/*
 * Copyright 2011-2014 Blender Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "render/bake.h"
#include "render/integrator.h"

CCL_NAMESPACE_BEGIN

BakeData::BakeData(const int object, const size_t tri_offset, const size_t num_pixels):
m_object(object),
m_tri_offset(tri_offset),
m_num_pixels(num_pixels)
{
	m_primitive.resize(num_pixels);
	m_u.resize(num_pixels);
	m_v.resize(num_pixels);
	m_dudx.resize(num_pixels);
	m_dudy.resize(num_pixels);
	m_dvdx.resize(num_pixels);
	m_dvdy.resize(num_pixels);
}

BakeData::~BakeData()
{
	m_primitive.clear();
	m_u.clear();
	m_v.clear();
	m_dudx.clear();
	m_dudy.clear();
	m_dvdx.clear();
	m_dvdy.clear();
}

void BakeData::set(int i, int prim, float uv[2], float dudx, float dudy, float dvdx, float dvdy)
{
	m_primitive[i] = (prim == -1 ? -1 : m_tri_offset + prim);
	m_u[i] = uv[0];
	m_v[i] = uv[1];
	m_dudx[i] = dudx;
	m_dudy[i] = dudy;
	m_dvdx[i] = dvdx;
	m_dvdy[i] = dvdy;
}

void BakeData::set_null(int i)
{
	m_primitive[i] = -1;
}

int BakeData::object()
{
	return m_object;
}

size_t BakeData::size()
{
	return m_num_pixels;
}

bool BakeData::is_valid(int i)
{
	return m_primitive[i] != -1;
}

uint4 BakeData::data(int i)
{
	return make_uint4(
		m_object,
		m_primitive[i],
		__float_as_int(m_u[i]),
		__float_as_int(m_v[i])
		);
}

uint4 BakeData::differentials(int i)
{
	return make_uint4(
		  __float_as_int(m_dudx[i]),
		  __float_as_int(m_dudy[i]),
		  __float_as_int(m_dvdx[i]),
		  __float_as_int(m_dvdy[i])
		  );
}

BakeManager::BakeManager()
{
	m_bake_data = NULL;
	m_is_baking = false;
	need_update = true;
	m_shader_limit = 512 * 512;
}

BakeManager::~BakeManager()
{
	if(m_bake_data)
		delete m_bake_data;
}

bool BakeManager::get_baking()
{
	return m_is_baking;
}

void BakeManager::set_baking(const bool value)
{
	m_is_baking = value;
}

BakeData *BakeManager::init(const int object, const size_t tri_offset, const size_t num_pixels)
{
	m_bake_data = new BakeData(object, tri_offset, num_pixels);
	return m_bake_data;
}

void BakeManager::set_shader_limit(const size_t x, const size_t y)
{
	m_shader_limit = x * y;
	m_shader_limit = (size_t)pow(2, ceil(log(m_shader_limit)/log(2)));
}

bool BakeManager::bake(Device *device, DeviceScene *dscene, Scene *scene, Progress& progress, ShaderEvalType shader_type, const int pass_filter, BakeData *bake_data, float result[])
{
	size_t num_pixels = bake_data->size();

	int num_samples = is_aa_pass(shader_type)? scene->integrator->aa_samples : 1;

	/* calculate the total pixel samples for the progress bar */
	total_pixel_samples = 0;
	for(size_t shader_offset = 0; shader_offset < num_pixels; shader_offset += m_shader_limit) {
		size_t shader_size = (size_t)fminf(num_pixels - shader_offset, m_shader_limit);
		total_pixel_samples += shader_size * num_samples;
	}
	progress.reset_sample();
	progress.set_total_pixel_samples(total_pixel_samples);

	for(size_t shader_offset = 0; shader_offset < num_pixels; shader_offset += m_shader_limit) {
		size_t shader_size = (size_t)fminf(num_pixels - shader_offset, m_shader_limit);

		/* setup input for device task */
		device_vector<uint4> d_input;
		uint4 *d_input_data = d_input.resize(shader_size * 2);
		size_t d_input_size = 0;

		for(size_t i = shader_offset; i < (shader_offset + shader_size); i++) {
			d_input_data[d_input_size++] = bake_data->data(i);
			d_input_data[d_input_size++] = bake_data->differentials(i);
		}

		if(d_input_size == 0) {
			m_is_baking = false;
			return false;
		}

		/* run device task */
		device_vector<float4> d_output;
		d_output.resize(shader_size);

		/* needs to be up to data for attribute access */
		device->const_copy_to("__data", &dscene->data, sizeof(dscene->data));

		device->mem_alloc("bake_input", d_input, MEM_READ_ONLY);
		device->mem_copy_to(d_input);
		device->mem_alloc("bake_output", d_output, MEM_READ_WRITE);
		device->mem_zero(d_output);

		DeviceTask task(DeviceTask::SHADER);
		task.shader_input = d_input.device_pointer;
		task.shader_output = d_output.device_pointer;
		task.shader_eval_type = shader_type;
		task.shader_filter = pass_filter;
		task.shader_x = 0;
		task.offset = shader_offset;
		task.shader_w = d_output.size();
		task.num_samples = num_samples;
		task.get_cancel = function_bind(&Progress::get_cancel, &progress);
		task.update_progress_sample = function_bind(&Progress::add_samples_update, &progress, _1, _2);

		device->task_add(task);
		device->task_wait();

		if(progress.get_cancel()) {
			device->mem_free(d_input);
			device->mem_free(d_output);
			m_is_baking = false;
			return false;
		}

		device->mem_copy_from(d_output, 0, 1, d_output.size(), sizeof(float4));
		device->mem_free(d_input);
		device->mem_free(d_output);

		/* read result */
		int k = 0;

		float4 *offset = (float4*)d_output.data_pointer;

		size_t depth = 4;
		for(size_t i=shader_offset; i < (shader_offset + shader_size); i++) {
			size_t index = i * depth;
			float4 out = offset[k++];

			if(bake_data->is_valid(i)) {
				for(size_t j=0; j < 4; j++) {
					result[index + j] = out[j];
				}
			}
		}
	}

	m_is_baking = false;
	return true;
}

void BakeManager::device_update(Device * /*device*/,
                                DeviceScene * /*dscene*/,
                                Scene * /*scene*/,
                                Progress& progress)
{
	if(!need_update)
		return;

	if(progress.get_cancel()) return;

	need_update = false;
}

void BakeManager::device_free(Device * /*device*/, DeviceScene * /*dscene*/)
{
}

bool BakeManager::is_aa_pass(ShaderEvalType type)
{
	switch(type) {
		case SHADER_EVAL_UV:
		case SHADER_EVAL_NORMAL:
			return false;
		default:
			return true;
	}
}

/* Keep it synced with kernel_bake.h logic */
int BakeManager::shader_type_to_pass_filter(ShaderEvalType type, const int pass_filter)
{
	const int component_flags = pass_filter & (BAKE_FILTER_DIRECT | BAKE_FILTER_INDIRECT | BAKE_FILTER_COLOR);

	switch(type) {
		case SHADER_EVAL_AO:
			return BAKE_FILTER_AO;
		case SHADER_EVAL_SHADOW:
			return BAKE_FILTER_DIRECT;
		case SHADER_EVAL_DIFFUSE:
			return BAKE_FILTER_DIFFUSE | component_flags;
		case SHADER_EVAL_GLOSSY:
			return BAKE_FILTER_GLOSSY | component_flags;
		case SHADER_EVAL_TRANSMISSION:
			return BAKE_FILTER_TRANSMISSION | component_flags;
		case SHADER_EVAL_SUBSURFACE:
			return BAKE_FILTER_SUBSURFACE | component_flags;
		case SHADER_EVAL_COMBINED:
			return pass_filter;
		default:
			return 0;
	}
}

CCL_NAMESPACE_END