Ticket #478: gl-noclear.patch

xpra/client/gl/gl_window_backing.py

@@ -136 +136 @@
         self.texture_size = 0, 0
         self.gl_setup = False
         self.debug_setup = False
+        self.resize = False
         self.paint_screen = False
         self._video_use_swscale = False
         self.draw_needs_refresh = False
@@ -145 +146 @@
         return "GLPixmapBacking(%s, %s, %s)" % (self.wid, self.size, self.pixel_format)
 
     def init(self, w, h):
+        log.info("init(%s, %s) gl_setup=%s", w, h, self.gl_setup)
         #re-init gl projection with new dimensions
         #(see gl_init)
         if self.size!=(w, h):
+            self.resize = (self.size!=(0, 0))
             self.gl_setup = False
             self.size = w, h
 
@@ -224 +227 @@
             self.gl_init_debug()
 
         if not self.gl_setup:
-            self.gl_marker("Initializing GL context for window size %d x %d" % (w, h))
+            self.gl_marker("Initializing GL context for window size %d x %d (resize=%s)" % (w, h, self.resize))
             # Initialize viewport and matrices for 2D rendering
             glViewport(0, 0, w, h)
             glMatrixMode(GL_PROJECTION)
@@ -235 +238 @@
             # glEnableClientState(GL_VERTEX_ARRAY)
             # glEnableClientState(GL_TEXTURE_COORD_ARRAY)
 
+            #if not self.resize:
             # Clear background to transparent black
             glClearColor(0.0, 0.0, 0.0, 0.0)
 
@@ -248 +252 @@
             # Define empty FBO texture and set rendering to FBO
             glEnable(GL_FRAGMENT_PROGRAM_ARB)
             glBindTexture(GL_TEXTURE_RECTANGLE_ARB, self.textures[TEX_FBO])
-            glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, None)
+            if not self.resize:
+                glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, None)
             glBindFramebuffer(GL_FRAMEBUFFER, self.offscreen_fbo)
             glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_RECTANGLE_ARB, self.textures[TEX_FBO], 0)
-            glClear(GL_COLOR_BUFFER_BIT)
+            if not self.resize:
+                glClear(GL_COLOR_BUFFER_BIT)
+            #if not self.resize:
+            #glClearColor(0.0, 0.0, 0.0, 0.0)
 
             # Create and assign fragment programs
             if not self.shaders:
@@ -260 +268 @@
             # Bind program 0 for YUV painting by default
             glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB, self.shaders[YUV2RGB_SHADER])
             self.gl_setup = True
+            self.resize = False
         return drawable
 
     def close(self):