Packed and generated images support for Cycles

This commit adds support of packed and generated images
for Cycles when using SVM backend. Movies are still not
supported. This changes also doesn't touch OSL which is
much less trivial to adopt for any images which are not
saved to disk.

Implementation details:

- When adding images to Image Manager is now possible
  to mark image as builtin. Builtin images will bypass
  OIIO loader and will use special loading callbacks.

- Callbacks are set by Blender Session and they're
  using C++ RNA interface to obtain needed data (pixels,
  dimensions, is_float flag).

- Image Manager assumes file path is used as reference
  to a builtin images, but in fact currently image
  datablock name is used for reference. This makes it
  easy to find an image in BlendData database.

- Added some extra properties to Image RNA:
  * channels, which denotes actual number of channels
    in ImBuf. This is needed to treat image's pixels
    correct (before it wasn't possible because API
    used internal number of channels for pixels which
    is in fact doesn't correlate with image depth)
  * is_float, which is truth if image is stored in
    float buffer of ImBuf.

- Implemented string lookup for C++ RNA collections
  for cases there's no manual lookup function.

OSL is not supported because it used own image loading
and filtering routines and there's seems to be no API
to feed pre-loaded pixels directly to the library.

Think we'll either need to add some API to support
such kind of feeding or consider OSL does not have
support of packed images at all.

Movies are not supported at this moment because of lack
of RNA API to load specified frame. It's not difficult
to solve, just need to consider what to best here:
* Either write some general python interface for ImBuf
  and use it via C++ API, or
* Write a PY API function which will return pixels for
  given frame, or
* Use bad-level BKE_* call

Anyway, small steps, further improvements later.

Reviewed by Brecht, thanks!

7 files changed, 220 insertions, 62 deletions

diff --git a/intern/cycles/blender/blender_session.cpp b/intern/cycles/blender/blender_session.cpp
index d0c7c06cbb3..60dfe37c9f8 100644
--- a/intern/cycles/blender/blender_session.cpp
+++ b/intern/cycles/blender/blender_session.cpp
@@ -109,6 +109,11 @@ void BlenderSession::create_session()
 	session->reset(buffer_params, session_params.samples);
 
 	b_engine.use_highlight_tiles(session_params.progressive_refine == false);
+
+	/* setup callbacks for builtin image support */
+	scene->image_manager->builtin_image_info_cb = function_bind(&BlenderSession::builtin_image_info, this, _1, _2, _3, _4, _5);
+	scene->image_manager->builtin_image_pixels_cb = function_bind(&BlenderSession::builtin_image_pixels, this, _1, _2);
+	scene->image_manager->builtin_image_float_pixels_cb = function_bind(&BlenderSession::builtin_image_float_pixels, this, _1, _2);
 }
 
 void BlenderSession::reset_session(BL::BlendData b_data_, BL::Scene b_scene_)
@@ -607,5 +612,69 @@ void BlenderSession::test_cancel()
 			session->progress.set_cancel("Cancelled");
 }
 
+void BlenderSession::builtin_image_info(const string &name, bool &is_float, int &width, int &height, int &channels)
+{
+	BL::Image b_image = b_data.images[name];
+
+	if(b_image) {
+		is_float = b_image.is_float();
+		width = b_image.size()[0];
+		height = b_image.size()[1];
+		channels = b_image.channels();
+	}
+	else {
+		is_float = false;
+		width = 0;
+		height = 0;
+		channels = 0;
+	}
+}
+
+bool BlenderSession::builtin_image_pixels(const string &name, unsigned char *pixels)
+{
+	BL::Image b_image = b_data.images[name];
+
+	if(b_image) {
+		int width = b_image.size()[0];
+		int height = b_image.size()[1];
+		int channels = b_image.channels();
+
+		BL::DynamicArray<float> pixels_array = b_image.pixels();
+		float *float_pixels = pixels_array.data;
+
+		/* a bit of shame, but Py API currently only returns float array,
+		 * which need to be converted back to char buffer
+		 */
+		unsigned char *cp = pixels;
+		float *fp = float_pixels;
+		for(int i = 0; i < channels * width * height; i++, cp++, fp++) {
+			*cp = *fp * 255;
+		}
+
+		return true;
+	}
+
+	return false;
+}
+
+bool BlenderSession::builtin_image_float_pixels(const string &name, float *pixels)
+{
+	BL::Image b_image = b_data.images[name];
+
+	if(b_image) {
+		int width = b_image.size()[0];
+		int height = b_image.size()[1];
+		int channels = b_image.channels();
+
+		BL::DynamicArray<float> pixels_array = b_image.pixels();
+
+		memcpy(pixels, pixels_array.data, width * height * channels * sizeof(float));
+
+		return true;
+	}
+
+	return false;
+}
+
 CCL_NAMESPACE_END
 
diff --git a/intern/cycles/blender/blender_session.h b/intern/cycles/blender/blender_session.h
index 7f3973ae873..dfa487bd244 100644
--- a/intern/cycles/blender/blender_session.h
+++ b/intern/cycles/blender/blender_session.h
@@ -93,6 +93,10 @@ public:
 protected:
 	void do_write_update_render_result(BL::RenderResult b_rr, BL::RenderLayer b_rlay, RenderTile& rtile, bool do_update_only);
 	void do_write_update_render_tile(RenderTile& rtile, bool do_update_only);
+
+	void builtin_image_info(const string &name, bool &is_float, int &width, int &height, int &channels);
+	bool builtin_image_pixels(const string &name, unsigned char *pixels);
+	bool builtin_image_float_pixels(const string &name, float *pixels);
 };
 
 CCL_NAMESPACE_END
diff --git a/intern/cycles/blender/blender_shader.cpp b/intern/cycles/blender/blender_shader.cpp
index ddbd7f935e4..3bb02bbfe74 100644
--- a/intern/cycles/blender/blender_shader.cpp
+++ b/intern/cycles/blender/blender_shader.cpp
@@ -511,9 +511,24 @@ static ShaderNode *add_node(Scene *scene, BL::BlendData b_data, BL::Scene b_scen
 			BL::ShaderNodeTexImage b_image_node(b_node);
 			BL::Image b_image(b_image_node.image());
 			ImageTextureNode *image = new ImageTextureNode();
-			/* todo: handle generated/builtin images */
+			/* todo: handle movie images */
 			if(b_image && b_image.source() != BL::Image::source_MOVIE) {
-				image->filename = image_user_file_path(b_image_node.image_user(), b_image, b_scene.frame_current());
+				/* builtin images will use callback-based reading because
+				 * they could only be loaded correct from blender side
+				 */
+				bool is_builtin = b_image.packed_file() ||
+				                  b_image.source() == BL::Image::source_GENERATED;
+
+				if(is_builtin) {
+					/* for builtin images we're using image datablock name to find an image to read pixels from later */
+					image->filename = b_image.name();
+					image->is_builtin = true;
+				}
+				else {
+					image->filename = image_user_file_path(b_image_node.image_user(), b_image, b_scene.frame_current());
+					image->is_builtin = false;
+				}
+
 				image->animated = b_image_node.image_user().use_auto_refresh();
 			}
 			image->color_space = ImageTextureNode::color_space_enum[(int)b_image_node.color_space()];
@@ -528,8 +543,17 @@ static ShaderNode *add_node(Scene *scene, BL::BlendData b_data, BL::Scene b_scen
 			BL::Image b_image(b_env_node.image());
 			EnvironmentTextureNode *env = new EnvironmentTextureNode();
 			if(b_image && b_image.source() != BL::Image::source_MOVIE) {
-				env->filename = image_user_file_path(b_env_node.image_user(), b_image, b_scene.frame_current());
-				env->animated = b_env_node.image_user().use_auto_refresh();
+				bool is_builtin = b_image.packed_file() ||
+				                  b_image.source() == BL::Image::source_GENERATED;
+
+				if(is_builtin) {
+					env->filename = b_image.name();
+					env->is_builtin = true;
+				}
+				else {
+					env->filename = image_user_file_path(b_env_node.image_user(), b_image, b_scene.frame_current());
+					env->animated = b_env_node.image_user().use_auto_refresh();
+				}
 			}
 			env->color_space = EnvironmentTextureNode::color_space_enum[(int)b_env_node.color_space()];
 			env->projection = EnvironmentTextureNode::projection_enum[(int)b_env_node.projection()];
diff --git a/intern/cycles/render/image.cpp b/intern/cycles/render/image.cpp
index 230a12f9ff2..e6f8ab4a5d9 100644
--- a/intern/cycles/render/image.cpp
+++ b/intern/cycles/render/image.cpp
@@ -85,11 +85,21 @@ bool ImageManager::set_animation_frame_update(int frame)
 	return false;
 }
 
-bool ImageManager::is_float_image(const string& filename)
+bool ImageManager::is_float_image(const string& filename, bool is_builtin)
 {
-	ImageInput *in = ImageInput::create(filename);
 	bool is_float = false;
 
+	if(is_builtin) {
+		if(builtin_image_info_cb) {
+			int width, height, channels;
+			builtin_image_info_cb(filename, is_float, width, height, channels);
+		}
+
+		return is_float;
+	}
+
+	ImageInput *in = ImageInput::create(filename);
+
 	if(in) {
 		ImageSpec spec;
 
@@ -113,13 +123,13 @@ bool ImageManager::is_float_image(const string& filename)
 	return is_float;
 }
 
-int ImageManager::add_image(const string& filename, bool animated, bool& is_float)
+int ImageManager::add_image(const string& filename, bool is_builtin, bool animated, bool& is_float)
 {
 	Image *img;
 	size_t slot;
 
 	/* load image info and find out if we need a float texture */
-	is_float = (pack_images)? false: is_float_image(filename);
+	is_float = (pack_images)? false: is_float_image(filename, is_builtin);
 
 	if(is_float) {
 		/* find existing image */
@@ -150,6 +160,7 @@ int ImageManager::add_image(const string& filename, bool animated, bool& is_floa
 		/* add new image */
 		img = new Image();
 		img->filename = filename;
+		img->is_builtin = is_builtin;
 		img->need_load = true;
 		img->animated = animated;
 		img->users = 1;
@@ -184,6 +195,7 @@ int ImageManager::add_image(const string& filename, bool animated, bool& is_floa
 		/* add new image */
 		img = new Image();
 		img->filename = filename;
+		img->is_builtin = is_builtin;
 		img->need_load = true;
 		img->animated = animated;
 		img->users = 1;
@@ -197,12 +209,12 @@ int ImageManager::add_image(const string& filename, bool animated, bool& is_floa
 	return slot;
 }
 
-void ImageManager::remove_image(const string& filename)
+void ImageManager::remove_image(const string& filename, bool is_builtin)
 {
 	size_t slot;
 
 	for(slot = 0; slot < images.size(); slot++) {
-		if(images[slot] && images[slot]->filename == filename) {
+		if(images[slot] && images[slot]->filename == filename && images[slot]->is_builtin == is_builtin) {
 			/* decrement user count */
 			images[slot]->users--;
 			assert(images[slot]->users >= 0);
@@ -220,7 +232,7 @@ void ImageManager::remove_image(const string& filename)
 	if(slot == images.size()) {
 		/* see if it's in a float texture slot */
 		for(slot = 0; slot < float_images.size(); slot++) {
-			if(float_images[slot] && float_images[slot]->filename == filename) {
+			if(float_images[slot] && float_images[slot]->filename == filename && float_images[slot]->is_builtin == is_builtin) {
 				/* decrement user count */
 				float_images[slot]->users--;
 				assert(float_images[slot]->users >= 0);
@@ -242,27 +254,43 @@ bool ImageManager::file_load_image(Image *img, device_vector<uchar4>& tex_img)
 	if(img->filename == "")
 		return false;
 
-	/* load image from file through OIIO */
-	ImageInput *in = ImageInput::create(img->filename);
+	ImageInput *in = NULL;
+	int width, height, components;
 
-	if(!in)
-		return false;
+	if(!img->is_builtin) {
+		/* load image from file through OIIO */
+		in = ImageInput::create(img->filename);
 
-	ImageSpec spec;
+		if(!in)
+			return false;
 
-	if(!in->open(img->filename, spec)) {
-		delete in;
-		return false;
+		ImageSpec spec;
+
+		if(!in->open(img->filename, spec)) {
+			delete in;
+			return false;
+		}
+
+		width = spec.width;
+		height = spec.height;
+		components = spec.nchannels;
+	}
+	else {
+		/* load image using builtin images callbacks */
+		if(!builtin_image_info_cb || !builtin_image_pixels_cb)
+			return false;
+
+		bool is_float;
+		builtin_image_info_cb(img->filename, is_float, width, height, components);
 	}
 
 	/* we only handle certain number of components */
-	int width = spec.width;
-	int height = spec.height;
-	int components = spec.nchannels;
-
 	if(!(components == 1 || components == 3 || components == 4)) {
-		in->close();
-		delete in;
+		if(in) {
+			in->close();
+			delete in;
+		}
+
 		return false;
 	}
 
@@ -270,14 +298,19 @@ bool ImageManager::file_load_image(Image *img, device_vector<uchar4>& tex_img)
 	uchar *pixels = (uchar*)tex_img.resize(width, height);
 	int scanlinesize = width*components*sizeof(uchar);
 
-	in->read_image(TypeDesc::UINT8,
-		(uchar*)pixels + (height-1)*scanlinesize,
-		AutoStride,
-		-scanlinesize,
-		AutoStride);
+	if(in) {
+		in->read_image(TypeDesc::UINT8,
+			(uchar*)pixels + (height-1)*scanlinesize,
+			AutoStride,
+			-scanlinesize,
+			AutoStride);
 
-	in->close();
-	delete in;
+		in->close();
+		delete in;
+	}
+	else {
+		builtin_image_pixels_cb(img->filename, pixels);
+	}
 
 	if(components == 3) {
 		for(int i = width*height-1; i >= 0; i--) {
@@ -304,27 +337,42 @@ bool ImageManager::file_load_float_image(Image *img, device_vector<float4>& tex_
 	if(img->filename == "")
 		return false;
 
-	/* load image from file through OIIO */
-	ImageInput *in = ImageInput::create(img->filename);
+	ImageInput *in = NULL;
+	int width, height, components;
 
-	if(!in)
-		return false;
+	if(!img->is_builtin) {
+		/* load image from file through OIIO */
+		in = ImageInput::create(img->filename);
 
-	ImageSpec spec;
+		if(!in)
+			return false;
 
-	if(!in->open(img->filename, spec)) {
-		delete in;
-		return false;
+		ImageSpec spec;
+
+		if(!in->open(img->filename, spec)) {
+			delete in;
+			return false;
+		}
+
+		/* we only handle certain number of components */
+		width = spec.width;
+		height = spec.height;
+		components = spec.nchannels;
 	}
+	else {
+		/* load image using builtin images callbacks */
+		if(!builtin_image_info_cb || !builtin_image_float_pixels_cb)
+			return false;
 
-	/* we only handle certain number of components */
-	int width = spec.width;
-	int height = spec.height;
-	int components = spec.nchannels;
+		bool is_float;
+		builtin_image_info_cb(img->filename, is_float, width, height, components);
+	}
 
 	if(!(components == 1 || components == 3 || components == 4)) {
-		in->close();
-		delete in;
+		if(in) {
+			in->close();
+			delete in;
+		}
 		return false;
 	}
 
@@ -332,14 +380,19 @@ bool ImageManager::file_load_float_image(Image *img, device_vector<float4>& tex_
 	float *pixels = (float*)tex_img.resize(width, height);
 	int scanlinesize = width*components*sizeof(float);
 
-	in->read_image(TypeDesc::FLOAT,
-		(uchar*)pixels + (height-1)*scanlinesize,
-		AutoStride,
-		-scanlinesize,
-		AutoStride);
+	if(in) {
+		in->read_image(TypeDesc::FLOAT,
+			(uchar*)pixels + (height-1)*scanlinesize,
+			AutoStride,
+			-scanlinesize,
+			AutoStride);
 
-	in->close();
-	delete in;
+		in->close();
+		delete in;
+	}
+	else {
+		builtin_image_float_pixels_cb(img->filename, pixels);
+	}
 
 	if(components == 3) {
 		for(int i = width*height-1; i >= 0; i--) {
diff --git a/intern/cycles/render/image.h b/intern/cycles/render/image.h
index 4d177174971..e39ac14b60f 100644
--- a/intern/cycles/render/image.h
+++ b/intern/cycles/render/image.h
@@ -51,9 +51,9 @@ public:
 	ImageManager();
 	~ImageManager();
 
-	int add_image(const string& filename, bool animated, bool& is_float);
-	void remove_image(const string& filename);
-	bool is_float_image(const string& filename);
+	int add_image(const string& filename, bool is_builtin, bool animated, bool& is_float);
+	void remove_image(const string& filename, bool is_builtin);
+	bool is_float_image(const string& filename, bool is_builtin);
 
 	void device_update(Device *device, DeviceScene *dscene, Progress& progress);
 	void device_free(Device *device, DeviceScene *dscene);
@@ -65,6 +65,9 @@ public:
 
 	bool need_update;
 
+	boost::function<void(const string &filename, bool &is_float, int &width, int &height, int &channels)> builtin_image_info_cb;
+	boost::function<bool(const string &filename, unsigned char *pixels)> builtin_image_pixels_cb;
+	boost::function<bool(const string &filename, float *pixels)> builtin_image_float_pixels_cb;
 private:
 	int tex_num_images;
 	int tex_num_float_images;
@@ -74,6 +77,7 @@ private:
 
 	struct Image {
 		string filename;
+		bool is_builtin;
 
 		bool need_load;
 		bool animated;
diff --git a/intern/cycles/render/nodes.cpp b/intern/cycles/render/nodes.cpp
index 14ef3c68ad3..d1297c9dc94 100644
--- a/intern/cycles/render/nodes.cpp
+++ b/intern/cycles/render/nodes.cpp
@@ -142,6 +142,7 @@ ImageTextureNode::ImageTextureNode()
 	slot = -1;
 	is_float = -1;
 	filename = "";
+	is_builtin = false;
 	color_space = ustring("Color");
 	projection = ustring("Flat");;
 	projection_blend = 0.0f;
@@ -155,7 +156,7 @@ ImageTextureNode::ImageTextureNode()
 ImageTextureNode::~ImageTextureNode()
 {
 	if(image_manager)
-		image_manager->remove_image(filename);
+		image_manager->remove_image(filename, is_builtin);
 }
 
 ShaderNode *ImageTextureNode::clone() const
@@ -176,7 +177,7 @@ void ImageTextureNode::compile(SVMCompiler& compiler)
 	image_manager = compiler.image_manager;
 	if(is_float == -1) {
 		bool is_float_bool;
-		slot = image_manager->add_image(filename, animated, is_float_bool);
+		slot = image_manager->add_image(filename, is_builtin, animated, is_float_bool);
 		is_float = (int)is_float_bool;
 	}
 
@@ -237,7 +238,7 @@ void ImageTextureNode::compile(OSLCompiler& compiler)
 	tex_mapping.compile(compiler);
 
 	if(is_float == -1)
-		is_float = (int)image_manager->is_float_image(filename);
+		is_float = (int)image_manager->is_float_image(filename, false);
 
 	compiler.parameter("filename", filename.c_str());
 	if(is_float || color_space != "Color")
@@ -271,6 +272,7 @@ EnvironmentTextureNode::EnvironmentTextureNode()
 	slot = -1;
 	is_float = -1;
 	filename = "";
+	is_builtin = false;
 	color_space = ustring("Color");
 	projection = ustring("Equirectangular");
 	animated = false;
@@ -283,7 +285,7 @@ EnvironmentTextureNode::EnvironmentTextureNode()
 EnvironmentTextureNode::~EnvironmentTextureNode()
 {
 	if(image_manager)
-		image_manager->remove_image(filename);
+		image_manager->remove_image(filename, is_builtin);
 }
 
 ShaderNode *EnvironmentTextureNode::clone() const
@@ -304,7 +306,7 @@ void EnvironmentTextureNode::compile(SVMCompiler& compiler)
 	image_manager = compiler.image_manager;
 	if(slot == -1) {
 		bool is_float_bool;
-		slot = image_manager->add_image(filename, animated, is_float_bool);
+		slot = image_manager->add_image(filename, is_builtin, animated, is_float_bool);
 		is_float = (int)is_float_bool;
 	}
 
@@ -354,7 +356,7 @@ void EnvironmentTextureNode::compile(OSLCompiler& compiler)
 	tex_mapping.compile(compiler);
 
 	if(is_float == -1)
-		is_float = (int)image_manager->is_float_image(filename);
+		is_float = (int)image_manager->is_float_image(filename, false);
 
 	compiler.parameter("filename", filename.c_str());
 	compiler.parameter("projection", projection);
diff --git a/intern/cycles/render/nodes.h b/intern/cycles/render/nodes.h
index 564ceee5a5b..8b2d6a0e5c8 100644
--- a/intern/cycles/render/nodes.h
+++ b/intern/cycles/render/nodes.h
@@ -70,6 +70,7 @@ public:
 	int slot;
 	int is_float;
 	string filename;
+	bool is_builtin;
 	ustring color_space;
 	ustring projection;
 	float projection_blend;
@@ -89,6 +90,7 @@ public:
 	int slot;
 	int is_float;
 	string filename;
+	bool is_builtin;
 	ustring color_space;
 	ustring projection;
 	bool animated;