auto-downscale parasite buffers

panda/src/display/graphicsEngine.cxx

@@ -408,15 +408,6 @@ make_output(GraphicsPipe *pipe,
   // last hope.
   
   if (can_use_parasite) {
-    if (x_size > host->get_x_size()) {
-      x_size = Texture::down_to_power_2(host->get_x_size());
-    }
-    if (y_size > host->get_y_size()) {
-      y_size = Texture::down_to_power_2(host->get_y_size());
-    }
-    if (flags & GraphicsPipe::BF_size_square) {
-      x_size = y_size = min(x_size, y_size);
-    }
     ParasiteBuffer *buffer = new ParasiteBuffer(host, name, x_size, y_size, flags);
     buffer->_sort = sort;
     do_add_window(buffer, threading_model);

panda/src/display/graphicsOutput.cxx

@@ -732,13 +732,20 @@ make_texture_buffer(const string &name, int x_size, int y_size,
   FrameBufferProperties props;
   props.set_rgb_color(1);
   props.set_depth_bits(1);
+
+  int flags = GraphicsPipe::BF_refuse_window;
+  if (textures_power_2 != ATS_none) {
+    flags |= GraphicsPipe::BF_size_power_2;
+  }
+  if (tex->get_texture_type() == Texture::TT_cube_map) {
+    flags |= GraphicsPipe::BF_size_square;
+  }
   
   GraphicsOutput *buffer = get_gsg()->get_engine()->
     make_output(get_gsg()->get_pipe(),
                 name, get_child_sort(),
                 props, WindowProperties::size(x_size, y_size),
-                GraphicsPipe::BF_refuse_window,
-                get_gsg(), get_host());
+                flags, get_gsg(), get_host());
 
   if (buffer != (GraphicsOutput *)NULL) {
     buffer->add_render_texture(tex, to_ram ? RTM_copy_ram : RTM_bind_or_copy);

panda/src/display/graphicsPipe.h

@@ -85,6 +85,7 @@ PUBLISHED:
     BF_rtt_cumulative      = 0x0400, // Buffer supports cumulative render-to-texture.
     BF_fb_props_optional   = 0x0800, // FrameBufferProperties can be ignored.
     BF_size_square         = 0x1000, // x_size must equal y_size (e.g. for cube maps)
+    BF_size_power_2        = 0x2000, // x_size and y_size must each be a power of two
   };
 
   INLINE bool is_valid() const;

panda/src/display/parasiteBuffer.cxx

@@ -12,8 +12,8 @@
 //
 ////////////////////////////////////////////////////////////////////
 
-
 #include "parasiteBuffer.h"
+#include "texture.h"
 
 TypeHandle ParasiteBuffer::_type_handle;
 
@@ -87,6 +87,24 @@ set_size(int x, int y) {
   set_size_and_recalc(x, y);
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: ParasiteBuffer::set_size_and_recalc
+//       Access: Public
+//  Description: 
+////////////////////////////////////////////////////////////////////
+void ParasiteBuffer::
+set_size_and_recalc(int x, int y) {
+  if (_creation_flags & GraphicsPipe::BF_size_power_2) {
+    x = Texture::down_to_power_2(x);
+    y = Texture::down_to_power_2(y);
+  }
+  if (_creation_flags & GraphicsPipe::BF_size_square) {
+    x = y = min(x, y);
+  }
+
+  GraphicsOutput::set_size_and_recalc(x, y);
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: ParasiteBuffer::is_active
 //       Access: Published, Virtual
@@ -135,6 +153,12 @@ begin_frame(FrameMode mode, Thread *current_thread) {
       set_size_and_recalc(_host->get_x_size(),
                           _host->get_y_size());
     }
+  } else {
+    if (_host->get_x_size() < _x_size ||
+        _host->get_y_size() < _y_size) {
+      set_size_and_recalc(min(_x_size, _host->get_x_size()),
+                          min(_y_size, _host->get_y_size()));
+    }
   }
   
   clear_cube_map_selection();

panda/src/display/parasiteBuffer.h

@@ -60,6 +60,7 @@ PUBLISHED:
   void set_size(int x, int y);
 
 public:
+  void set_size_and_recalc(int x, int y);
   virtual bool begin_frame(FrameMode mode, Thread *current_thread);
   virtual void end_frame(FrameMode mode, Thread *current_thread);
   virtual GraphicsOutput *get_host();