Shader optimisations (use blank texture when none specified)

git-svn-id: svn://cook.msm.cam.ac.uk:745/thrust3d/thrust3d@220 84d2e878-0bd5-11dd-ad15-13eda11d74c5

6 files changed, 53 insertions, 75 deletions

diff --git a/data/Makefile.am b/data/Makefile.am
index b818d11..beca98a 100644
--- a/data/Makefile.am
+++ b/data/Makefile.am
@@ -9,7 +9,7 @@ shaders_DATA = shaders/lighting.vert shaders/lighting.frag shaders/swirlytron.ve
 
 texturesdir = $(datadir)/thrust3d/textures
 textures_DATA = textures/floor1.png textures/tiledwall.png textures/radioactive.png textures/fuel.png \
-		textures/font.png textures/concrete.png textures/tiledwall-normals.png
+		textures/font.png textures/concrete.png textures/tiledwall-normals.png textures/placeholder.png
 
 roomsdir = $(datadir)/thrust3d/rooms
 rooms_DATA = rooms/00-00-00 rooms/00-00-01 rooms/00-00-02 rooms/00-00-03 rooms/00-00-04 rooms/00-01-04 rooms/00-02-04
diff --git a/data/shaders/fill-light.frag b/data/shaders/fill-light.frag
index b9aba4c..6a7044e 100644
--- a/data/shaders/fill-light.frag
+++ b/data/shaders/fill-light.frag
@@ -1,7 +1,7 @@
 /*
- * lighting.frag
+ * fill-light.frag
  *
- * Lighting calculations
+ * Simplified lighting calculations for the lander craft
  *
  * (c) 2007-2008 Thomas White <taw27@cam.ac.uk>
  *
@@ -18,8 +18,6 @@ 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;
@@ -27,26 +25,26 @@ 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;
+	vec3 ambi, emit, diff, spec;
+	vec3 norm;
 	float diff_fac, spec_fac;
 	vec3 L, E, R;
+	vec3 tex;
+	
+	tex = texture2D(texture, gl_TexCoord[0].st).rgb;
 	
 	if ( has_normals ) {
 		norm += (texture2D(normalmap, gl_TexCoord[0].st).rgb - vec3(0.5, 0.5, 0.5)) / 2.0;
 	}
 	
-	norm = normalize(norm);
+	norm = normalize(normal);
 	
 	/* 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);
@@ -54,31 +52,14 @@ void main() {
 	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);
-		}
+	diff = col_ambi_diff * gl_LightSource[2].diffuse.rgb * diff_fac;
+	spec = gl_LightSource[2].specular.rgb * spec_fac;
 	
-	} 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);
-
-	}
+	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);
 
 }
 
diff --git a/data/shaders/fill-light.vert b/data/shaders/fill-light.vert
index 38dcfc9..bdcb844 100644
--- a/data/shaders/fill-light.vert
+++ b/data/shaders/fill-light.vert
@@ -1,7 +1,7 @@
 /*
  * fill-light.vert
  *
- * Lighting calculations for the lander craft
+ * Simplified lighting calculations for the lander craft
  *
  * (c) 2007-2008 Thomas White <taw27@cam.ac.uk>
  *
diff --git a/data/shaders/lighting.frag b/data/shaders/lighting.frag
index 39f39fc..632f870 100644
--- a/data/shaders/lighting.frag
+++ b/data/shaders/lighting.frag
@@ -13,17 +13,13 @@ varying vec3 pos;
 varying vec3 normal;
 
 varying vec3 light0vc;
-varying vec3 light0half;
 varying vec3 light1vc;
 varying vec3 light2vc;
-varying vec3 light2hvc;
 
 uniform sampler2D texture;
 uniform sampler2D normalmap;
 
 uniform bool has_normals;
-uniform bool fill_light_enabled;
-uniform bool texture_enabled;
 uniform bool texture_emits;
 uniform float alpha;
 
@@ -32,21 +28,28 @@ 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;
+	vec3 ambi, emit, diff, spec;
+	vec3 norm;
 	float falloff, spot;
 	float diff_fac, spec_fac;
 	vec3 L, E, R;
+	vec3 tex;
 	
+	tex = texture2D(texture, gl_TexCoord[0].st).rgb;
+	if ( texture_emits ) {
+		gl_FragColor = vec4(tex.r, tex.g, tex.b, alpha);
+		return;	/* Bail out early in this case */
+	}
+	
+	diff = vec3(0.0, 0.0, 0.0);
+	spec = vec3(0.0, 0.0, 0.0);
+	
+	norm = normalize(normal);
 	if ( has_normals ) {
+		/* Same texture coordinates as for the diffuse map */
 		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;
 	
@@ -70,33 +73,15 @@ void main() {
 	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 ) {
-	
-		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),
+	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);
 
-	}
-
 }
 
diff --git a/data/textures/placeholder.png b/data/textures/placeholder.png
new file mode 100644
index 0000000..5eda9f1
--- /dev/null
+++ b/data/textures/placeholder.png
diff --git a/src/render.c b/src/render.c
index 26d1dcc..84de330 100644
--- a/src/render.c
+++ b/src/render.c
@@ -185,6 +185,7 @@ RenderContext *render_setup(int width, int height, int disable_vbos, int disable
 	/* Load misc texture bits */
 	texture_load(r, "radioactive");
 	texture_load(r, "fuel");
+	texture_load(r, "placeholder");
 	
 	render_text_setup(r);
 	
@@ -209,6 +210,20 @@ static GLenum render_gltype(PrimitiveType type) {
 
 }
 
+static void render_placeholder_texture(RenderContext *r) {
+
+	Texture *texture;
+	
+	texture = texture_lookup(r, "placeholder");
+	if ( texture != NULL ) {
+		glBindTexture(GL_TEXTURE_2D, texture->texname);
+		glEnable(GL_TEXTURE_2D);
+	} else {
+		fprintf(stderr, "Couldn't find placeholder texture!\n");
+	}
+
+}
+
 static int render_model_instance_draw(ModelInstance *instance, Uint32 t, RenderContext *r, int *nvert, GLfloat alpha) {
 
 	int j;
@@ -271,9 +286,8 @@ static int render_model_instance_draw(ModelInstance *instance, Uint32 t, RenderC
 				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 				shaderutils_setuni(r->lighting_program, "texture_emits", 1);
 			} else {
-				if ( r->shaders ) {
-					shaderutils_setuni(r->lighting_program, "texture_enabled", 0);
-				} /* else don't enable texturing */
+				if ( r->shaders ) render_placeholder_texture(r);
+				/* else don't glEnable() texturing */
 			}
 		} else if ( p->texture != NULL ) {
 			Texture *texture;
@@ -282,7 +296,6 @@ static int render_model_instance_draw(ModelInstance *instance, Uint32 t, RenderC
 				glBindTexture(GL_TEXTURE_2D, texture->texname);
 				glEnable(GL_TEXTURE_2D);
 				glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
-				if ( r->shaders ) shaderutils_setuni(r->lighting_program, "texture_enabled", 1);
 				if ( r->shaders && texture->has_normals ) {
 					glActiveTexture(GL_TEXTURE1);
 					glBindTexture(GL_TEXTURE_2D, texture->normalmap);
@@ -290,10 +303,10 @@ static int render_model_instance_draw(ModelInstance *instance, Uint32 t, RenderC
 					glActiveTexture(GL_TEXTURE0);
 				}
 			} else {
-				if ( r->shaders ) shaderutils_setuni(r->lighting_program, "texture_enabled", 0);
+				if ( r->shaders ) render_placeholder_texture(r);
 			}
 		} else {
-			if ( r->shaders ) shaderutils_setuni(r->lighting_program, "texture_enabled", 0);
+			if ( r->shaders ) render_placeholder_texture(r);
 		}
 		if ( r->vbos ) {
 			glBindBuffer(GL_ARRAY_BUFFER, p->vertices_buffer);
@@ -623,7 +636,6 @@ void render_draw(Game *game, Uint32 t) {
 		shaderutils_setuni(game->render->lighting_program, "texture", 0); /* GL_TEXTURE0 */
 		shaderutils_setuni(game->render->lighting_program, "normalmap", 1); /* GL_TEXTURE1 */
 		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);
 	}
 	render_setup_lighting(game);