missing texture shader

1 files changed, 21 insertions, 0 deletions

diff --git a/shaders/missing_texture.glsl b/shaders/missing_texture.glsl
new file mode 100644
index 0000000..3824ade
--- /dev/null
+++ b/shaders/missing_texture.glsl
@@ -0,0 +1,21 @@
+// missing_texture.glsl
+
+extern float scale = 16.0;
+
+vec4 effect(vec4 color, Image texture, vec2 uv, vec2 screen_coords)
+{
+    vec4 tex = Texel(texture, uv);
+
+    // checker pattern
+    float cx = floor(screen_coords.x / scale);
+    float cy = floor(screen_coords.y / scale);
+
+    float checker = mod(cx + cy, 2.0);
+
+    vec3 magenta = vec3(1.0, 0.0, 1.0);
+    vec3 black   = vec3(0.0, 0.0, 0.0);
+
+    vec3 pattern = mix(magenta, black, checker);
+
+    return vec4(pattern, tex.a) * color;
+}
\ No newline at end of file