Bug 697345 Blend Color Space Support for Separation devices

This is a rather large commit that brings support for transparency
blend color spaces to the separation devices.  Previously the
transparency compositor always used CMYK for the blend color space
if the output device was a separation device.

With this commit:

If the blend space is RGB or Gray based, then we now ensure that the
alternate tint transform is not used when we encounter a separation or DeviceN color space.
(assuming we have not run out of spot color space at the target device).   Note that
if the any of the spot colors in a DeviceN color space are CMYK process colorants and the
blend space is Gray or RGB, the alternate tint transform IS used.

2) The pdf14 compositor now handles a mixture of additive and subtractive components.
I.e. RGB + spots or Gray + spots.

3) If the blend mode is non white preserving or not separable, then the spot colors
use the normal blend mode while the process colorants use the specified blend mode.

4) In the process there was a bit of code clean up. But much remains to be cleaned.

1 files changed, 26 insertions, 15 deletions

diff --git a/base/gxdcolor.c b/base/gxdcolor.c
index 4fdfe93bb..f6a7ece41 100644
--- a/base/gxdcolor.c
+++ b/base/gxdcolor.c
@@ -23,6 +23,7 @@
 #include "gxpcolor.h"
 #include "gxdevice.h"
 #include "gxdevcli.h"
+#include "gxclist.h"
 
 /* Define the standard device color types. */
 
@@ -417,7 +418,7 @@ static void
 gx_dc_devn_save_dc(const gx_device_color * pdevc, gx_device_color_saved * psdc)
 {
     psdc->type = pdevc->type;
-    memcpy(&(psdc->colors.devn.values[0]), &(pdevc->colors.devn.values[0]), 
+    memcpy(&(psdc->colors.devn.values[0]), &(pdevc->colors.devn.values[0]),
            GX_DEVICE_COLOR_MAX_COMPONENTS*sizeof(ushort));
 }
 
@@ -431,8 +432,8 @@ gx_dc_devn_load(gx_device_color * pdevc, const gs_gstate * ignore_pgs,
 /* Fill a rectangle with a devicen color. */
 static int
 gx_dc_devn_fill_rectangle(const gx_device_color * pdevc, int x, int y,
-                          int w, int h, gx_device * dev, 
-                          gs_logical_operation_t lop, 
+                          int w, int h, gx_device * dev,
+                          gs_logical_operation_t lop,
                           const gx_rop_source_t * source)
 {
     gs_fixed_rect rect;
@@ -445,8 +446,8 @@ gx_dc_devn_fill_rectangle(const gx_device_color * pdevc, int x, int y,
 }
 
 /* Fill a mask with a DeviceN color. */
-/* Note that there is no source in this case: the mask is the source. 
-   I would like to add a device proc that was fill_masked_hl for 
+/* Note that there is no source in this case: the mask is the source.
+   I would like to add a device proc that was fill_masked_hl for
    handling this instead of breaking this down to hl rect fills */
 int
 gx_dc_devn_fill_masked(const gx_device_color * pdevc, const byte * data,
@@ -538,8 +539,8 @@ gx_dc_devn_equal(const gx_device_color * pdevc1, const gx_device_color * pdevc2)
 
 /*
  * Utility to write a devn color into the clist.   We should only be here
- * if the device can handle these colors (e.g. a separation device like 
- * tiffsep).  TODO:  Reduce the size of this by removing leading zeros in 
+ * if the device can handle these colors (e.g. a separation device like
+ * tiffsep).  TODO:  Reduce the size of this by removing leading zeros in
  * the mask.
  *
  */
@@ -551,12 +552,22 @@ gx_devn_write_color(
     uint *              psize )
 {
     int                 num_bytes1, num_bytes_temp, num_bytes;
-    gx_color_index      mask, mask_temp;
-    int                 count;
-    uchar                 i, ncomps = dev->color_info.num_components;
+    gx_color_index      mask_temp;
+    int                 count = 0;
+    uchar               i;
+    gx_device_clist_writer* const cdev = &((gx_device_clist *)dev)->writer;
+    uchar ncomps = cdev->clist_color_info.num_components; /* Could be different than target if 1.4 device */
+    gx_color_index  mask = 0x1, comp_bits = 0;
+
+    /* First find the number of non zero values */
+    for (i = 0; i < ncomps; i++, mask <<= 1) {
+        if (pdevc->colors.devn.values[i] != 0) {
+            comp_bits |= mask;
+            count++;
+        }
+    }
+    mask = comp_bits;
 
-    /* Figure out the size needed.  First find the number of non zero values */
-    count = gx_dc_devn_get_nonzero_comps(pdevc, dev, &mask);
     num_bytes1 = sizeof(gx_color_index);
     num_bytes = num_bytes1 + count * 2;
     num_bytes_temp = num_bytes1;
@@ -688,7 +699,7 @@ gx_devn_read_color(
             values[i] = 0;
         }
         mask >>= 1;
-    } 
+    }
     return num_bytes;
 }
 
@@ -736,10 +747,10 @@ gx_dc_devn_read(
     return gx_devn_read_color(&(pdevc->colors.devn.values[0]), dev, pdata, size);
 }
 
-/* Remember these are 16 bit values.   Also here we return the number of 
+/* Remember these are 16 bit values.   Also here we return the number of
    nonzero entries so we can figure out the size for the clist more
    easily.   Hopefully that does not cause any confusion in overprint
-   situations where is where this operation is also used. */
+   situations where this operation is also used. */
 int
 gx_dc_devn_get_nonzero_comps(
     const gx_device_color * pdevc,