changes

ShaderError.txt

@@ -0,0 +1,24 @@
+#version 330 core
+
+uniform sampler2D tex0;
+in vec2 v_texCoord0;
+
+out vec4 o_color;
+
+void main() {
+    vec2 step = 1.0 / textureSize(tex0, 0);
+    float ref = step(0.5 , texture(tex0, v_texCoord0).r);
+    vec4 outc = vec4(-1.0, -1.0, 0.0, 1.0);
+
+    float contour = 0.0;
+    for (y = -1; y <= 1; ++y) {
+        for (x = -1; x <= 1; ++x) {
+            float smp = step(0.5, texture(tex0, v_texCoord0 + vec2(x,y) * step).r);
+            if (smp != ref) {
+                contour = 1.0;
+            }
+        }
+    }
+
+    o_color = vec4(contour, contour, contour, 1.0);
+}