JDK-6436942 : OGL: accelerate Gradient/TexturePaint when antialiasing is enabled
  • Type: Bug
  • Component: client-libs
  • Sub-Component: 2d
  • Affected Version: 5.0
  • Priority: P2
  • Status: Resolved
  • Resolution: Fixed
  • OS: solaris_9
  • CPU: generic
  • Submitted: 2006-06-09
  • Updated: 2008-02-06
  • Resolved: 2006-07-17
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JDK 6
6 b92Fixed
Description
Since JDK 5 the OGL-based Java2D pipeline has provided acceleration for GradientPaint
and TexturePaint, but only when antialiasing is disabled.  We should be able to marry
that code with our existing OGLMaskFill code (which currently only handles single
Color antialiased fills) in order to provide acceleration for antialiased
Gradient/TexturePaint fills, as long as the GL_ARB_multitexture extension is
available.
Comments
EVALUATION Attaching four more J2DBench comparison files to this bug report just to show that the benefits are just as compelling on other platforms. The solaris-sparc results are gathered on a SunBlade 2000, 900MHz USIII, XVR-1200. The windows-i586 results are gathered on a 2x 2.8 GHz P4, ATI Radeon 9500 Pro, Catalyst 6.4 drivers. (The results look especially good here because we are essentially working around the slow OGLMaskFill operation, which is pathologically slow on ATI hardware on Windows due to a glDrawPixels() bug that has been filed with, but not yet fixed, by ATI.)
20-06-2006
EVALUATION As described above, we can add two new specialized subclasses of OGLMaskFill: - OGLMaskFill.Solid - OGLMaskFill.Gradient - OGLMaskFill.Texture This mirrors the existing state of affairs in OGLRenderer. We can then refactor the code in OGLRenderer.Gradient/Texture so that the respective OGLMaskFill subclasses can easily call into the enable/disable*Paint() routines to leverage that existing setup code. Finally, we can modify our existing native implementation of OGLMaskFill to do the appropriate multitexturing setup so that we effectively modulate the paint fragments (autogenerated on texture unit 0) with the coverage values from the mask tile (provided on texture unit 1), all of which is modulated with the current color value (which contains the extra alpha value). Perhaps a picture would help, where: Ea = extra alpha Px = gradient/texture paint color (generated for each fragment) Cx = coverage value from mask tile Rx = resulting color/alpha component A R G B primary color Ea Ea Ea Ea (modulated with...) texture unit 0 Pa Pr Pg Pa (modulated with...) texture unit 1 Ca Ca Ca Ca --------------------------------------- resulting color Ra Rr Rg Rb In other words, Ra=Ea*Pa*Ca and so on... I'm attaching the full J2DBench results for solaris-i586 (executed on a Sun W2100z, 2x 2.0 GHz Opteron, Nvidia Quadro FX 1100, 87.11 drivers, Mustang b86). One file (aapaint.solaris-i586.ogl-to-ogl.comp) compares the new OGL performance to the old, here is the summary: ogl.old: Number of tests: 72 Overall average: 224132.19274302718 Best spread: 0.04% variance Worst spread: 12.44% variance (Basis for results comparison) ogl.new: Number of tests: 72 Overall average: 235543.05038378254 Best spread: 0.04% variance Worst spread: 12.18% variance Comparison to basis: Best result: 2542.97% of basis Worst result: 92.45% of basis Number of wins: 44 Number of ties: 20 Number of losses: 8 And the other file (aapaint.solaris-i586.x11-to-ogl.comp) compares the new and old OGL performance to the default (X11-based) pipeline as a baseline, in summary: Summary: x11: Number of tests: 72 Overall average: 43299.88938471539 Best spread: 0.04% variance Worst spread: 83.13% variance (Basis for results comparison) ogl.old: Number of tests: 72 Overall average: 224132.19274302718 Best spread: 0.04% variance Worst spread: 12.44% variance Comparison to basis: Best result: 63904.51% of basis Worst result: 17.15% of basis Number of wins: 40 Number of ties: 0 Number of losses: 32 ogl.new: Number of tests: 72 Overall average: 235543.05038378254 Best spread: 0.04% variance Worst spread: 12.18% variance Comparison to basis: Best result: 68439.2% of basis Worst result: 27.0% of basis Number of wins: 54 Number of ties: 5 Number of losses: 13 The executive summary is (compared to OGL performance in b85): - up to 25x improvement for antialiased TexturePaint operations - 2-7x improvement for antialiased GradientPaint operations - no significant impact on existing accelerated operations
09-06-2006