Backported llimage changes from Viewer 2.0.0

1 files changed, 46 insertions, 4 deletions

diff --git a/linden/indra/llimage/llimagej2c.cpp b/linden/indra/llimage/llimagej2c.cpp
index 1aae83e..5480c88 100644
--- a/linden/indra/llimage/llimagej2c.cpp
+++ b/linden/indra/llimage/llimagej2c.cpp
@@ -3,7 +3,7 @@
  *
  * $LicenseInfo:firstyear=2001&license=viewergpl$
  * 
- * Copyright (c) 2001-2009, Linden Research, Inc.
+ * Copyright (c) 2001-2010, Linden Research, Inc.
  * 
  * Second Life Viewer Source Code
  * The source code in this file ("Source Code") is provided by Linden Lab
@@ -178,8 +178,8 @@ LLImageJ2C::LLImageJ2C() : 	LLImageFormatted(IMG_CODEC_J2C),
                                                         mMaxBytes(0),
                                                         mRawDiscardLevel(-1),
                                                         mRate(0.0f),
-                                                        mReversible(FALSE)
-        
+                                                        mReversible(FALSE),
+                                                        mAreaUsedForDataSizeCalcs(0)
 {
         //We assume here that if we wanted to create via
         //a dynamic library that the approriate open calls were made
@@ -195,6 +195,12 @@ LLImageJ2C::LLImageJ2C() : 	LLImageFormatted(IMG_CODEC_J2C),
         }
 
         mImpl = j2cimpl_create_func();
+
+        // Clear data size table
+        for( S32 i = 0; i <= MAX_DISCARD_LEVEL; i++)
+        {       // Array size is MAX_DISCARD_LEVEL+1
+                mDataSizes[i] = 0;
+        }
 }
 
 // virtual
@@ -368,9 +374,45 @@ S32 LLImageJ2C::calcHeaderSize()
         return calcHeaderSizeJ2C();
 }
 
+
+// calcDataSize() returns how many bytes to read 
+// to load discard_level (including header and higher discard levels)
 S32 LLImageJ2C::calcDataSize(S32 discard_level)
 {
-        return calcDataSizeJ2C(getWidth(), getHeight(), getComponents(), discard_level, mRate);
+        discard_level = llclamp(discard_level, 0, MAX_DISCARD_LEVEL);
+
+        if ( mAreaUsedForDataSizeCalcs != (getHeight() * getWidth()) 
+                || mDataSizes[0] == 0)
+        {
+                mAreaUsedForDataSizeCalcs = getHeight() * getWidth();
+                
+                S32 level = MAX_DISCARD_LEVEL;  // Start at the highest discard
+                while ( level >= 0 )
+                {
+                        mDataSizes[level] = calcDataSizeJ2C(getWidth(), getHeight(), getComponents(), level, mRate);
+                        level--;
+                }
+
+                /* This is technically a more correct way to calculate the size required
+                   for each discard level, since they should include the size needed for
+                   lower levels.   Unfortunately, this doesn't work well and will lead to 
+                   download stalls.  The true correct way is to parse the header.  This will
+                   all go away with http textures at some point.
+
+                // Calculate the size for each discard level.   Lower levels (higher quality)
+                // contain the cumulative size of higher levels         
+                S32 total_size = calcHeaderSizeJ2C();
+
+                S32 level = MAX_DISCARD_LEVEL;  // Start at the highest discard
+                while ( level >= 0 )
+                {       // Add in this discard level and all before it
+                        total_size += calcDataSizeJ2C(getWidth(), getHeight(), getComponents(), level, mRate);
+                        mDataSizes[level] = total_size;
+                        level--;
+                }
+                */
+        }
+        return mDataSizes[discard_level];
 }
 
 S32 LLImageJ2C::calcDiscardLevelBytes(S32 bytes)