re-add OSD system

src/frontend/qt_sdl/OSD_shaders.h

@@ -0,0 +1,65 @@
+/*
+    Copyright 2016-2020 Arisotura
+
+    This file is part of melonDS.
+
+    melonDS is free software: you can redistribute it and/or modify it under
+    the terms of the GNU General Public License as published by the Free
+    Software Foundation, either version 3 of the License, or (at your option)
+    any later version.
+
+    melonDS is distributed in the hope that it will be useful, but WITHOUT ANY
+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+    FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with melonDS. If not, see http://www.gnu.org/licenses/.
+*/
+
+#ifndef OSD_SHADERS_H
+#define OSD_SHADERS_H
+
+const char* kScreenVS_OSD = R"(#version 140
+
+uniform vec2 uScreenSize;
+
+uniform ivec2 uOSDPos;
+uniform ivec2 uOSDSize;
+
+in vec2 vPosition;
+
+smooth out vec2 fTexcoord;
+
+void main()
+{
+    vec4 fpos;
+
+    vec2 osdpos = (vPosition * vec2(uOSDSize));
+    fTexcoord = osdpos;
+    osdpos += uOSDPos;
+
+    fpos.xy = ((osdpos * 2.0) / uScreenSize) - 1.0;
+    fpos.y *= -1;
+    fpos.z = 0.0;
+    fpos.w = 1.0;
+
+    gl_Position = fpos;
+}
+)";
+
+const char* kScreenFS_OSD = R"(#version 140
+
+uniform sampler2D OSDTex;
+
+smooth in vec2 fTexcoord;
+
+out vec4 oColor;
+
+void main()
+{
+    vec4 pixel = texelFetch(OSDTex, ivec2(fTexcoord), 0);
+    oColor = pixel.bgra;
+}
+)";
+
+#endif // OSD_SHADERS_H