Compositor: Full frame matte nodes

Adds full frame implementation to Channel Key, Chroma Key, Color Key,
Color Spill, Cryptomatte, Difference Key, Distance Key, Keying,
Keying Screen and Luminance Key nodes. The other nodes
in "Matte" sub-menu are submitted separately.

No functional changes.

Part of T88150.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D12220

1 files changed, 34 insertions, 0 deletions

diff --git a/source/blender/compositor/operations/COM_ChannelMatteOperation.cc b/source/blender/compositor/operations/COM_ChannelMatteOperation.cc
index ec4331dc231..65742d0cfcc 100644
--- a/source/blender/compositor/operations/COM_ChannelMatteOperation.cc
+++ b/source/blender/compositor/operations/COM_ChannelMatteOperation.cc
@@ -27,6 +27,7 @@ ChannelMatteOperation::ChannelMatteOperation()
   addOutputSocket(DataType::Value);
 
   this->m_inputImageProgram = nullptr;
+  flags.can_be_constant = true;
 }
 
 void ChannelMatteOperation::initExecution()
@@ -121,4 +122,37 @@ void ChannelMatteOperation::executePixelSampled(float output[4],
   output[0] = MIN2(alpha, inColor[3]);
 }
 
+void ChannelMatteOperation::update_memory_buffer_partial(MemoryBuffer *output,
+                                                         const rcti &area,
+                                                         Span<MemoryBuffer *> inputs)
+{
+  for (BuffersIterator<float> it = output->iterate_with(inputs, area); !it.is_end(); ++it) {
+    const float *color = it.in(0);
+
+    /* Matte operation. */
+    float alpha = color[this->m_ids[0]] - MAX2(color[this->m_ids[1]], color[this->m_ids[2]]);
+
+    /* Flip because 0.0 is transparent, not 1.0. */
+    alpha = 1.0f - alpha;
+
+    /* Test range. */
+    if (alpha > m_limit_max) {
+      alpha = color[3]; /* Whatever it was prior. */
+    }
+    else if (alpha < m_limit_min) {
+      alpha = 0.0f;
+    }
+    else { /* Blend. */
+      alpha = (alpha - m_limit_min) / m_limit_range;
+    }
+
+    /* Store matte(alpha) value in [0] to go with
+     * COM_SetAlphaMultiplyOperation and the Value output.
+     */
+
+    /* Don't make something that was more transparent less transparent. */
+    *it.out = MIN2(alpha, color[3]);
+  }
+}
+
 }  // namespace blender::compositor