add gradient rect support

1 files changed, 57 insertions, 0 deletions

diff --git a/render/fx_renderer/gles2/shaders/quad_grad.frag b/render/fx_renderer/gles2/shaders/quad_grad.frag
new file mode 100644
index 0000000..d259942
--- /dev/null
+++ b/render/fx_renderer/gles2/shaders/quad_grad.frag
@@ -0,0 +1,57 @@
+#ifdef GL_FRAGMENT_PRECISION_HIGH
+precision highp float;
+#else
+precision mediump float;
+#endif
+
+varying vec4 v_color;
+varying vec2 v_texcoord;
+
+uniform vec4 colors[LEN];
+uniform vec2 size;
+uniform float degree;
+uniform vec2 grad_box;
+uniform vec2 origin;
+uniform bool linear;
+uniform bool blend;
+uniform int count;
+
+vec4 gradient(){
+	float step;
+
+	vec2 normal = (gl_FragCoord.xy - grad_box)/size;
+	vec2 uv = normal - origin;
+
+	float rad = radians(degree);
+
+	if(linear){
+		float angle = rad + atan(uv.x, uv.y);
+
+		float len = length(uv);
+		uv = vec2(cos(angle) * len, sin(angle) * len) + origin;
+		step = uv.x;
+	} else {
+		vec2 uv = normal - origin;
+		uv = vec2(uv.x * cos(rad) - uv.y * sin(rad),
+				uv.x * sin(rad) + uv.y * cos(rad));
+
+		uv = vec2(-atan(uv.y, uv.x)/3.14159265 * 0.5 + 0.5, 0.0);
+		step = uv.x;
+	}
+
+	float smooth = 1.0/float(count - 1);
+    int ind = int(step/smooth);
+    float at = float(ind)*smooth;
+
+	if(!blend) return colors[ind];
+
+    vec4 color = colors[ind];
+    if(ind > 0) color = mix(colors[ind - 1], color, smoothstep(at - smooth, at, step));
+    if(ind <= count - 1) color = mix(color, colors[ind + 1], smoothstep(at, at + smooth, step));
+
+	return color;
+}
+
+void main(){
+	gl_FragColor = gradient();
+}