finish platform shader & ball shader

4 files changed, 32 insertions, 1 deletions

diff --git a/assets/ball_f.glsl b/assets/ball_f.glsl
new file mode 100644
index 0000000..e3dfdb3
--- /dev/null
+++ b/assets/ball_f.glsl
@@ -0,0 +1,19 @@
+varying vec4 color;
+varying vec2 pos;
+uniform vec2 center;
+uniform float radius;
+
+void main() {
+	float dist_squared = dot(pos - center, pos - center);
+	float threshold = 0.9 * radius; // radius border starts at
+	float thickness = radius - threshold;
+
+	if (dist_squared > threshold * threshold && dist_squared < radius * radius) {
+		float dist = sqrt(dist_squared);
+		float v = (dist - threshold) / thickness;
+		v = 2.0 * v - 1.0;
+		gl_FragColor = color * (1.0 - v * v);
+	} else {
+		discard;
+	}
+}
diff --git a/assets/ball_v.glsl b/assets/ball_v.glsl
new file mode 100644
index 0000000..7908bc7
--- /dev/null
+++ b/assets/ball_v.glsl
@@ -0,0 +1,9 @@
+varying vec4 color;
+varying vec2 pos;
+uniform mat4 transform;
+
+void main() {
+	gl_Position = transform * gl_Vertex;
+	pos = gl_Vertex.xy;
+	color = gl_Color;
+}
diff --git a/assets/platform_f.glsl b/assets/platform_f.glsl
index 1969a46..82c8740 100644
--- a/assets/platform_f.glsl
+++ b/assets/platform_f.glsl
@@ -5,11 +5,13 @@ uniform float thickness;
 
 void main() {
 	// thanks to https://www.youtube.com/watch?v=PMltMdi1Wzg
+	// (calculates distance to line segment p1-p2)
 	float h = clamp(dot(pos-p1, p2-p1) / dot(p2-p1, p2-p1), 0.0, 1.0);
 	float d = length(pos - p1 - (p2-p1) * h);
 	
 	float v = max(thickness - d, 0.0);
 	v /= thickness;
+	v *= v;
 
 	gl_FragColor = color * v;
 }
diff --git a/assets/platform_v.glsl b/assets/platform_v.glsl
index 472f9df..8f57aab 100644
--- a/assets/platform_v.glsl
+++ b/assets/platform_v.glsl
@@ -4,9 +4,10 @@ varying vec4 color;
 varying vec2 p1, p2;
 varying vec2 pos;
 uniform float thickness;
+uniform mat4 transform;
 
 void main() {
-	gl_Position = gl_Vertex;
+	gl_Position = transform * gl_Vertex;
 	pos = gl_Vertex.xy;
 	color = gl_Color;
 #if 1