add piecharts

1 files changed, 87 insertions, 0 deletions

diff --git a/game/src/Game/Theme/PieChart/PieChart.gdshader b/game/src/Game/Theme/PieChart/PieChart.gdshader
new file mode 100644
index 0000000..1707b3d
--- /dev/null
+++ b/game/src/Game/Theme/PieChart/PieChart.gdshader
@@ -0,0 +1,87 @@
+shader_type canvas_item;
+
+// The center in UV coordinates, which will always
+//be 0.5, the actual radius will be controlled by the control node
+//const vec2 center = vec2(0.5,0.5);
+uniform float radius = 0.4;
+
+//shadow
+uniform vec2 shadow_displacement = vec2(0.75,0.75);
+uniform float shadow_tightness = 10;
+uniform float shadow_radius = 0.7;
+uniform float shadow_thickness = 1.0;
+
+// Control of the slices
+uniform float stopAngles[5];
+uniform vec3 colours[5];
+
+// Trim
+uniform vec3 trim_colour;
+uniform float trim_size = 0.05;
+
+// The center is spotlighted by the gradient,
+//control its size and falloff with these
+uniform float gradient_falloff = 3.6;
+uniform float gradient_base = 3.1;
+
+// control whether this is a donut instead of a pie chart
+uniform bool donut = false;
+uniform bool donut_inner_trim = false;
+uniform float donut_inner_radius = 0.15;
+
+// get the polar coordinates of a pixel relative to the center
+vec2 getPolar(vec2 UVin, vec2 center){
+	vec2 relcoord = (UVin-center);
+	float dist = length(relcoord);
+	float theta = PI/2.0 + atan((relcoord.y)/(relcoord.x));
+	if(UVin.x < 0.5){
+		theta += PI;
+	}
+	return vec2(dist,theta);
+}
+
+// from thebookofshaders, returns a gradient falloff
+float parabola( float base, float x, float k ){
+    return pow( base*x*(1.0-x), k );
+}
+
+float parabola_shadow(float base, float x){
+	return base*x*x;
+}
+
+void fragment() {
+	vec2 coords = getPolar(UV,vec2(0.5,0.5));
+	float dist = coords.x;
+	float theta = coords.y;
+
+	vec2 shadow_polar = getPolar(UV,vec2(0.0+shadow_displacement.x,0.0+shadow_displacement.y));
+	float shadow_peak = radius+(radius-donut_inner_radius)/2.0;
+	float shadow_gradient = shadow_thickness+parabola_shadow(shadow_tightness*-10.0,shadow_polar.x+shadow_peak-shadow_radius);
+	
+	// inner hole of the donut => make it transparent
+	if(donut && dist <= donut_inner_radius){
+		COLOR = vec4(0.1,0.1,0.1,shadow_gradient);
+	}
+	// inner trim
+	else if(donut && donut_inner_trim && dist <= donut_inner_radius + trim_size){
+		COLOR = vec4(trim_colour,1.0);
+	}
+	// interior
+	else if(dist <= radius-trim_size){ 
+		for(int i=0;i<stopAngles.length();i++){
+			if(theta <= stopAngles[i]){
+				float gradient = parabola(gradient_base,dist,gradient_falloff);
+				COLOR = vec4(colours[i]*(1.0-gradient),1.0);
+				break;
+			}
+		}
+	}
+	// outer trim
+	else if(dist <= radius){ 
+		COLOR = vec4(trim_colour,1.0);
+	}
+	//outside the circle
+	else{
+		COLOR = vec4(0.1,0.1,0.1,shadow_gradient);
+	}
+}
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