ported the University CGI demo from WINDOWS + GLUT + GLEW + GLU + OpenGL 4 to LINUX WAYLAND + EGL + GLES 2 with minimal cuts

GL_STUFF/SOURCES/EFFECTS/TEX_MERGER/fragmentShader_merger.glsl

@@ -0,0 +1,27 @@
+#version 300 es
+
+/*this will affect all the float guys (float, vecN, matN )*/
+precision mediump float;
+
+
+in vec3 fragPos;
+in vec2 frag_uv;  //coordinate 2d di texure
+
+uniform sampler2D inTex1;   //campionatore 2d 
+uniform sampler2D inTex2;
+out vec4 FragColor;  
+
+vec4 max4(vec4 a, vec4 b){
+    return vec4( max(a.x, b.x), max(a.y, b.y), max(a.z, b.z), max(a.w, b.w));
+}
+
+void main()
+{   
+
+	float mergeFac = 0.6;
+	float adjFac = 1.5;
+    //FragColor = vec4(1.0f, 1.0f, 0, 1);
+    FragColor = mix(texture(inTex1, frag_uv), texture(inTex2, frag_uv), mergeFac);
+	FragColor = vec4( clamp( 0, 1, adjFac * FragColor.x), clamp( 0, 1, adjFac * FragColor.y), clamp( 0, 1, adjFac * FragColor.z), clamp( 0, 1, adjFac * FragColor.w));
+    //FragColor = 0.25 * texture(inTex1, frag_uv) + 0.75 * texture(inTex2, frag_uv);//max4(texture(inTex1, frag_uv) , texture(inTex2, frag_uv));
+}