateProgram();
+	glAttachShader(r->fill_program, r->fill_vert);
+	glAttachShader(r->fill_program, r->fill_frag);
+	shaderutils_link_program(r->fill_program);
+	shaderutils_validate_program(r->fill_program);
+	
 	/* Swirlyness */
 	r->swirly_vert = shaderutils_load_shader(DATADIR"/shaders/swirlytron.vert", GL_VERTEX_SHADER);
 	r->swirly_frag = shaderutils_load_shader(DATADIR"/shaders/swirlytron.frag", GL_FRAGMENT_SHADER);
@@ -58,6 +67,18 @@ static void render_delete_shaders(RenderContext *r) {
 	glDeleteShader(r->lighting_vert);
 	glDeleteShader(r->lighting_frag);
 	glDeleteProgram(r->lighting_program);
+
+	glDetachShader(r->fill_program, r->fill_frag);
+	glDetachShader(r->fill_program, r->fill_vert);
+	glDeleteShader(r->fill_vert);
+	glDeleteShader(r->fill_frag);
+	glDeleteProgram(r->fill_program);
+
+	glDetachShader(r->swirly_program, r->swirly_frag);
+	glDetachShader(r->swirly_program, r->swirly_vert);
+	glDeleteShader(r->swirly_vert);
+	glDeleteShader(r->swirly_frag);
+	glDeleteProgram(r->swirly_program);
 	
 }
 
@@ -604,7 +625,6 @@ void render_draw(Game *game, Uint32 t) {
 		shaderutils_setuni(game->render->lighting_program, "texture_only", 0);
 		shaderutils_setuni(game->render->lighting_program, "texture_enabled", 1);
 		shaderutils_setuni(game->render->lighting_program, "has_normals", 0);
-		shaderutils_setuni(game->render->lighting_program, "fill_light_enabled", 0);
 	}
 	render_setup_lighting(game);
 	amb[0] = 0.02;  amb[1] = 0.02;  amb[2] = 0.02;
@@ -619,17 +639,16 @@ void render_draw(Game *game, Uint32 t) {
 	glEnableClientState(GL_VERTEX_ARRAY);
 	glEnableClientState(GL_NORMAL_ARRAY);
 	glEnableClientState(GL_TEXTURE_COORD_ARRAY);
-	if ( r->shaders ) shaderutils_setuni(game->render->lighting_program, "fill_light_enabled", 1);
+	if ( r->shaders ) glUseProgram(game->render->fill_program);
 	render_model_instance_draw(game->lander, t, r, NULL, 1.0);
-	if ( r->shaders ) shaderutils_setuni(game->render->lighting_program, "fill_light_enabled", 0);
 	glPopClientAttrib();
-	if ( r->shaders ) shaderutils_setuni(game->render->lighting_program, "texture_enabled", 0);
+	if ( r->shaders ) glUseProgram(0);
 	render_draw_line(game->lander->x, game->lander->y, game->lander->z,
 			 game->lander->x, game->lander->y, game->lander->z-200.0);
 	glDisable(GL_LIGHT2);
 	
 	/* Back faces (done last to make blending work properly) */
-	if ( r->shaders ) glUseProgram(0); /* Speed things up a bit by not using per-fragment lighting */
+	/* Shaders still disabled (speeds this up a lot) */
 	glFrontFace(GL_CW);
 	glPolygonOffset(1.0, 1.0);
 	glEnable(GL_POLYGON_OFFSET_FILL);
diff --git a/src/types.h b/src/types.h
index f601d95..550d931 100644
--- a/src/types.h
+++ b/src/types.h
@@ -139,6 +139,9 @@ typedef struct {
 	GLuint	lighting_vert;
 	GLuint	lighting_frag;
 	GLuint	lighting_program;
+	GLuint	fill_vert;
+	GLuint	fill_frag;
+	GLuint	fill_program;
 
 	/* Textures */
 	Texture		textures[MAX_TEXTURES];