imgui sort of works!

src/game/rendering/fs_imgui_image.sc

@@ -0,0 +1,21 @@
+$input v_texcoord0
+
+/*
+ * Copyright 2014 Dario Manesku. All rights reserved.
+ * License: https://github.com/bkaradzic/bgfx/blob/master/LICENSE
+ */
+
+#include <bgfx_shader.sh>
+
+uniform vec4 u_imageLodEnabled;
+SAMPLER2D(s_texColor, 0);
+
+#define u_imageLod     u_imageLodEnabled.x
+#define u_imageEnabled u_imageLodEnabled.y
+
+void main()
+{
+	vec3 color = texture2DLod(s_texColor, v_texcoord0, u_imageLod).xyz;
+	float alpha = 0.2 + 0.8*u_imageEnabled;
+	gl_FragColor = vec4(color, alpha);
+}