Feature: #183 custom window shader & #193 --no-fading-destroyed-argb

- Add --glx-fshader-win, which specifies a custom fragment shader for
  painting windows. compton-default-fshader-win.glsl is the shader with
  default behavior, and compton-fake-transparency-fshader-win.glsl
  provides a template of fake transparency. (#183)

- Add --force-win-blend to force all windows to be painted with
  blending.

- Add --no-fading-destroyed-argb, as a workaround of bugs in some WMs.
  (#193)

1 files changed, 22 insertions, 5 deletions

diff --git a/compton.h b/compton.h
index 7eff0a390..524e81ed9 100644
--- a/compton.h
+++ b/compton.h
@@ -675,20 +675,37 @@ static win *
 paint_preprocess(session_t *ps, win *list);
 
 static void
-render(session_t *ps, int x, int y, int dx, int dy, int wid, int hei,
+render_(session_t *ps, int x, int y, int dx, int dy, int wid, int hei,
     double opacity, bool argb, bool neg,
     Picture pict, glx_texture_t *ptex,
-    XserverRegion reg_paint, const reg_data_t *pcache_reg);
+    XserverRegion reg_paint, const reg_data_t *pcache_reg
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+    , const glx_prog_main_t *pprogram
+#endif
+    );
+
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+#define \
+   render(ps, x, y, dx, dy, wid, hei, opacity, argb, neg, pict, ptex, reg_paint, pcache_reg, pprogram) \
+  render_(ps, x, y, dx, dy, wid, hei, opacity, argb, neg, pict, ptex, reg_paint, pcache_reg, pprogram)
+#else
+#define \
+   render(ps, x, y, dx, dy, wid, hei, opacity, argb, neg, pict, ptex, reg_paint, pcache_reg, pprogram) \
+  render_(ps, x, y, dx, dy, wid, hei, opacity, argb, neg, pict, ptex, reg_paint, pcache_reg)
+#endif
 
 static inline void
-win_render(session_t *ps, win *w, int x, int y, int wid, int hei, double opacity, XserverRegion reg_paint, const reg_data_t *pcache_reg, Picture pict) {
+win_render(session_t *ps, win *w, int x, int y, int wid, int hei,
+    double opacity, XserverRegion reg_paint, const reg_data_t *pcache_reg,
+    Picture pict) {
   const int dx = (w ? w->a.x: 0) + x;
   const int dy = (w ? w->a.y: 0) + y;
-  const bool argb = (w && w->mode == WMODE_ARGB);
+  const bool argb = (w && (WMODE_ARGB == w->mode || ps->o.force_win_blend));
   const bool neg = (w && w->invert_color);
 
   render(ps, x, y, dx, dy, wid, hei, opacity, argb, neg,
-      pict, (w ? w->paint.ptex: ps->root_tile_paint.ptex), reg_paint, pcache_reg);
+      pict, (w ? w->paint.ptex: ps->root_tile_paint.ptex),
+      reg_paint, pcache_reg, (w ? &ps->o.glx_prog_win: NULL));
 }
 
 static inline void