Added OpenCL support to color-to-alpha

2 files changed, 128 insertions, 0 deletions

diff --git a/opencl/color-to-alpha.cl b/opencl/color-to-alpha.cl
new file mode 100644
index 00000000..9ca08949
--- /dev/null
+++ b/opencl/color-to-alpha.cl
@@ -0,0 +1,63 @@
+__kernel void cl_color_to_alpha(__global const float4 *in,
+                                __global       float4 *out,
+                                float4                color)
+{
+  int gid = get_global_id(0);
+  float4 in_v = in[gid];
+  float4 out_v = in_v;
+  float4 alpha;
+
+  alpha.w = in_v.w;
+
+  /*First component*/
+  if ( color.x < 0.00001f )
+    alpha.x = in_v.x;
+  else if ( in_v.x > color.x + 0.00001f )
+    alpha.x = (in_v.x - color.x) / (1.0f - color.x);
+  else if ( in_v.x < color.x - 0.00001f )
+    alpha.x = (color.x - in_v.x) / color.x;
+  else
+    alpha.x = 0.0f;
+  /*Second component*/
+  if ( color.y < 0.00001f )
+    alpha.y = in_v.y;
+  else if ( in_v.y > color.y + 0.00001f )
+    alpha.y = (in_v.y - color.y) / (1.0f - color.y);
+  else if ( in_v.y < color.y - 0.00001f )
+    alpha.y = (color.y - in_v.y) / color.y;
+  else
+    alpha.y = 0.0f;
+  /*Third component*/
+  if ( color.z < 0.00001f )
+    alpha.z = in_v.z;
+  else if ( in_v.z > color.z + 0.00001f )
+    alpha.z = (in_v.z - color.z) / (1.0f - color.z);
+  else if ( in_v.z < color.z - 0.00001f )
+    alpha.z = (color.z - in_v.z) / color.z;
+  else
+    alpha.z = 0.0f;
+
+  if (alpha.x > alpha.y)
+    {
+      if (alpha.x > alpha.z)
+        out_v.w = alpha.x;
+      else
+        out_v.w = alpha.z;
+    }
+  else if (alpha.y > alpha.z)
+    {
+      out_v.w = alpha.y;
+    }
+  else
+    {
+      out_v.w = alpha.z;
+    }
+
+  if (out_v.w >= 0.00001f)
+    {
+      out_v.xyz = (out_v.xyz - color.xyz) / out_v.www + color.xyz;
+      out_v.w *= alpha.w;
+    }
+
+    out[gid] = out_v;
+}
diff --git a/opencl/color-to-alpha.cl.h b/opencl/color-to-alpha.cl.h
new file mode 100644
index 00000000..409e0bc6
--- /dev/null
+++ b/opencl/color-to-alpha.cl.h
@@ -0,0 +1,65 @@
+static const char* color_to_alpha_cl_source =
+"__kernel void cl_color_to_alpha(__global const float4 *in,                    \n"
+"                                __global       float4 *out,                   \n"
+"                                float4                color)                  \n"
+"{                                                                             \n"
+"  int gid = get_global_id(0);                                                 \n"
+"  float4 in_v = in[gid];                                                      \n"
+"  float4 out_v = in_v;                                                        \n"
+"  float4 alpha;                                                               \n"
+"                                                                              \n"
+"  alpha.w = in_v.w;                                                           \n"
+"                                                                              \n"
+"  /*First component*/                                                         \n"
+"  if ( color.x < 0.00001f )                                                   \n"
+"    alpha.x = in_v.x;                                                         \n"
+"  else if ( in_v.x > color.x + 0.00001f )                                     \n"
+"    alpha.x = (in_v.x - color.x) / (1.0f - color.x);                          \n"
+"  else if ( in_v.x < color.x - 0.00001f )                                     \n"
+"    alpha.x = (color.x - in_v.x) / color.x;                                   \n"
+"  else                                                                        \n"
+"    alpha.x = 0.0f;                                                           \n"
+"  /*Second component*/                                                        \n"
+"  if ( color.y < 0.00001f )                                                   \n"
+"    alpha.y = in_v.y;                                                         \n"
+"  else if ( in_v.y > color.y + 0.00001f )                                     \n"
+"    alpha.y = (in_v.y - color.y) / (1.0f - color.y);                          \n"
+"  else if ( in_v.y < color.y - 0.00001f )                                     \n"
+"    alpha.y = (color.y - in_v.y) / color.y;                                   \n"
+"  else                                                                        \n"
+"    alpha.y = 0.0f;                                                           \n"
+"  /*Third component*/                                                         \n"
+"  if ( color.z < 0.00001f )                                                   \n"
+"    alpha.z = in_v.z;                                                         \n"
+"  else if ( in_v.z > color.z + 0.00001f )                                     \n"
+"    alpha.z = (in_v.z - color.z) / (1.0f - color.z);                          \n"
+"  else if ( in_v.z < color.z - 0.00001f )                                     \n"
+"    alpha.z = (color.z - in_v.z) / color.z;                                   \n"
+"  else                                                                        \n"
+"    alpha.z = 0.0f;                                                           \n"
+"                                                                              \n"
+"  if (alpha.x > alpha.y)                                                      \n"
+"    {                                                                         \n"
+"      if (alpha.x > alpha.z)                                                  \n"
+"        out_v.w = alpha.x;                                                    \n"
+"      else                                                                    \n"
+"        out_v.w = alpha.z;                                                    \n"
+"    }                                                                         \n"
+"  else if (alpha.y > alpha.z)                                                 \n"
+"    {                                                                         \n"
+"      out_v.w = alpha.y;                                                      \n"
+"    }                                                                         \n"
+"  else                                                                        \n"
+"    {                                                                         \n"
+"      out_v.w = alpha.z;                                                      \n"
+"    }                                                                         \n"
+"                                                                              \n"
+"  if (out_v.w >= 0.00001f)                                                    \n"
+"    {                                                                         \n"
+"      out_v.xyz = (out_v.xyz - color.xyz) / out_v.www + color.xyz;            \n"
+"      out_v.w *= alpha.w;                                                     \n"
+"    }                                                                         \n"
+"                                                                              \n"
+"    out[gid] = out_v;                                                         \n"
+"}                                                                             \n"
+;