util: Add callback to fetch a single pixel.

progs/gallium/unit/u_format_test.c

@@ -33,6 +33,37 @@
 #include "util/u_format_tests.h"
 
 
+static boolean
+test_format_fetch_float(const struct util_format_description *format_desc,
+                        const struct util_format_test_case *test)
+{
+   float unpacked[4];
+   unsigned i;
+   boolean success;
+
+   /*
+    * TODO: test block formats too.
+    */
+   if (format_desc->block.width != 1 && format_desc->block.height != 1) {
+     return TRUE;
+   }
+
+   format_desc->fetch_float(unpacked, test->packed, 0, 0);
+
+   success = TRUE;
+   for (i = 0; i < 4; ++i)
+      if (test->unpacked[i] != unpacked[i])
+         success = FALSE;
+
+   if (!success) {
+      printf("FAILED: (%f %f %f %f) obtained\n", unpacked[0], unpacked[1], unpacked[2], unpacked[3]);
+      printf("        (%f %f %f %f) expected\n", test->unpacked[0], test->unpacked[1], test->unpacked[2], test->unpacked[3]);
+   }
+
+   return success;
+}
+
+
 static boolean
 test_format_unpack_float(const struct util_format_description *format_desc,
                          const struct util_format_test_case *test)
@@ -225,6 +256,9 @@ test_all(void)
 {
    bool success = TRUE;
 
+   if (!test_one(&test_format_fetch_float, "fetch_float"))
+     success = FALSE;
+
    if (!test_one(&test_format_pack_float, "pack_float"))
      success = FALSE;
 

src/gallium/auxiliary/util/u_format.h

@@ -191,21 +191,34 @@ struct util_format_description
    enum util_format_colorspace colorspace;
 
    /**
-    * Accessor functions.
+    * Unpack a span of pixel blocks to R8G8B8A8_UNORM.
     */
-
    void
    (*unpack_8unorm)(uint8_t *dst, const uint8_t *src, unsigned nr_blocks);
 
+   /**
+    * Pack a span of pixel blocks from R8G8B8A8_UNORM.
+    */
    void
    (*pack_8unorm)(uint8_t *dst, const uint8_t *src, unsigned nr_blocks);
 
+   /**
+    * Unpack a span of pixel blocks to R32G32B32A32_FLOAT.
+    */
    void
    (*unpack_float)(float *dst, const uint8_t *src, unsigned nr_blocks);
 
+   /**
+    * Pack a span of pixel blocks from R32G32B32A32_FLOAT.
+    */
    void
    (*pack_float)(uint8_t *dst, const float *src, unsigned nr_blocks);
 
+   /**
+    * Fetch a single pixel (i, j) from a block.
+    */
+   void
+   (*fetch_float)(float *dst, const uint8_t *src, unsigned i, unsigned j);
 };
 
 

src/gallium/auxiliary/util/u_format_pack.py

@@ -324,23 +324,15 @@ def conversion_expr(src_channel, dst_channel, dst_native_type, value, clamp=True
     assert False
 
 
-def generate_format_unpack(format, dst_channel, dst_native_type, dst_suffix):
+def generate_unpack_kernel(format, dst_channel, dst_native_type):
-    '''Generate the function to unpack pixels from a particular format'''
 
-    name = format.short_name()
+    if not is_format_supported(format):
-
+        return
-    print 'static INLINE void'
-    print 'util_format_%s_unpack_%s(%s *dst, const uint8_t *src, unsigned length)' % (name, dst_suffix, dst_native_type)
-    print '{'
-
-    if is_format_supported(format):
     
     assert format.layout == PLAIN
 
     src_native_type = native_type(format)
 
-        print '   while(length--) {'
-    
     if format.is_bitmask():
         depth = format.block_size()
         print '      uint%u_t value = *(uint%u_t *)src;' % (depth, depth) 
@@ -434,32 +426,18 @@ def generate_format_unpack(format, dst_channel, dst_native_type, dst_suffix):
                     value = 'dst[0]'
             print '      dst[%u] = %s; /* %s */' % (i, value, 'rgba'[i])
     
-        print '      src += %u;' % (format.block_size() / 8,)
-        print '      dst += 4;'
-        print '   }'
 
-    print '}'
+def generate_pack_kernel(format, src_channel, src_native_type):
-    print
 
+    if not is_format_supported(format):
+        return
     
-def generate_format_pack(format, src_channel, src_native_type, src_suffix):
-    '''Generate the function to pack pixels to a particular format'''
-
-    name = format.short_name()
-
-    print 'static INLINE void'
-    print 'util_format_%s_pack_%s(uint8_t *dst, const %s *src, unsigned length)' % (name, src_suffix, src_native_type)
-    print '{'
-    
-    if is_format_supported(format):
     dst_native_type = native_type(format)
 
     assert format.layout == PLAIN
 
     inv_swizzle = format.inv_swizzles()
 
-        print '   while(length--) {'
-    
     if format.is_bitmask():
         depth = format.block_size()
         print '      uint%u_t value = 0;' % depth 
@@ -516,6 +494,43 @@ def generate_format_pack(format, src_channel, src_native_type, src_suffix):
         bswap_format(format)
         print '      memcpy(dst, &pixel, sizeof pixel);'
     
+
+def generate_format_unpack(format, dst_channel, dst_native_type, dst_suffix):
+    '''Generate the function to unpack pixels from a particular format'''
+
+    name = format.short_name()
+
+    print 'static INLINE void'
+    print 'util_format_%s_unpack_%s(%s *dst, const uint8_t *src, unsigned length)' % (name, dst_suffix, dst_native_type)
+    print '{'
+
+    if is_format_supported(format):
+        print '   while(length--) {'
+
+        generate_unpack_kernel(format, dst_channel, dst_native_type)
+    
+        print '      src += %u;' % (format.block_size() / 8,)
+        print '      dst += 4;'
+        print '   }'
+
+    print '}'
+    print
+    
+
+def generate_format_pack(format, src_channel, src_native_type, src_suffix):
+    '''Generate the function to pack pixels to a particular format'''
+
+    name = format.short_name()
+
+    print 'static INLINE void'
+    print 'util_format_%s_pack_%s(uint8_t *dst, const %s *src, unsigned length)' % (name, src_suffix, src_native_type)
+    print '{'
+    
+    if is_format_supported(format):
+        print '   while(length--) {'
+    
+        generate_pack_kernel(format, src_channel, src_native_type)
+            
         print '      src += 4;'
         print '      dst += %u;' % (format.block_size() / 8,)
         print '   }'
@@ -524,18 +539,20 @@ def generate_format_pack(format, src_channel, src_native_type, src_suffix):
     print
     
 
-def generate_unpack(formats, dst_channel, dst_native_type, dst_suffix):
+def generate_format_fetch(format, dst_channel, dst_native_type, dst_suffix):
-    '''Generate the dispatch function to unpack pixels from any format'''
+    '''Generate the function to unpack pixels from a particular format'''
 
-    for format in formats:
+    name = format.short_name()
-        generate_format_unpack(format, dst_channel, dst_native_type, dst_suffix)
 
+    print 'static INLINE void'
+    print 'util_format_%s_fetch_%s(%s *dst, const uint8_t *src, unsigned i, unsigned j)' % (name, dst_suffix, dst_native_type)
+    print '{'
 
-def generate_pack(formats, src_channel, src_native_type, src_suffix):
+    if is_format_supported(format):
-    '''Generate the dispatch function to pack pixels to any format'''
+        generate_unpack_kernel(format, dst_channel, dst_native_type)
 
-    for format in formats:
+    print '}'
-        generate_format_pack(format, src_channel, src_native_type, src_suffix)
+    print
 
 
 def generate(formats):
@@ -555,13 +572,16 @@ def generate(formats):
     native_type = 'float'
     suffix = 'float'
 
-    generate_unpack(formats, channel, native_type, suffix)
+    for format in formats:
-    generate_pack(formats, channel, native_type, suffix)
+        generate_format_unpack(format, channel, native_type, suffix)
+        generate_format_pack(format, channel, native_type, suffix)
+        generate_format_fetch(format, channel, native_type, suffix)
 
     channel = Channel(UNSIGNED, True, 8)
     native_type = 'uint8_t'
     suffix = '8unorm'
 
-    generate_unpack(formats, channel, native_type, suffix)
+    for format in formats:
-    generate_pack(formats, channel, native_type, suffix)
+        generate_format_unpack(format, channel, native_type, suffix)
+        generate_format_pack(format, channel, native_type, suffix)
 

src/gallium/auxiliary/util/u_format_table.py

@@ -106,6 +106,11 @@ util_format_none_unpack_float(float *dst, const uint8_t *src, unsigned length)
 static void
 util_format_none_pack_float(uint8_t *dst, const float *src, unsigned length)
 {
+}
+
+static void
+util_format_none_fetch_float(float *dst, const uint8_t *src, unsigned i, unsigned j)
+{
 }
     '''
     print 'const struct util_format_description'
@@ -125,7 +130,8 @@ util_format_none_pack_float(uint8_t *dst, const float *src, unsigned length)
     print "   &util_format_none_unpack_8unorm," 
     print "   &util_format_none_pack_8unorm," 
     print "   &util_format_none_unpack_float," 
-    print "   &util_format_none_pack_float" 
+    print "   &util_format_none_pack_float,"
+    print "   &util_format_none_fetch_float"
     print "};"
     print
     
@@ -172,7 +178,8 @@ util_format_none_pack_float(uint8_t *dst, const float *src, unsigned length)
         print "   &util_format_%s_unpack_8unorm," % format.short_name() 
         print "   &util_format_%s_pack_8unorm," % format.short_name() 
         print "   &util_format_%s_unpack_float," % format.short_name() 
-        print "   &util_format_%s_pack_float" % format.short_name() 
+        print "   &util_format_%s_pack_float," % format.short_name() 
+        print "   &util_format_%s_fetch_float" % format.short_name() 
         print "};"
         print