From d66bd9714e1e1af4267fb4eb208143a070e65ee3 Mon Sep 17 00:00:00 2001
From: Zhigang Gong <zhigang.gong@gmail.com>
Date: Thu, 11 Aug 2011 09:54:28 -0400
Subject: [PATCH] glamor: Concentrate FBO's creation to one function.

And add status checking for it.

Signed-off-by: Zhigang Gong <zhigang.gong@gmail.com>
---
 glamor/glamor.c        |  9 +--------
 glamor/glamor_pixmap.c | 43 +++++++++++++++++++++++++++++++++---------
 glamor/glamor_priv.h   | 14 ++++++++++++++
 3 files changed, 49 insertions(+), 17 deletions(-)

diff --git a/glamor/glamor.c b/glamor/glamor.c
index eeb85f23a..dd0d69db7 100644
--- a/glamor/glamor.c
+++ b/glamor/glamor.c
@@ -74,14 +74,7 @@ glamor_set_pixmap_texture(PixmapPtr pixmap, int w, int h, unsigned int tex)
      */
     pixmap_priv->gl_fbo = 1;
     pixmap_priv->gl_tex = 1;
-    glGenFramebuffers(1, &pixmap_priv->fb);
-    glBindFramebuffer(GL_FRAMEBUFFER, pixmap_priv->fb);
-    glFramebufferTexture2D(GL_FRAMEBUFFER,
-                             GL_COLOR_ATTACHMENT0,
-                             GL_TEXTURE_2D,
-                             pixmap_priv->tex,
-                             0);
-
+    glamor_pixmap_ensure_fb(pixmap);
     screen->ModifyPixmapHeader(pixmap, w, h, 0, 0,
                               (((w * pixmap->drawable.bitsPerPixel +
                                  7) / 8) + 3) & ~3,
diff --git a/glamor/glamor_pixmap.c b/glamor/glamor_pixmap.c
index 5dd59756d..d747ade43 100644
--- a/glamor/glamor_pixmap.c
+++ b/glamor/glamor_pixmap.c
@@ -359,6 +359,39 @@ _glamor_upload_pixmap_to_texture(PixmapPtr pixmap, GLenum format, GLenum type, i
   glBindFramebuffer(GL_FRAMEBUFFER, 0);
 }
 
+void
+glamor_pixmap_ensure_fb(PixmapPtr pixmap)
+{
+  int status;
+  glamor_pixmap_private *pixmap_priv = glamor_get_pixmap_private(pixmap);
+  if (pixmap_priv->fb == 0)
+    glGenFramebuffers(1, &pixmap_priv->fb);
+  assert(pixmap_priv->tex != 0);
+  glBindFramebuffer(GL_FRAMEBUFFER, pixmap_priv->fb);
+  glFramebufferTexture2D(GL_FRAMEBUFFER,
+                         GL_COLOR_ATTACHMENT0,
+			 GL_TEXTURE_2D,
+			 pixmap_priv->tex,
+			 0);
+    status = glCheckFramebufferStatus (GL_FRAMEBUFFER);
+    if (status != GL_FRAMEBUFFER_COMPLETE) {
+        const char *str;
+        switch (status) {
+        case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT: str= "incomplete attachment"; break;
+        case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT: str= "incomplete/missing attachment"; break;
+        case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER: str= "incomplete draw buffer"; break;
+        case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER: str= "incomplete read buffer"; break;
+        case GL_FRAMEBUFFER_UNSUPPORTED: str= "unsupported"; break;
+        case GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE: str= "incomplete multiple"; break;
+        default: str = "unknown error"; break;
+        }
+
+        LogMessageVerb(X_INFO, 0,
+                 "destination is framebuffer incomplete: %s [%#x]\n",
+                 str, status);
+        assert(0);
+    }
+}
 
 /*  
  * Prepare to upload a pixmap to texture memory.
@@ -393,21 +426,13 @@ glamor_pixmap_upload_prepare(PixmapPtr pixmap, int ax)
     glGenTextures(1, &pixmap_priv->tex);
 
   if (need_fbo) {
-    if (pixmap_priv->fb == 0) 
-      glGenFramebuffers(1, &pixmap_priv->fb);
     glBindTexture(GL_TEXTURE_2D, pixmap_priv->tex);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, pixmap->drawable.width, 
 		 pixmap->drawable.height, 0,
 		 GL_RGBA, GL_UNSIGNED_BYTE, NULL);
-
-    glBindFramebuffer(GL_FRAMEBUFFER, pixmap_priv->fb);
-    glFramebufferTexture2D(GL_FRAMEBUFFER,
-			      GL_COLOR_ATTACHMENT0,
-			      GL_TEXTURE_2D,
-			      pixmap_priv->tex,
-			      0);
+    glamor_pixmap_ensure_fb(pixmap);
   }
  
   return 0;
diff --git a/glamor/glamor_priv.h b/glamor/glamor_priv.h
index c04e118ed..bf032b1cb 100644
--- a/glamor/glamor_priv.h
+++ b/glamor/glamor_priv.h
@@ -62,6 +62,10 @@
 #define GL_PACK_ROW_LENGTH                      0x0D02
 #define GL_UNPACK_ROW_LENGTH                    0x0CF2
 
+#define GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER 0x8CDB
+#define GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER 0x8CDC
+#define GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE 0x8D56
+
 #define GLEW_MESA_pack_invert             0
 #define GL_PACK_INVERT_MESA               0x8758
 
@@ -802,6 +806,16 @@ glamor_download_pixmap_to_cpu(PixmapPtr pixmap, glamor_access_t access);
  **/
 void
 glamor_restore_pixmap_to_texture(PixmapPtr pixmap);
+/**
+ * Ensure to have a fbo attached to the pixmap. 
+ * If the pixmap already has one fbo then do nothing.
+ * Otherwise, it will generate a new fbo, and bind
+ * the pixmap's texture to the fbo. 
+ * The pixmap must has a valid texture before call this
+ * API, othersie, it will trigger a assert.
+ */
+void
+glamor_pixmap_ensure_fb(PixmapPtr pixmap);
 
 /**
  * Upload a pixmap to gl texture. Used by dynamic pixmap