More consistent restrictions of display values

4 files changed, 40 insertions, 27 deletions

diff --git a/src/main.cc b/src/main.cc
index a98ca44..8e9fa9a 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -176,7 +176,7 @@ int render() {
 			palette_factor += 1;
 		}
 		if ( palette_factor_decr.wasClicked() ) {
-			palette_factor -= 1;
+			palette_factor = std::max(1, palette_factor-1);
 		}
 
 		if ( window_size_changed ) {
@@ -209,7 +209,7 @@ int render() {
 			{
 				auto guard = collide_shader->use();
 
-				collide_shader->setUniform("show_fluid_quality", display_mode == DisplayMode::QUALITY);
+				collide_shader->setUniform("show_quality", display_mode == DisplayMode::QUALITY);
 				collide_shader->setUniform("iT", iT);
 				iT += 1;
 
@@ -262,18 +262,18 @@ int render() {
 
 			switch ( display_mode ) {
 				case DisplayMode::VELOCITY:
-					scene_shader->setUniform("show_fluid_quality", false);
-					scene_shader->setUniform("show_curl", false);
+					scene_shader->setUniform("show_quality", false);
+					scene_shader->setUniform("show_curl",    false);
 					fluid->draw();
 					break;
 				case DisplayMode::QUALITY:
-					scene_shader->setUniform("show_fluid_quality", true);
-					scene_shader->setUniform("show_curl", false);
+					scene_shader->setUniform("show_quality", true);
+					scene_shader->setUniform("show_curl",    false);
 					fluid->draw();
 					break;
 				case DisplayMode::CURL:
-					scene_shader->setUniform("show_fluid_quality", false);
-					scene_shader->setUniform("show_curl", true);
+					scene_shader->setUniform("show_quality", false);
+					scene_shader->setUniform("show_curl",    true);
 					extra->draw();
 					break;
 			}
diff --git a/src/shader/code/collide.glsl b/src/shader/code/collide.glsl
index 191204e..d32bf78 100644
--- a/src/shader/code/collide.glsl
+++ b/src/shader/code/collide.glsl
@@ -11,7 +11,7 @@ uniform uint nX;
 uniform uint nY;
 uniform uint iT;
 
-uniform bool show_fluid_quality;
+uniform bool show_quality;
 
 /// LBM constants
 
@@ -185,7 +185,7 @@ void main() {
 			d = 1.0;
 		}
 
-		if ( show_fluid_quality ) {
+		if ( show_quality ) {
 			const float approxKn = getLocalKnudsenApproximation(x,y,d,v);
 			setFluidQuality(x,y, approxKn, int(round(log2(approxKn / Kn))));
 		} else {
diff --git a/src/shader/code/extra.glsl b/src/shader/code/extra.glsl
index 5ba6207..3fec976 100644
--- a/src/shader/code/extra.glsl
+++ b/src/shader/code/extra.glsl
@@ -45,8 +45,10 @@ void main() {
 	}
 
 	// simple central difference discretization of the 2d curl operator
-	const float dxvy = (getFluidVelocity(x+1,y).y - getFluidVelocity(x-1,y).y) / (2*convLength);
-	const float dyvx = (getFluidVelocity(x,y+1).x - getFluidVelocity(x,y-1).x) / (2*convLength);
+	const float dxvy = (getFluidVelocity(x+1,y).y - getFluidVelocity(x-1,y).y)
+	                 / (2*convLength);
+	const float dyvx = (getFluidVelocity(x,y+1).x - getFluidVelocity(x,y-1).x)
+	                 / (2*convLength);
 
 	setFluidExtra(x, y,	dxvy - dyvx);
 }
diff --git a/src/shader/code/vertex.glsl b/src/shader/code/vertex.glsl
index 5136023..6ad54cf 100644
--- a/src/shader/code/vertex.glsl
+++ b/src/shader/code/vertex.glsl
@@ -10,13 +10,11 @@ out VS_OUT {
 uniform uint nX;
 uniform uint nY;
 
-uniform bool show_fluid_quality;
+uniform bool show_quality;
 uniform bool show_curl;
 uniform int  palette_factor;
 
-float unit(float x) {
-	return 1.0/(1.0+exp(-x));
-}
+/// Vector utilities
 
 float sq(float x) {
 	return x*x;
@@ -26,6 +24,8 @@ float norm(vec2 v) {
 	return sqrt(sq(v.x)+sq(v.y));
 }
 
+/// Array indexing
+
 vec2 fluidVertexAtIndex(uint i) {
 	const float y = floor(float(i) / float(nX));
 	return vec2(
@@ -34,6 +34,8 @@ vec2 fluidVertexAtIndex(uint i) {
 	);
 }
 
+/// Material number meaning
+
 bool isInactive(int material) {
 	return material == 0;
 }
@@ -42,6 +44,8 @@ bool isWallFrontier(int material) {
 	return material == 2 || material == 3;
 }
 
+/// Data restriction
+
 float restrictedQuality(float quality) {
 	if ( quality < 0.0 ) {
 		return 0.0;
@@ -50,7 +54,17 @@ float restrictedQuality(float quality) {
 	}
 }
 
-vec3 trafficLightPalette(float x) {
+float restrictedCurl(float curl) {
+	if ( abs(curl) < 1.0 ) {
+		return 0.5;
+	} else {
+		return 0.5 + 0.5*min(1.0, curl / (50*palette_factor));
+	}
+}
+
+/// Color palettes
+
+vec3 greenYellowRedPalette(float x) {
 	if ( x < 0.5 ) {
 		return mix(
 			vec3(0.0, 1.0, 0.0),
@@ -98,6 +112,8 @@ vec3 blueRedPalette(float x) {
 	);
 }
 
+/// Actual vertex shader
+
 void main() {
 	const vec2 idx = fluidVertexAtIndex(gl_VertexID);
 
@@ -115,19 +131,14 @@ void main() {
 	} else if ( isWallFrontier(material) ) {
 		vs_out.color = vec3(0.0, 0.0, 0.0);
 	} else {
-		if ( show_fluid_quality ) {
-			vs_out.color = trafficLightPalette(
+		if ( show_quality ) {
+			vs_out.color = greenYellowRedPalette(
 				restrictedQuality(VertexPosition.y)
 			);
 		} else if ( show_curl ) {
-			const float factor = 1.0 / float(100*palette_factor);
-			if ( abs(VertexPosition.x) > 1.0 ) {
-				vs_out.color = blueBlackRedPalette(
-					0.5 + (VertexPosition.x * factor)
-				);
-			} else {
-				vs_out.color = vec3(0.0,0.0,0.0);
-			}
+			vs_out.color = blueBlackRedPalette(
+				restrictedCurl(VertexPosition.x)
+			);
 		} else {
 			vs_out.color = blueRedPalette(
 				norm(VertexPosition.xy) / palette_factor