A lot of work

* moved all ugui code to lib/ugui.c3l and made it a library/module
* started work on a sdl3 renderer, with shaders etc
* added the new sdl3.c3l library as a dependency
* makefile is for the renderer

resources/shaders/source/font.frag.glsl

@@ -0,0 +1,18 @@
+#version 330 core
+
+// viewsize.x = viewport width in pixels; viewsize.y = viewport height in pixels
+uniform ivec2 viewsize;
+uniform ivec2 texturesize;
+
+// texture uv coordinate in texture space
+in vec2 uv;
+uniform sampler2DRect ts;
+
+const vec3 textcolor = vec3(1.0, 1.0, 1.0);
+
+
+void main()
+{
+	//gl_FragColor = vec4(1.0f,0.0f,0.0f,1.0f);
+	gl_FragColor = vec4(textcolor, texture(ts, uv));
+}