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blender-archive/source/blender/compositor/operations/COM_MapUVOperation.cc
2021-10-13 23:41:14 +02:00

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C++

/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright 2011, Blender Foundation.
*/
#include "COM_MapUVOperation.h"
namespace blender::compositor {
MapUVOperation::MapUVOperation()
{
this->add_input_socket(DataType::Color, ResizeMode::Align);
this->add_input_socket(DataType::Vector);
this->add_output_socket(DataType::Color);
alpha_ = 0.0f;
flags_.complex = true;
set_canvas_input_index(UV_INPUT_INDEX);
inputUVProgram_ = nullptr;
input_color_program_ = nullptr;
}
void MapUVOperation::init_data()
{
NodeOperation *image_input = get_input_operation(IMAGE_INPUT_INDEX);
image_width_ = image_input->get_width();
image_height_ = image_input->get_height();
NodeOperation *uv_input = get_input_operation(UV_INPUT_INDEX);
uv_width_ = uv_input->get_width();
uv_height_ = uv_input->get_height();
}
void MapUVOperation::init_execution()
{
input_color_program_ = this->get_input_socket_reader(0);
inputUVProgram_ = this->get_input_socket_reader(1);
if (execution_model_ == eExecutionModel::Tiled) {
uv_input_read_fn_ = [=](float x, float y, float *out) {
inputUVProgram_->read_sampled(out, x, y, PixelSampler::Bilinear);
};
}
}
void MapUVOperation::execute_pixel_sampled(float output[4],
float x,
float y,
PixelSampler /*sampler*/)
{
float xy[2] = {x, y};
float uv[2], deriv[2][2], alpha;
pixel_transform(xy, uv, deriv, alpha);
if (alpha == 0.0f) {
zero_v4(output);
return;
}
/* EWA filtering */
input_color_program_->read_filtered(output, uv[0], uv[1], deriv[0], deriv[1]);
/* UV to alpha threshold */
const float threshold = alpha_ * 0.05f;
/* XXX alpha threshold is used to fade out pixels on boundaries with invalid derivatives.
* this calculation is not very well defined, should be looked into if it becomes a problem ...
*/
float du = len_v2(deriv[0]);
float dv = len_v2(deriv[1]);
float factor = 1.0f - threshold * (du / input_color_program_->get_width() +
dv / input_color_program_->get_height());
if (factor < 0.0f) {
alpha = 0.0f;
}
else {
alpha *= factor;
}
/* "premul" */
if (alpha < 1.0f) {
mul_v4_fl(output, alpha);
}
}
bool MapUVOperation::read_uv(float x, float y, float &r_u, float &r_v, float &r_alpha)
{
if (x < 0.0f || x >= uv_width_ || y < 0.0f || y >= uv_height_) {
r_u = 0.0f;
r_v = 0.0f;
r_alpha = 0.0f;
return false;
}
float vector[3];
uv_input_read_fn_(x, y, vector);
r_u = vector[0] * image_width_;
r_v = vector[1] * image_height_;
r_alpha = vector[2];
return true;
}
void MapUVOperation::pixel_transform(const float xy[2],
float r_uv[2],
float r_deriv[2][2],
float &r_alpha)
{
float uv[2], alpha; /* temporary variables for derivative estimation */
int num;
read_uv(xy[0], xy[1], r_uv[0], r_uv[1], r_alpha);
/* Estimate partial derivatives using 1-pixel offsets */
const float epsilon[2] = {1.0f, 1.0f};
zero_v2(r_deriv[0]);
zero_v2(r_deriv[1]);
num = 0;
if (read_uv(xy[0] + epsilon[0], xy[1], uv[0], uv[1], alpha)) {
r_deriv[0][0] += uv[0] - r_uv[0];
r_deriv[1][0] += uv[1] - r_uv[1];
num++;
}
if (read_uv(xy[0] - epsilon[0], xy[1], uv[0], uv[1], alpha)) {
r_deriv[0][0] += r_uv[0] - uv[0];
r_deriv[1][0] += r_uv[1] - uv[1];
num++;
}
if (num > 0) {
float numinv = 1.0f / (float)num;
r_deriv[0][0] *= numinv;
r_deriv[1][0] *= numinv;
}
num = 0;
if (read_uv(xy[0], xy[1] + epsilon[1], uv[0], uv[1], alpha)) {
r_deriv[0][1] += uv[0] - r_uv[0];
r_deriv[1][1] += uv[1] - r_uv[1];
num++;
}
if (read_uv(xy[0], xy[1] - epsilon[1], uv[0], uv[1], alpha)) {
r_deriv[0][1] += r_uv[0] - uv[0];
r_deriv[1][1] += r_uv[1] - uv[1];
num++;
}
if (num > 0) {
float numinv = 1.0f / (float)num;
r_deriv[0][1] *= numinv;
r_deriv[1][1] *= numinv;
}
}
void MapUVOperation::deinit_execution()
{
inputUVProgram_ = nullptr;
input_color_program_ = nullptr;
}
bool MapUVOperation::determine_depending_area_of_interest(rcti *input,
ReadBufferOperation *read_operation,
rcti *output)
{
rcti color_input;
rcti uv_input;
NodeOperation *operation = nullptr;
/* the uv buffer only needs a 3x3 buffer. The image needs whole buffer */
operation = get_input_operation(0);
color_input.xmax = operation->get_width();
color_input.xmin = 0;
color_input.ymax = operation->get_height();
color_input.ymin = 0;
if (operation->determine_depending_area_of_interest(&color_input, read_operation, output)) {
return true;
}
operation = get_input_operation(1);
uv_input.xmax = input->xmax + 1;
uv_input.xmin = input->xmin - 1;
uv_input.ymax = input->ymax + 1;
uv_input.ymin = input->ymin - 1;
if (operation->determine_depending_area_of_interest(&uv_input, read_operation, output)) {
return true;
}
return false;
}
void MapUVOperation::get_area_of_interest(const int input_idx,
const rcti &output_area,
rcti &r_input_area)
{
switch (input_idx) {
case IMAGE_INPUT_INDEX: {
r_input_area = get_input_operation(IMAGE_INPUT_INDEX)->get_canvas();
break;
}
case UV_INPUT_INDEX: {
r_input_area = output_area;
expand_area_for_sampler(r_input_area, PixelSampler::Bilinear);
break;
}
}
}
void MapUVOperation::update_memory_buffer_started(MemoryBuffer *UNUSED(output),
const rcti &UNUSED(area),
Span<MemoryBuffer *> inputs)
{
const MemoryBuffer *uv_input = inputs[UV_INPUT_INDEX];
uv_input_read_fn_ = [=](float x, float y, float *out) {
uv_input->read_elem_bilinear(x, y, out);
};
}
void MapUVOperation::update_memory_buffer_partial(MemoryBuffer *output,
const rcti &area,
Span<MemoryBuffer *> inputs)
{
const MemoryBuffer *input_image = inputs[IMAGE_INPUT_INDEX];
for (BuffersIterator<float> it = output->iterate_with({}, area); !it.is_end(); ++it) {
float xy[2] = {(float)it.x, (float)it.y};
float uv[2];
float deriv[2][2];
float alpha;
pixel_transform(xy, uv, deriv, alpha);
if (alpha == 0.0f) {
zero_v4(it.out);
continue;
}
/* EWA filtering. */
input_image->read_elem_filtered(uv[0], uv[1], deriv[0], deriv[1], it.out);
/* UV to alpha threshold. */
const float threshold = alpha_ * 0.05f;
/* XXX alpha threshold is used to fade out pixels on boundaries with invalid derivatives.
* this calculation is not very well defined, should be looked into if it becomes a problem ...
*/
const float du = len_v2(deriv[0]);
const float dv = len_v2(deriv[1]);
const float factor = 1.0f - threshold * (du / image_width_ + dv / image_height_);
if (factor < 0.0f) {
alpha = 0.0f;
}
else {
alpha *= factor;
}
/* "premul" */
if (alpha < 1.0f) {
mul_v4_fl(it.out, alpha);
}
}
}
} // namespace blender::compositor