Make the recharge ripple fade nicely

git-svn-id: svn://cook.msm.cam.ac.uk:745/thrust3d/thrust3d@144 84d2e878-0bd5-11dd-ad15-13eda11d74c5

5 files changed, 40 insertions, 15 deletions

diff --git a/data/shaders/swirlytron.frag b/data/shaders/swirlytron.frag
index 81c80c3..7d8aaec 100644
--- a/data/shaders/swirlytron.frag
+++ b/data/shaders/swirlytron.frag
@@ -12,26 +12,28 @@
 varying vec2 coords;
 varying vec2 incoords;
 uniform float time;
+uniform float rrb;		/* Recharge ripple brightness */
 uniform bool rechargeripple;
 
 void main() {
 	
 	vec3 colour;
-	float f;
-	float r;
 	
-	r = pow(abs(coords.x), 2.0) + pow(abs(coords.y), 2.0);
-	f = 1.0;
 	colour.r = 0.0;
 	colour.g = 0.0;
-	colour.b = 1.0 * cos(2*f*3.141*r - (time/250.0) );
+	colour.b = 0.5*max(0.0, cos(2*3.141*coords.x-(time/250.0))) + 0.5*max(0.0, cos(2*3.141*coords.y-(time/250.0)));
 
 	if ( rechargeripple ) {
+		
+		const float f = 1.0;
+		float r;
+		
 		r = pow(abs(incoords.x), 2.0) + pow(abs(incoords.y), 2.0);
-		f = 1.0;
-		colour.r += 0.8 * cos(2*f*3.141*r + (time/250.0) );
-		colour.g += 0.3 * cos(2*f*3.141*r + (time/250.0) );
-		colour.b += 0.1;
+		
+		colour.r += rrb * 0.8 * cos(2*f*3.141*r + (time/250.0) );
+		colour.g += rrb * 0.3 * cos(2*f*3.141*r + (time/250.0) );
+		colour.b += rrb * 0.1;
+		
 	}
 	
 	gl_FragColor = vec4(colour.r, colour.g, colour.b, 1.0);
diff --git a/src/game.c b/src/game.c
index c51dd7f..a155c69 100644
--- a/src/game.c
+++ b/src/game.c
@@ -252,6 +252,7 @@ Game *game_new(int width, int height, GameOptions gameopts) {
 	g->radiation = 0.1;
 	g->platform_rel_x = 0.0;
 	g->platform_rel_y = 0.0;
+	g->time_of_landing_event = -1500.0;	/* Force the platform recharge ripple to be 'bright' */
 		
 	/* Renderer setup */
 	g->render = render_setup(width, height, gameopts.disable_vbos, gameopts.disable_fbos, gameopts.disable_shaders);
diff --git a/src/physics.c b/src/physics.c
index ad2dae6..4575b88 100644
--- a/src/physics.c
+++ b/src/physics.c
@@ -316,6 +316,7 @@ static void physics_process(ModelInstance *obj, Uint32 dt, Game *game) {
 					obj->recharging = 1;
 					game->platform_rel_x = coll.obj->x - obj->x;
 					game->platform_rel_y = coll.obj->y - obj->y;
+					game->time_of_landing_event = game->tlast + sttc;
 				}
 				
 			} else {
@@ -357,7 +358,10 @@ void physics_step(Game *game, Uint32 t) {
 			game->lander->vz += THRUST * dt;
 			game->fuel -= 0.0002;
 			game->lander->landed = 0;
-			game->lander->recharging = 0;
+			if ( game->lander->recharging ) {
+				game->time_of_landing_event = game->tlast + dt;
+				game->lander->recharging = 0;
+			}
 		}
 	}
 	if ( game->forward && !game->lander->landed ) {
diff --git a/src/render.c b/src/render.c
index 044dd42..e18b3a6 100644
--- a/src/render.c
+++ b/src/render.c
@@ -643,11 +643,28 @@ void render_draw(Game *game, Uint32 t) {
 		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, r->swirly_fbo);
 		glClear(GL_COLOR_BUFFER_BIT);
 		glViewport(0, 0, 64, 64);
-		if ( r->shaders ) glUseProgram(r->swirly_program);
-		if ( r->shaders ) glUniform1f(glGetUniformLocation(game->render->swirly_program, "time"), t);
-		if ( r->shaders ) glUniform1i(glGetUniformLocation(game->render->swirly_program, "landed"), game->lander->recharging);
-		if ( r->shaders ) glUniform1i(glGetUniformLocation(game->render->swirly_program, "rechargeripple"), game->lander->recharging);
-		if ( r->shaders ) glUniform2f(glGetUniformLocation(game->render->swirly_program, "lander"), game->platform_rel_x, game->platform_rel_y);
+		if ( r->shaders ) {
+			
+			GLfloat rrb = 0.0;
+		
+			glUseProgram(r->swirly_program);
+			glUniform1f(glGetUniformLocation(game->render->swirly_program, "time"), t);
+			glUniform1i(glGetUniformLocation(game->render->swirly_program, "landed"), game->lander->recharging);
+			if ( game->lander->recharging ) {
+				/* Fade in */
+				rrb = fminf(((GLfloat)t-game->time_of_landing_event)/1500.0, 1.0);
+				glUniform1i(glGetUniformLocation(game->render->swirly_program, "rechargeripple"), 1);
+			} else if ( game->time_of_landing_event - t < 750 ) {
+				/* Fade out */
+				rrb = fmaxf(1.0 - ((GLfloat)t-game->time_of_landing_event)/750.0, 0.0);
+				glUniform1i(glGetUniformLocation(game->render->swirly_program, "rechargeripple"), 1);
+			} else {
+				glUniform1i(glGetUniformLocation(game->render->swirly_program, "rechargeripple"), 0);
+			}
+			glUniform1f(glGetUniformLocation(game->render->swirly_program, "rrb"), rrb);
+			glUniform2f(glGetUniformLocation(game->render->swirly_program, "lander"), game->platform_rel_x, game->platform_rel_y);
+			
+		} /* else this is all a little pointless... */
 		glMatrixMode(GL_PROJECTION);
 		glLoadIdentity();
 		glMatrixMode(GL_MODELVIEW);
diff --git a/src/types.h b/src/types.h
index 928493e..bfbe36a 100644
--- a/src/types.h
+++ b/src/types.h
@@ -256,6 +256,7 @@ typedef struct {
 	
 	GLfloat		platform_rel_x;
 	GLfloat		platform_rel_y;
+	GLfloat		time_of_landing_event;
 		
 } Game;