moved all shader code out of C++ source and into external shader files

General code cleanup and easier maintenance.

app/shaders/alphaover.frag

@@ -0,0 +1,15 @@
+#version 110
+
+varying vec2 ove_texcoord;
+
+uniform sampler2D base_in;
+uniform sampler2D blend_in;
+
+void main(void) {
+  vec4 base_col = texture2D(base_in, ove_texcoord);
+  vec4 blend_col = texture2D(blend_in, ove_texcoord);
+  base_col *= 1.0 - blend_col.a;
+  base_col += blend_col;
+  
+  gl_FragColor = base_col;
+}

app/shaders/crossdissolve.frag

@@ -0,0 +1,15 @@
+#version 110
+
+varying vec2 ove_texcoord;
+
+uniform sampler2D base_in;
+uniform sampler2D blend_in;
+
+void main(void) {
+  vec4 base_col = texture2D(base_in, ove_texcoord);
+  vec4 blend_col = texture2D(blend_in, ove_texcoord);
+  base_col *= 1.0 - blend_col.a;
+  base_col += blend_col;
+  
+  gl_FragColor = base_col;
+}

app/shaders/opacity.frag

@@ -0,0 +1,10 @@
+#version 110
+
+varying vec2 ove_tex_coord;
+
+uniform sampler2D tex_in;
+uniform float opacity_in;
+
+void main(void) {
+  gl_FragColor = texture2D(tex_in, ove_tex_coord) * (opacity_in * 0.01);
+}

app/shaders/shaders.qrc

@@ -1,5 +1,9 @@
 <RCC>
     <qresource prefix="/shaders">
+        <file>alphaover.frag</file>
+        <file>crossdissolve.frag</file>
+        <file>opacity.frag</file>
+        <file>solid.frag</file>
         <file>videoinput.frag</file>
         <file>videoinput.vert</file>
     </qresource>

app/shaders/solid.frag

@@ -0,0 +1,7 @@
+#version 110
+
+uniform vec4 color_in;
+
+void main(void) {
+  gl_FragColor = color_in;
+}