Tuning options

Here are the Marlin tuning options using following system properties:

• -Dsun.java2d.renderer.useThreadLocal=true|false (true by default): allow marlin to use ThreadLocal (TL) variables (true) or ConcurrentLinkedQueue (CLQ) (false) to store its rendering context (one per concurrent rendering thread). TL are 10% faster but may waste memory in web server environnement (high number of threads so many contexts)
• -Dsun.java2d.renderer.pixelsize=2048 (2048 by default): adjust initial capacity of rendering arrays depending on the typical image size/width (in fact largest shape's area). If you are drawing very large images (high resolution maps), please set this setting to your 'average' map size (4096x4096 or more ...); but do not set it too high to avoid wasting unused memory ...

FYI, the typical size per RenderingContext is 512K (pixelsize=2048) and 1Mb for pixelsize=4096 ...

For example to use CLQ mode (web server) optimized for large image rendering: java -Xbootclasspath/a:[path]/marlin-x.y.jar -Dsun.java2d.renderer.useThreadLocal=false -Dsun.java2d.renderer.pixelsize=8192 -Dsun.java2d.renderer=org.marlin.pisces.MarlinRenderingEngine ...

Advanced settings:

The Marlin renderer has many (internal) settings for tuning, debugging & quality:

INFO: ===============================================================================
INFO: Marlin software rasterizer           = ENABLED
INFO: Version                              = [marlin-0.7.5-Unsafe]
INFO: sun.java2d.renderer                  = org.marlin.pisces.MarlinRenderingEngine
INFO: sun.java2d.renderer.useThreadLocal   = true
INFO: sun.java2d.renderer.useRef           = soft
INFO: sun.java2d.renderer.edges            = 4096
INFO: sun.java2d.renderer.pixelsize        = 2048
INFO: sun.java2d.renderer.subPixel_log2_X  = 3
INFO: sun.java2d.renderer.subPixel_log2_Y  = 3
INFO: sun.java2d.renderer.tileSize_log2    = 5
INFO: sun.java2d.renderer.tileWidth_log2   = 5
INFO: sun.java2d.renderer.blockSize_log2   = 5
INFO: sun.java2d.renderer.forceRLE         = false
INFO: sun.java2d.renderer.forceNoRLE       = false
INFO: sun.java2d.renderer.useTileFlags     = true
INFO: sun.java2d.renderer.useTileFlags.useHeuristics = true
INFO: sun.java2d.renderer.rleMinWidth      = 64
INFO: sun.java2d.renderer.useSimplifier    = false
INFO: sun.java2d.renderer.clip.curves      = false
INFO: sun.java2d.renderer.doStats          = false
INFO: sun.java2d.renderer.doMonitors       = false
INFO: sun.java2d.renderer.doChecks         = false
INFO: sun.java2d.renderer.useLogger        = false
INFO: sun.java2d.renderer.logCreateContext = false
INFO: sun.java2d.renderer.logUnsafeMalloc  = false
INFO: sun.java2d.renderer.cubic_dec_d2     = 1.0
INFO: sun.java2d.renderer.cubic_inc_d1     = 0.4
INFO: sun.java2d.renderer.quad_dec_d2      = 0.5
INFO: Renderer settings:
INFO: CUB_DEC_BND  = 8.0
INFO: CUB_INC_BND  = 3.2
INFO: QUAD_DEC_BND = 4.0
INFO: INITIAL_EDGES_CAPACITY               = 98304
INFO: INITIAL_CROSSING_COUNT               = 1024
INFO: ===============================================================================

In short:

• useRef [hard|soft|weak] controls how renderer contexts are kept in cache: GC clears weak references quite fast, soft only if OOM occurs and hard reference are never cleaned up.
• subPixel_log2_X/Y ~ subpixel number: 3 means 2^3 ie 8x8 subpixels, 2 means 2^2 ie 4x4 subpixels and 4 means 16x16 (slower)
• tileSize/tileWidth_log2 ~ tile height/width: 5 means 2^5 ie 32x32 tiles. You can try increasing it up to 256x256 (8) and use asymetric tiles 32x128
• doChecks is useful for debugging purposes to check internal array
• doStats may help gathering rendering statistics that are logged when the JVM exits (shutdown hook)