[Bf-blender-cvs] [3b23b5c638f] master: Images: don't (un)premultipy non-color data
Brecht Van Lommel
noreply at git.blender.org
Sun May 19 14:37:42 CEST 2019
Commit: 3b23b5c638feae0ad6319440771b83a64a1f9ebe
Author: Brecht Van Lommel
Date: Sun May 19 02:56:12 2019 +0200
Branches: master
https://developer.blender.org/rB3b23b5c638feae0ad6319440771b83a64a1f9ebe
Images: don't (un)premultipy non-color data
The previous behavior here was wrong for some specific combinations of
settings, non-color RGB channels should never be affected by the alpha
channel.
===================================================================
M intern/cycles/render/colorspace.cpp
M intern/cycles/render/colorspace.h
M intern/cycles/render/image.cpp
M intern/cycles/render/nodes.cpp
M source/blender/imbuf/intern/readimage.c
M source/blender/nodes/shader/nodes/node_shader_tex_image.c
===================================================================
diff --git a/intern/cycles/render/colorspace.cpp b/intern/cycles/render/colorspace.cpp
index 7b57478ff51..f4c217bc9fb 100644
--- a/intern/cycles/render/colorspace.cpp
+++ b/intern/cycles/render/colorspace.cpp
@@ -82,6 +82,31 @@ ColorSpaceProcessor *ColorSpaceManager::get_processor(ustring colorspace)
#endif
}
+bool ColorSpaceManager::colorspace_is_data(ustring colorspace)
+{
+ if (colorspace == u_colorspace_auto || colorspace == u_colorspace_raw ||
+ colorspace == u_colorspace_srgb) {
+ return false;
+ }
+
+#ifdef WITH_OCIO
+ OCIO::ConstConfigRcPtr config = OCIO::GetCurrentConfig();
+ if (!config) {
+ return false;
+ }
+
+ try {
+ OCIO::ConstColorSpaceRcPtr space = config->getColorSpace(colorspace.c_str());
+ return space && space->isData();
+ }
+ catch (OCIO::Exception &exception) {
+ return false;
+ }
+#else
+ return false;
+#endif
+}
+
ustring ColorSpaceManager::detect_known_colorspace(ustring colorspace,
const char *file_format,
bool is_float)
diff --git a/intern/cycles/render/colorspace.h b/intern/cycles/render/colorspace.h
index e7c7f943c2d..9fea2d6efc6 100644
--- a/intern/cycles/render/colorspace.h
+++ b/intern/cycles/render/colorspace.h
@@ -37,6 +37,9 @@ class ColorSpaceManager {
const char *file_format,
bool is_float);
+ /* Test if colorspace is for non-color data. */
+ static bool colorspace_is_data(ustring colorspace);
+
/* Convert pixels in the specified colorspace to scene linear color for
* rendering. Must be a colorspace returned from detect_known_colorspace. */
template<typename T>
diff --git a/intern/cycles/render/image.cpp b/intern/cycles/render/image.cpp
index 431e9230cb4..6301b416724 100644
--- a/intern/cycles/render/image.cpp
+++ b/intern/cycles/render/image.cpp
@@ -513,8 +513,14 @@ bool ImageManager::file_load_image_generic(Image *img, unique_ptr<ImageInput> *i
ImageSpec spec = ImageSpec();
ImageSpec config = ImageSpec();
- if (img->use_alpha == false)
+ /* For typical RGBA images we let OIIO convert to associated alpha,
+ * but some types we want to leave the RGB channels untouched. */
+ const bool associate_alpha = !(ColorSpaceManager::colorspace_is_data(img->colorspace) ||
+ img->use_alpha == false);
+
+ if (!associate_alpha) {
config.attribute("oiio:UnassociatedAlpha", 1);
+ }
if (!(*in)->open(img->filename, spec, config)) {
return false;
diff --git a/intern/cycles/render/nodes.cpp b/intern/cycles/render/nodes.cpp
index 27e6309ab2d..3905189c8b0 100644
--- a/intern/cycles/render/nodes.cpp
+++ b/intern/cycles/render/nodes.cpp
@@ -316,7 +316,12 @@ void ImageTextureNode::compile(SVMCompiler &compiler)
flags |= NODE_IMAGE_COMPRESS_AS_SRGB;
}
if (!alpha_out->links.empty()) {
- flags |= NODE_IMAGE_ALPHA_UNASSOCIATE;
+ const bool unassociate_alpha = !(ColorSpaceManager::colorspace_is_data(colorspace) ||
+ use_alpha == false);
+
+ if (unassociate_alpha) {
+ flags |= NODE_IMAGE_ALPHA_UNASSOCIATE;
+ }
}
if (projection != NODE_IMAGE_PROJ_BOX) {
@@ -389,11 +394,14 @@ void ImageTextureNode::compile(OSLCompiler &compiler)
compiler.parameter_texture("filename", slot);
}
+ const bool unassociate_alpha = !(ColorSpaceManager::colorspace_is_data(colorspace) ||
+ use_alpha == false);
+
compiler.parameter(this, "projection");
compiler.parameter(this, "projection_blend");
compiler.parameter("convert_from_srgb", compress_as_srgb);
compiler.parameter("ignore_alpha", !use_alpha);
- compiler.parameter("unassociate_alpha", !alpha_out->links.empty());
+ compiler.parameter("unassociate_alpha", !alpha_out->links.empty() && unassociate_alpha);
compiler.parameter("is_float", is_float);
compiler.parameter(this, "interpolation");
compiler.parameter(this, "extension");
diff --git a/source/blender/imbuf/intern/readimage.c b/source/blender/imbuf/intern/readimage.c
index e1df5c63093..9297227bc87 100644
--- a/source/blender/imbuf/intern/readimage.c
+++ b/source/blender/imbuf/intern/readimage.c
@@ -49,8 +49,6 @@ static void imb_handle_alpha(ImBuf *ibuf,
char colorspace[IM_MAX_SPACE],
char effective_colorspace[IM_MAX_SPACE])
{
- int alpha_flags;
-
if (colorspace) {
if (ibuf->rect != NULL && ibuf->rect_float == NULL) {
/* byte buffer is never internally converted to some standard space,
@@ -62,6 +60,9 @@ static void imb_handle_alpha(ImBuf *ibuf,
BLI_strncpy(colorspace, effective_colorspace, IM_MAX_SPACE);
}
+ bool is_data = (colorspace && IMB_colormanagement_space_name_is_data(colorspace));
+ int alpha_flags;
+
if (flags & IB_alphamode_detect) {
alpha_flags = ibuf->flags & IB_alphamode_premul;
}
@@ -69,7 +70,10 @@ static void imb_handle_alpha(ImBuf *ibuf,
alpha_flags = flags & IB_alphamode_premul;
}
- if (flags & IB_ignore_alpha) {
+ if (is_data) {
+ /* Don't touch alpha. */
+ }
+ else if (flags & IB_ignore_alpha) {
IMB_rectfill_alpha(ibuf, 1.0f);
}
else {
diff --git a/source/blender/nodes/shader/nodes/node_shader_tex_image.c b/source/blender/nodes/shader/nodes/node_shader_tex_image.c
index a9183cd10ef..8086bb2e15d 100644
--- a/source/blender/nodes/shader/nodes/node_shader_tex_image.c
+++ b/source/blender/nodes/shader/nodes/node_shader_tex_image.c
@@ -180,6 +180,9 @@ static int node_shader_gpu_tex_image(GPUMaterial *mat,
}
if (out[0].hasoutput) {
+ /* When the alpha socket is used, unpremultiply alpha. This makes it so
+ * that if we blend the color with a transparent shader using alpha as
+ * a factor, we don't multiply alpha into the color twice. */
if (out[1].hasoutput &&
!IMB_colormanagement_space_name_is_data(ima->colorspace_settings.name)) {
GPU_link(mat, "tex_color_alpha_unpremultiply", out[0].link, &out[0].link);
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