/*

    ......... 2015 Ivan Mahonin

    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 3 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, see <http://www.gnu.org/licenses/>.

*/

#include <fstream>

#include "utils.h"

#include "glcontext.h"

using namespace std;

Vector Utils::get_frame_size() {

	int vp[4] = {};

	glGetIntegerv(GL_VIEWPORT, vp);

	return Vector((Real)vp[2], (Real)vp[3]);

}

void Utils::save_rgba(

	const void *buffer,

	int width,

	int height,

	bool flip,

	const string &filename )

{

	// create file

	ofstream f(("results/" + filename).c_str(), ofstream::out | ofstream::trunc | ofstream::binary);

	// write header

	unsigned char targa_header[] = {

		0,    // Length of the image ID field (0 - no ID field)

		0,    // Whether a color map is included (0 - no colormap)

		2,    // Compression and color types (2 - uncompressed true-color image)

		0, 0, 0, 0, 0, // Color map specification (not need for us)

		0, 0, // X-origin

		0, 0, // Y-origin

		(unsigned char)(width & 0xff), // Image width

		(unsigned char)(width >> 8),

		(unsigned char)(height & 0xff), // Image height

		(unsigned char)(height >> 8),

		32,   // Bits per pixel

		0     // Image descriptor (keep zero for capability)

	};

	f.write((char*)targa_header, sizeof(targa_header));

	// write data

	if (flip) {

		int line_size = 4*width;

		const char *end = (char*)buffer;

		const char *current = end + height*line_size;

		while(current > end) {

			current -= line_size;

			f.write(current, line_size);

		}

	} else {

		f.write((const char*)buffer, 4*width*height);

	}

}

void Utils::save_viewport(const string &filename) {

	glFinish();

	GLint  vp[4] = {};

	glGetIntegerv(GL_VIEWPORT, vp);

	GLint draw_buffer = 0, read_buffer = 0;

	glGetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, &draw_buffer);

	glGetIntegerv(GL_READ_FRAMEBUFFER_BINDING, &read_buffer);

	if (draw_buffer != read_buffer) {

		glBindFramebuffer(GL_DRAW_FRAMEBUFFER, (GLuint)read_buffer);

		glBindFramebuffer(GL_READ_FRAMEBUFFER, (GLuint)draw_buffer);

		glBlitFramebuffer(vp[0], vp[1], vp[2], vp[3], vp[0], vp[1], vp[2], vp[3], GL_COLOR_BUFFER_BIT, GL_NEAREST);

		glFinish();

		glBindFramebuffer(GL_DRAW_FRAMEBUFFER, (GLuint)draw_buffer);

		glBindFramebuffer(GL_READ_FRAMEBUFFER, (GLuint)read_buffer);

	}

	char *buffer = new char[vp[2]*vp[3]*4];

	glReadPixels(vp[0], vp[1], vp[2], vp[3], GL_BGRA, GL_UNSIGNED_BYTE, buffer);

	save_rgba(buffer, vp[2], vp[3], false, filename);

	delete buffer;

}

void Utils::save_surface(const Surface &surface, const string &filename) {

	unsigned char *buffer = new unsigned char[4*surface.count()];

	unsigned char *j = buffer;

	for(Color *i = surface.data, *end = i + surface.count(); i != end; ++i, j += 4) {

		j[0] = (unsigned char)roundf(max(0.f, min(1.f, i->b))*255.f);

		j[1] = (unsigned char)roundf(max(0.f, min(1.f, i->g))*255.f);

		j[2] = (unsigned char)roundf(max(0.f, min(1.f, i->r))*255.f);

		j[3] = (unsigned char)roundf(max(0.f, min(1.f, i->a))*255.f);

	}

	save_rgba(buffer, surface.width, surface.height, false, filename);

	delete buffer;

}