4 files changed, 129 insertions, 0 deletions
diff --git a/glow/src/shader/compatibility/quad.frag b/glow/src/shader/compatibility/quad.frag
new file mode 100644
index 00000000..c2634c65
--- /dev/null
+++ b/glow/src/shader/compatibility/quad.frag
@@ -0,0 +1,62 @@
+#version 100
+precision mediump float;
+
+uniform float u_ScreenHeight;
+
+varying vec4 v_Color;
+varying vec4 v_BorderColor;
+varying vec2 v_Pos;
+varying vec2 v_Scale;
+varying float v_BorderRadius;
+varying float v_BorderWidth;
+
+float _distance(in vec2 frag_coord, in vec2 position, in vec2 size, float radius)
+{
+    // TODO: Try SDF approach: https://www.shadertoy.com/view/wd3XRN
+    vec2 inner_size = size - vec2(radius, radius) * 2.0;
+    vec2 top_left = position + vec2(radius, radius);
+    vec2 bottom_right = top_left + inner_size;
+
+    vec2 top_left_distance = top_left - frag_coord;
+    vec2 bottom_right_distance = frag_coord - bottom_right;
+
+    vec2 distance = vec2(
+        max(max(top_left_distance.x, bottom_right_distance.x), 0.0),
+        max(max(top_left_distance.y, bottom_right_distance.y), 0.0)
+    );
+
+    return sqrt(distance.x * distance.x + distance.y * distance.y);
+}
+
+void main() {
+    vec2 fragCoord = vec2(gl_FragCoord.x, u_ScreenHeight - gl_FragCoord.y);
+
+    float internal_border = max(v_BorderRadius - v_BorderWidth, 0.0);
+
+    float internal_distance = _distance(
+        fragCoord,
+        v_Pos + vec2(v_BorderWidth),
+        v_Scale - vec2(v_BorderWidth * 2.0),
+        internal_border
+    );
+
+    float border_mix = smoothstep(
+        max(internal_border - 0.5, 0.0),
+        internal_border + 0.5,
+        internal_distance
+    );
+
+    vec4 mixed_color = mix(v_Color, v_BorderColor, border_mix);
+
+    float d = _distance(
+        fragCoord,
+        v_Pos,
+        v_Scale,
+        v_BorderRadius
+    );
+
+    float radius_alpha =
+        1.0 - smoothstep(max(v_BorderRadius - 0.5, 0.0), v_BorderRadius + 0.5, d);
+
+    gl_FragColor = vec4(mixed_color.xyz, mixed_color.w * radius_alpha);
+}
diff --git a/glow/src/shader/compatibility/quad.vert b/glow/src/shader/compatibility/quad.vert
new file mode 100644
index 00000000..0d02e9d0
--- /dev/null
+++ b/glow/src/shader/compatibility/quad.vert
@@ -0,0 +1,46 @@
+#version 100
+
+uniform mat4 u_Transform;
+uniform float u_Scale;
+
+attribute vec2 i_Pos;
+attribute vec2 i_Scale;
+attribute vec4 i_Color;
+attribute vec4 i_BorderColor;
+attribute float i_BorderRadius;
+attribute float i_BorderWidth;
+attribute vec2 q_Pos;
+
+varying vec4 v_Color;
+varying vec4 v_BorderColor;
+varying vec2 v_Pos;
+varying vec2 v_Scale;
+varying float v_BorderRadius;
+varying float v_BorderWidth;
+
+
+void main() {
+    vec2 p_Pos = i_Pos * u_Scale;
+    vec2 p_Scale = i_Scale  * u_Scale;
+
+    float i_BorderRadius = min(
+        i_BorderRadius,
+        min(i_Scale.x, i_Scale.y) / 2.0
+    );
+
+    mat4 i_Transform = mat4(
+        vec4(p_Scale.x + 1.0, 0.0, 0.0, 0.0),
+        vec4(0.0, p_Scale.y + 1.0, 0.0, 0.0),
+        vec4(0.0, 0.0, 1.0, 0.0),
+        vec4(p_Pos - vec2(0.5, 0.5), 0.0, 1.0)
+    );
+
+    v_Color = i_Color;
+    v_BorderColor = i_BorderColor;
+    v_Pos = p_Pos;
+    v_Scale = p_Scale;
+    v_BorderRadius = i_BorderRadius * u_Scale;
+    v_BorderWidth = i_BorderWidth * u_Scale;
+
+    gl_Position = u_Transform * i_Transform * vec4(q_Pos, 0.0, 1.0);
+}
diff --git a/glow/src/shader/compatibility/triangle.frag b/glow/src/shader/compatibility/triangle.frag
new file mode 100644
index 00000000..58fca553
--- /dev/null
+++ b/glow/src/shader/compatibility/triangle.frag
@@ -0,0 +1,8 @@
+#version 100
+precision mediump float;
+
+varying vec4 v_Color;
+
+void main() {
+    gl_FragColor = v_Color;
+}
diff --git a/glow/src/shader/compatibility/triangle.vert b/glow/src/shader/compatibility/triangle.vert
new file mode 100644
index 00000000..975c9781
--- /dev/null
+++ b/glow/src/shader/compatibility/triangle.vert
@@ -0,0 +1,13 @@
+#version 100
+
+uniform mat4 u_Transform;
+
+attribute vec2 i_Position;
+attribute vec4 i_Color;
+
+varying vec4 v_Color;
+
+void main() {
+    v_Color = i_Color;
+    gl_Position = u_Transform * vec4(i_Position, 0.0, 1.0);
+}