Cycles: Add support for single channel float textures on CPU.

Until now, single channel textures were packed into a float4, wasting 3 floats per pixel. Memory usage of such textures is now reduced by 3/4.
Voxel Attributes such as density, flame and heat benefit from this, but also Bumpmaps with one channel.
This commit also includes some cleanup and code deduplication for image loading.

Example Smoke render from Cosmos Laundromat: http://www.pasteall.org/pic/show.php?id=102972
Memory here went down from ~600MB to ~300MB.

Reviewers: #cycles, brecht

Differential Revision: https://developer.blender.org/D1981

4 files changed, 179 insertions, 84 deletions

diff --git a/intern/cycles/render/image.cpp b/intern/cycles/render/image.cpp
index 10a5ca42fc0..102c6107fb7 100644
--- a/intern/cycles/render/image.cpp
+++ b/intern/cycles/render/image.cpp
@@ -19,7 +19,6 @@
 #include "scene.h"
 
 #include "util_foreach.h"
-#include "util_image.h"
 #include "util_path.h"
 #include "util_progress.h"
 #include "util_texture.h"
@@ -43,31 +42,41 @@ ImageManager::ImageManager(const DeviceInfo& info)
 	if(info.type == DEVICE_CPU) {
 		tex_num_images[IMAGE_DATA_TYPE_BYTE4] = TEX_NUM_BYTE4_IMAGES_CPU;
 		tex_num_images[IMAGE_DATA_TYPE_FLOAT4] = TEX_NUM_FLOAT4_IMAGES_CPU;
+		tex_num_images[IMAGE_DATA_TYPE_FLOAT] = TEX_NUM_FLOAT_IMAGES_CPU;
 		tex_image_byte4_start = TEX_IMAGE_BYTE4_START_CPU;
+		tex_image_float_start = TEX_IMAGE_FLOAT_START_CPU;
 	}
 	/* CUDA (Fermi) */
 	else if((info.type == DEVICE_CUDA || info.type == DEVICE_MULTI) && !info.extended_images) {
 		tex_num_images[IMAGE_DATA_TYPE_BYTE4] = TEX_NUM_BYTE4_IMAGES_CUDA;
 		tex_num_images[IMAGE_DATA_TYPE_FLOAT4] = TEX_NUM_FLOAT4_IMAGES_CUDA;
+		tex_num_images[IMAGE_DATA_TYPE_FLOAT] = TEX_NUM_FLOAT_IMAGES_CUDA;
 		tex_image_byte4_start = TEX_IMAGE_BYTE4_START_CUDA;
+		tex_image_float_start = TEX_IMAGE_FLOAT_START_CUDA;
 	}
 	/* CUDA (Kepler and above) */
 	else if((info.type == DEVICE_CUDA || info.type == DEVICE_MULTI) && info.extended_images) {
 		tex_num_images[IMAGE_DATA_TYPE_BYTE4] = TEX_NUM_BYTE4_IMAGES_CUDA_KEPLER;
 		tex_num_images[IMAGE_DATA_TYPE_FLOAT4] = TEX_NUM_FLOAT4_IMAGES_CUDA_KEPLER;
+		tex_num_images[IMAGE_DATA_TYPE_FLOAT] = TEX_NUM_FLOAT_IMAGES_CUDA_KEPLER;
 		tex_image_byte4_start = TEX_IMAGE_BYTE4_START_CUDA_KELPER;
+		tex_image_float_start = TEX_IMAGE_FLOAT_START_CUDA_KELPER;
 	}
 	/* OpenCL */
 	else if(info.pack_images) {
 		tex_num_images[IMAGE_DATA_TYPE_BYTE4] = TEX_NUM_BYTE4_IMAGES_OPENCL;
 		tex_num_images[IMAGE_DATA_TYPE_FLOAT4] = TEX_NUM_FLOAT4_IMAGES_OPENCL;
+		tex_num_images[IMAGE_DATA_TYPE_FLOAT] = TEX_NUM_FLOAT_IMAGES_OPENCL;
 		tex_image_byte4_start = TEX_IMAGE_BYTE4_START_OPENCL;
+		tex_image_float_start = TEX_IMAGE_FLOAT_START_OPENCL;
 	}
 	/* Should never happen */
 	else {
 		tex_num_images[IMAGE_DATA_TYPE_BYTE4] = 0;
 		tex_num_images[IMAGE_DATA_TYPE_FLOAT4] = 0;
+		tex_num_images[IMAGE_DATA_TYPE_FLOAT] = 0;
 		tex_image_byte4_start = 0;
+		tex_image_float_start = 0;
 		assert(0);
 	}
 }
@@ -106,21 +115,30 @@ bool ImageManager::set_animation_frame_update(int frame)
 	return false;
 }
 
-bool ImageManager::is_float_image(const string& filename, void *builtin_data, bool& is_linear)
+ImageManager::ImageDataType ImageManager::get_image_metadata(const string& filename,
+                                                             void *builtin_data,
+                                                             bool& is_linear)
 {
 	bool is_float = false;
 	is_linear = false;
+	int channels = 4;
 
 	if(builtin_data) {
 		if(builtin_image_info_cb) {
-			int width, height, depth, channels;
+			int width, height, depth;
 			builtin_image_info_cb(filename, builtin_data, is_float, width, height, depth, channels);
 		}
 
-		if(is_float)
+		if(is_float) {
 			is_linear = true;
 
-		return is_float;
+			if(channels > 1)
+				return IMAGE_DATA_TYPE_FLOAT4;
+			else
+				return IMAGE_DATA_TYPE_FLOAT;
+		}
+		else
+			return IMAGE_DATA_TYPE_BYTE4;
 	}
 
 	ImageInput *in = ImageInput::create(filename);
@@ -143,6 +161,8 @@ bool ImageManager::is_float_image(const string& filename, void *builtin_data, bo
 				}
 			}
 
+			channels = spec.nchannels;
+
 			/* basic color space detection, not great but better than nothing
 			 * before we do OpenColorIO integration */
 			if(is_float) {
@@ -166,20 +186,34 @@ bool ImageManager::is_float_image(const string& filename, void *builtin_data, bo
 		delete in;
 	}
 
-	return is_float;
+	if(is_float) {
+		if(channels > 1)
+			return IMAGE_DATA_TYPE_FLOAT4;
+		else
+			return IMAGE_DATA_TYPE_FLOAT;
+	}
+	else
+		return IMAGE_DATA_TYPE_BYTE4;
 }
 
 int ImageManager::type_index_to_flattened_slot(int slot, ImageDataType type)
 {
 	if(type == IMAGE_DATA_TYPE_BYTE4)
 		return slot + tex_image_byte4_start;
+	else if(type == IMAGE_DATA_TYPE_FLOAT)
+		return slot + tex_image_float_start;
 	else
 		return slot;
 }
 
 int ImageManager::flattened_slot_to_type_index(int flat_slot, ImageDataType *type)
 {
-	if(flat_slot >= tex_image_byte4_start) {
+	if(flat_slot >= tex_image_float_start)
+	{
+		*type = IMAGE_DATA_TYPE_FLOAT;
+		return flat_slot - tex_image_float_start;
+	}
+	else if(flat_slot >= tex_image_byte4_start) {
 		*type = IMAGE_DATA_TYPE_BYTE4;
 		return flat_slot - tex_image_byte4_start;
 	}
@@ -192,9 +226,11 @@ int ImageManager::flattened_slot_to_type_index(int flat_slot, ImageDataType *typ
 string ImageManager::name_from_type(int type)
 {
 	if(type == IMAGE_DATA_TYPE_FLOAT4)
+		return "float4";
+	else if(type == IMAGE_DATA_TYPE_FLOAT)
 		return "float";
 	else
-		return "byte";
+		return "byte4";
 }
 
 static bool image_equals(ImageManager::Image *image,
@@ -222,10 +258,15 @@ int ImageManager::add_image(const string& filename,
 	Image *img;
 	size_t slot;
 
-	/* Load image info and find out if we need a float texture. */
-	is_float = is_float_image(filename, builtin_data, is_linear);
+	ImageDataType type = get_image_metadata(filename, builtin_data, is_linear);
+
+	/* Do we have a float? */
+	if(type == IMAGE_DATA_TYPE_FLOAT || type == IMAGE_DATA_TYPE_FLOAT4)
+		is_float = true;
 
-	ImageDataType type = is_float? IMAGE_DATA_TYPE_FLOAT4 : IMAGE_DATA_TYPE_BYTE4;
+	/* No float textures on GPU yet */
+	if(type == IMAGE_DATA_TYPE_FLOAT && tex_num_images[type] == 0)
+		type = IMAGE_DATA_TYPE_FLOAT4;
 
 	/* Fnd existing image. */
 	for(slot = 0; slot < images[type].size(); slot++) {
@@ -349,19 +390,16 @@ void ImageManager::tag_reload_image(const string& filename,
 	}
 }
 
-bool ImageManager::file_load_image(Image *img, device_vector<uchar4>& tex_img)
+bool ImageManager::file_load_image_generic(Image *img, ImageInput **in, int &width, int &height, int &depth, int &components)
 {
 	if(img->filename == "")
 		return false;
 
-	ImageInput *in = NULL;
-	int width, height, depth, components;
-
 	if(!img->builtin_data) {
 		/* load image from file through OIIO */
-		in = ImageInput::create(img->filename);
+		*in = ImageInput::create(img->filename);
 
-		if(!in)
+		if(!*in)
 			return false;
 
 		ImageSpec spec = ImageSpec();
@@ -370,8 +408,9 @@ bool ImageManager::file_load_image(Image *img, device_vector<uchar4>& tex_img)
 		if(img->use_alpha == false)
 			config.attribute("oiio:UnassociatedAlpha", 1);
 
-		if(!in->open(img->filename, spec, config)) {
-			delete in;
+		if(!(*in)->open(img->filename, spec, config)) {
+			delete *in;
+			*in = NULL;
 			return false;
 		}
 
@@ -391,14 +430,26 @@ bool ImageManager::file_load_image(Image *img, device_vector<uchar4>& tex_img)
 
 	/* we only handle certain number of components */
 	if(!(components >= 1 && components <= 4)) {
-		if(in) {
-			in->close();
-			delete in;
+		if(*in) {
+			(*in)->close();
+			delete *in;
+			*in = NULL;
 		}
 
 		return false;
 	}
 
+	return true;
+}
+
+bool ImageManager::file_load_byte4_image(Image *img, device_vector<uchar4>& tex_img)
+{
+	ImageInput *in = NULL;
+	int width, height, depth, components;
+
+	if(!file_load_image_generic(img, &in, width, height, depth, components))
+		return false;
+
 	/* read RGBA pixels */
 	uchar *pixels = (uchar*)tex_img.resize(width, height, depth);
 	if(pixels == NULL) {
@@ -476,54 +527,13 @@ bool ImageManager::file_load_image(Image *img, device_vector<uchar4>& tex_img)
 	return true;
 }
 
-bool ImageManager::file_load_float_image(Image *img, device_vector<float4>& tex_img)
+bool ImageManager::file_load_float4_image(Image *img, device_vector<float4>& tex_img)
 {
-	if(img->filename == "")
-		return false;
-
 	ImageInput *in = NULL;
 	int width, height, depth, components;
 
-	if(!img->builtin_data) {
-		/* load image from file through OIIO */
-		in = ImageInput::create(img->filename);
-
-		if(!in)
-			return false;
-
-		ImageSpec spec = ImageSpec();
-		ImageSpec config = ImageSpec();
-
-		if(img->use_alpha == false)
-			config.attribute("oiio:UnassociatedAlpha",1);
-
-		if(!in->open(img->filename, spec, config)) {
-			delete in;
-			return false;
-		}
-
-		/* we only handle certain number of components */
-		width = spec.width;
-		height = spec.height;
-		depth = spec.depth;
-		components = spec.nchannels;
-	}
-	else {
-		/* load image using builtin images callbacks */
-		if(!builtin_image_info_cb || !builtin_image_float_pixels_cb)
-			return false;
-
-		bool is_float;
-		builtin_image_info_cb(img->filename, img->builtin_data, is_float, width, height, depth, components);
-	}
-
-	if(components < 1 || width == 0 || height == 0) {
-		if(in) {
-			in->close();
-			delete in;
-		}
+	if(!file_load_image_generic(img, &in, width, height, depth, components))
 		return false;
-	}
 
 	/* read RGBA pixels */
 	float *pixels = (float*)tex_img.resize(width, height, depth);
@@ -622,6 +632,46 @@ bool ImageManager::file_load_float_image(Image *img, device_vector<float4>& tex_
 	return true;
 }
 
+bool ImageManager::file_load_float_image(Image *img, device_vector<float>& tex_img)
+{
+	ImageInput *in = NULL;
+	int width, height, depth, components;
+
+	if(!file_load_image_generic(img, &in, width, height, depth, components))
+		return false;
+
+	/* read BW pixels */
+	float *pixels = (float*)tex_img.resize(width, height, depth);
+	if(pixels == NULL) {
+		return false;
+	}
+
+	if(in) {
+		float *readpixels = pixels;
+
+		if(depth <= 1) {
+			int scanlinesize = width*components*sizeof(float);
+
+			in->read_image(TypeDesc::FLOAT,
+			               (uchar*)readpixels + (height-1)*scanlinesize,
+			               AutoStride,
+			               -scanlinesize,
+			               AutoStride);
+		}
+		else {
+			in->read_image(TypeDesc::FLOAT, (uchar*)readpixels);
+		}
+
+		in->close();
+		delete in;
+	}
+	else {
+		builtin_image_float_pixels_cb(img->filename, img->builtin_data, pixels);
+	}
+
+	return true;
+}
+
 void ImageManager::device_load_image(Device *device, DeviceScene *dscene, ImageDataType type, int slot, Progress *progress)
 {
 	if(progress->get_cancel())
@@ -635,6 +685,17 @@ void ImageManager::device_load_image(Device *device, DeviceScene *dscene, ImageD
 	string filename = path_filename(images[type][slot]->filename);
 	progress->set_status("Updating Images", "Loading " + filename);
 
+	/* Slot assignment */
+	int flat_slot = type_index_to_flattened_slot(slot, type);
+
+	string name;
+	if(flat_slot >= 100)
+		name = string_printf("__tex_image_%s_%d", name_from_type(type).c_str(), flat_slot);
+	else if(flat_slot >= 10)
+		name = string_printf("__tex_image_%s_0%d", name_from_type(type).c_str(), flat_slot);
+	else
+		name = string_printf("__tex_image_%s_00%d", name_from_type(type).c_str(), flat_slot);
+
 	if(type == IMAGE_DATA_TYPE_FLOAT4) {
 		device_vector<float4>& tex_img = dscene->tex_float4_image[slot];
 
@@ -643,7 +704,7 @@ void ImageManager::device_load_image(Device *device, DeviceScene *dscene, ImageD
 			device->tex_free(tex_img);
 		}
 
-		if(!file_load_float_image(img, tex_img)) {
+		if(!file_load_float4_image(img, tex_img)) {
 			/* on failure to load, we set a 1x1 pixels pink image */
 			float *pixels = (float*)tex_img.resize(1, 1);
 
@@ -653,12 +714,28 @@ void ImageManager::device_load_image(Device *device, DeviceScene *dscene, ImageD
 			pixels[3] = TEX_IMAGE_MISSING_A;
 		}
 
-		string name;
+		if(!pack_images) {
+			thread_scoped_lock device_lock(device_mutex);
+			device->tex_alloc(name.c_str(),
+			                  tex_img,
+			                  img->interpolation,
+			                  img->extension);
+		}
+	}
+	else if(type == IMAGE_DATA_TYPE_FLOAT) {
+		device_vector<float>& tex_img = dscene->tex_float_image[slot];
+
+		if(tex_img.device_pointer) {
+			thread_scoped_lock device_lock(device_mutex);
+			device->tex_free(tex_img);
+		}
+
+		if(!file_load_float_image(img, tex_img)) {
+			/* on failure to load, we set a 1x1 pixels pink image */
+			float *pixels = (float*)tex_img.resize(1, 1);
 
-		int flat_slot = type_index_to_flattened_slot(slot, type);
-		if(flat_slot >= 100) name = string_printf("__tex_image_float4_%d", flat_slot);
-		else if(flat_slot >= 10) name = string_printf("__tex_image_float4_0%d", flat_slot);
-		else name = string_printf("__tex_image_float4_00%d", flat_slot);
+			pixels[0] = TEX_IMAGE_MISSING_R;
+		}
 
 		if(!pack_images) {
 			thread_scoped_lock device_lock(device_mutex);
@@ -676,7 +753,7 @@ void ImageManager::device_load_image(Device *device, DeviceScene *dscene, ImageD
 			device->tex_free(tex_img);
 		}
 
-		if(!file_load_image(img, tex_img)) {
+		if(!file_load_byte4_image(img, tex_img)) {
 			/* on failure to load, we set a 1x1 pixels pink image */
 			uchar *pixels = (uchar*)tex_img.resize(1, 1);
 
@@ -686,13 +763,6 @@ void ImageManager::device_load_image(Device *device, DeviceScene *dscene, ImageD
 			pixels[3] = (TEX_IMAGE_MISSING_A * 255);
 		}
 
-		string name;
-
-		int flat_slot = type_index_to_flattened_slot(slot, type);
-		if(flat_slot >= 100) name = string_printf("__tex_image_byte4_%d", flat_slot);
-		else if(flat_slot >= 10) name = string_printf("__tex_image_byte4_0%d", flat_slot);
-		else name = string_printf("__tex_image_byte4_00%d", flat_slot);
-
 		if(!pack_images) {
 			thread_scoped_lock device_lock(device_mutex);
 			device->tex_alloc(name.c_str(),
@@ -729,6 +799,19 @@ void ImageManager::device_free_image(Device *device, DeviceScene *dscene, ImageD
 			delete images[type][slot];
 			images[type][slot] = NULL;
 		}
+		else if(type == IMAGE_DATA_TYPE_FLOAT) {
+			device_vector<float>& tex_img = dscene->tex_float_image[slot];
+
+			if(tex_img.device_pointer) {
+				thread_scoped_lock device_lock(device_mutex);
+				device->tex_free(tex_img);
+			}
+
+			tex_img.clear();
+
+			delete images[type][slot];
+			images[type][slot] = NULL;
+		}
 		else {
 			device_vector<uchar4>& tex_img = dscene->tex_byte4_image[slot];
 
diff --git a/intern/cycles/render/image.h b/intern/cycles/render/image.h
index 02dc189b5ec..cf5a6e9523f 100644
--- a/intern/cycles/render/image.h
+++ b/intern/cycles/render/image.h
@@ -20,6 +20,7 @@
 #include "device.h"
 #include "device_memory.h"
 
+#include "util_image.h"
 #include "util_string.h"
 #include "util_thread.h"
 #include "util_vector.h"
@@ -38,6 +39,7 @@ public:
 	enum ImageDataType {
 		IMAGE_DATA_TYPE_FLOAT4 = 0,
 		IMAGE_DATA_TYPE_BYTE4 = 1,
+		IMAGE_DATA_TYPE_FLOAT = 2,
 
 		IMAGE_DATA_NUM_TYPES
 	};
@@ -60,7 +62,7 @@ public:
 	                      void *builtin_data,
 	                      InterpolationType interpolation,
 	                      ExtensionType extension);
-	bool is_float_image(const string& filename, void *builtin_data, bool& is_linear);
+	ImageDataType get_image_metadata(const string& filename, void *builtin_data, bool& is_linear);
 
 	void device_update(Device *device, DeviceScene *dscene, Progress& progress);
 	void device_update_slot(Device *device, DeviceScene *dscene, int flat_slot, Progress *progress);
@@ -94,6 +96,7 @@ public:
 private:
 	int tex_num_images[IMAGE_DATA_NUM_TYPES];
 	int tex_image_byte4_start;
+	int tex_image_float_start;
 	thread_mutex device_mutex;
 	int animation_frame;
 
@@ -101,8 +104,10 @@ private:
 	void *osl_texture_system;
 	bool pack_images;
 
-	bool file_load_image(Image *img, device_vector<uchar4>& tex_img);
-	bool file_load_float_image(Image *img, device_vector<float4>& tex_img);
+	bool file_load_image_generic(Image *img, ImageInput **in, int &width, int &height, int &depth, int &components);
+	bool file_load_byte4_image(Image *img, device_vector<uchar4>& tex_img);
+	bool file_load_float4_image(Image *img, device_vector<float4>& tex_img);
+	bool file_load_float_image(Image *img, device_vector<float>& tex_img);
 
 	int type_index_to_flattened_slot(int slot, ImageDataType type);
 	int flattened_slot_to_type_index(int flat_slot, ImageDataType *type);
diff --git a/intern/cycles/render/nodes.cpp b/intern/cycles/render/nodes.cpp
index 49d53def7a9..e612a2d36d6 100644
--- a/intern/cycles/render/nodes.cpp
+++ b/intern/cycles/render/nodes.cpp
@@ -349,7 +349,10 @@ void ImageTextureNode::compile(OSLCompiler& compiler)
 	image_manager = compiler.image_manager;
 	if(is_float == -1) {
 		if(builtin_data == NULL) {
-			is_float = (int)image_manager->is_float_image(filename, NULL, is_linear);
+			ImageManager::ImageDataType type;
+			type = image_manager->get_image_metadata(filename, NULL, is_linear);
+			if(type == ImageManager::IMAGE_DATA_TYPE_FLOAT || type == ImageManager::IMAGE_DATA_TYPE_FLOAT4)
+				is_float = 1;
 		}
 		else {
 			bool is_float_bool;
@@ -533,7 +536,10 @@ void EnvironmentTextureNode::compile(OSLCompiler& compiler)
 	image_manager = compiler.image_manager;
 	if(is_float == -1) {
 		if(builtin_data == NULL) {
-			is_float = (int)image_manager->is_float_image(filename, NULL, is_linear);
+			ImageManager::ImageDataType type;
+			type = image_manager->get_image_metadata(filename, NULL, is_linear);
+			if(type == ImageManager::IMAGE_DATA_TYPE_FLOAT || type == ImageManager::IMAGE_DATA_TYPE_FLOAT4)
+				is_float = 1;
 		}
 		else {
 			bool is_float_bool;
diff --git a/intern/cycles/render/scene.h b/intern/cycles/render/scene.h
index 455053fb3f6..34050851d8e 100644
--- a/intern/cycles/render/scene.h
+++ b/intern/cycles/render/scene.h
@@ -111,6 +111,7 @@ public:
 	/* cpu images */
 	device_vector<uchar4> tex_byte4_image[TEX_NUM_BYTE4_IMAGES_CPU];
 	device_vector<float4> tex_float4_image[TEX_NUM_FLOAT4_IMAGES_CPU];
+	device_vector<float> tex_float_image[TEX_NUM_FLOAT_IMAGES_CPU];
 
 	/* opencl images */
 	device_vector<uchar4> tex_image_byte4_packed;