mesa: Add a helper function _mesa_need_luminance_to_rgb_conversion()

Cc: <[email protected]>
Signed-off-by: Anuj Phogat <[email protected]>
Reviewed-by: Iago Toral Quiroga <[email protected]>

2 files changed, 22 insertions, 0 deletions

diff --git a/src/mesa/main/readpix.c b/src/mesa/main/readpix.c
index 25a09873fe0..ac46f7e47de 100644
--- a/src/mesa/main/readpix.c
+++ b/src/mesa/main/readpix.c
@@ -60,6 +60,24 @@ _mesa_need_rgb_to_luminance_conversion(mesa_format texFormat, GLenum format)
            format == GL_LUMINANCE_ALPHA_INTEGER_EXT);
 }
 
+/**
+ * Return true if the conversion L,I to RGB conversion is needed.
+ */
+GLboolean
+_mesa_need_luminance_to_rgb_conversion(GLenum srcBaseFormat,
+                                       GLenum dstBaseFormat)
+{
+   return (srcBaseFormat == GL_LUMINANCE ||
+           srcBaseFormat == GL_LUMINANCE_ALPHA ||
+           srcBaseFormat == GL_INTENSITY) &&
+          (dstBaseFormat == GL_GREEN ||
+           dstBaseFormat == GL_BLUE ||
+           dstBaseFormat == GL_RG ||
+           dstBaseFormat == GL_RGB ||
+           dstBaseFormat == GL_BGR ||
+           dstBaseFormat == GL_RGBA ||
+           dstBaseFormat == GL_BGRA);
+}
 
 /**
  * Return transfer op flags for this ReadPixels operation.
diff --git a/src/mesa/main/readpix.h b/src/mesa/main/readpix.h
index f8940361fb4..41116e430ec 100644
--- a/src/mesa/main/readpix.h
+++ b/src/mesa/main/readpix.h
@@ -40,6 +40,10 @@ _mesa_readpixels_needs_slow_path(const struct gl_context *ctx, GLenum format,
 extern GLboolean
 _mesa_need_rgb_to_luminance_conversion(mesa_format texFormat, GLenum format);
 
+extern GLboolean
+_mesa_need_luminance_to_rgb_conversion(GLenum srcBaseFormat,
+                                       GLenum dstBaseFormat);
+
 extern GLbitfield
 _mesa_get_readpixels_transfer_ops(const struct gl_context *ctx,
                                   mesa_format texFormat,