Bug 1390: Fix GLPixelBuffer.GLPixelAttributes::convert(GL, int, boolean) failure on unsupported GL data format/type

GLPixelBuffer.GLPixelAttributes::convert(GL, int, boolean) failed on unsupported GL data format/type

On Mesa/AMD for GLPBuffer chosen GLCaps used rgba 10/10/10/2
and the GLContext set default values:
GL_IMPLEMENTATION_COLOR_READ_FORMAT: 0x1908 GL_RGBA
GL_IMPLEMENTATION_COLOR_READ_TYPE: 0x8368 GL_UNSIGNED_INT_2_10_10_10_REV

GLPixelBuffer.GLPixelAttributes::getPixelFormat(int format, int type)
currently does not handle the type GL_UNSIGNED_INT_2_10_10_10_REV
and hence returned a null PixelFormat.

Therefor the ctor GLPixelAttributes failed and threw the exception:
"Caught GLException: Could not find PixelFormat for format and/or type:
 PixelAttributes[fmt 0x1908, type 0x8368, null]"

This fix has the GLContext default values pre-validated in the convert(..) method
and to use default GL_RGBA and GL_UNSIGNED_BYTE fallback values if not supported.
This is most important to be future proof.

Later we may shall add these 32bit coding 2+10+10+10 and its reverse.

1 files changed, 17 insertions, 7 deletions

diff --git a/src/jogl/classes/com/jogamp/opengl/util/GLPixelBuffer.java b/src/jogl/classes/com/jogamp/opengl/util/GLPixelBuffer.java
index 0e3497bd4..845c23080 100644
--- a/src/jogl/classes/com/jogamp/opengl/util/GLPixelBuffer.java
+++ b/src/jogl/classes/com/jogamp/opengl/util/GLPixelBuffer.java
@@ -321,14 +321,24 @@ public class GLPixelBuffer {
             } else if( 4 == componentCount || glesReadMode ) {
                 final GLContext ctx = gl.getContext();
                 final int _dFormat = ctx.getDefaultPixelDataFormat();
-                final int dComps = GLBuffers.componentCount(_dFormat);
-                if( dComps == componentCount || 4 == dComps ) { // accept if desired component count or 4 components
-                    dFormat = _dFormat;
-                    dType   = ctx.getDefaultPixelDataType();
-                } else {
-                    dFormat = GL.GL_RGBA;
-                    dType   = GL.GL_UNSIGNED_BYTE;
+                final int _dComps = GLBuffers.componentCount(_dFormat);
+                if( _dComps == componentCount || 4 == _dComps ) { // accept if desired component count or 4 components
+                    // pre-check whether default is supported by implementation
+                    final int _dType = ctx.getDefaultPixelDataType();
+                    final PixelFormat _pixFmt = getPixelFormat(_dFormat, _dType);
+                    if( null != _pixFmt) {
+                        return new GLPixelAttributes(null, _pixFmt, _dFormat, _dType, pack, true);
+                    }
+                    if( GLContext.DEBUG ) {
+                        System.err.println("GLPixelAttributes.convert("+gl.getGLProfile()+", comps "+componentCount+", pack "+pack+
+                                "): GL-impl default unsupported: "+
+                                "[fmt 0x"+Integer.toHexString(_dFormat)+", type 0x"+Integer.toHexString(_dType)+"]: Using std RGBA+UBYTE");
+                        Thread.dumpStack();
+                    }
+                    // fall-through intended to set dFormat/dType to std values
                 }
+                dFormat = GL.GL_RGBA;
+                dType   = GL.GL_UNSIGNED_BYTE;
             } else {
                 return null;
             }