/*
	QGL GLRendererBase
	Ivan Pelipenko peri4ko@yandex.ru

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Lesser 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 Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "glrendererbase.h"
#include "globject.h"
#include "qglview.h"


GLRendererBase::GLRendererBase(QGLView * view_): view(view_) {
	white_image = QImage(1, 1, QImage::Format_ARGB32);
	white_image.fill(0xFFFFFFFF);
	white_image_id = 0;
	violent_image = QImage(1, 1, QImage::Format_ARGB32);
	violent_image.fill(QColor(127, 127, 255));
	violent_image_id = 0;
}


void GLRendererBase::setupLight(const Light & l, int inpass_index, int gl_index) {
	QVector3D lp = l.worldPos(), ld;// = (l.itransform_ * QVector4D(l.direction, 0.)).toVector3D().normalized();
	GLfloat pos[] = {0.f, 0.f, 0.f, 0.f};
	GLfloat dir[] = {0.f, 0.f, 0.f};
	GLfloat col[] = {0.f, 0.f, 0.f};
	pos[0] = l.light_type == Light::Directional ? -l.direction().x() : lp.x();
	pos[1] = l.light_type == Light::Directional ? -l.direction().y() : lp.y();
	pos[2] = l.light_type == Light::Directional ? -l.direction().z() : lp.z();
	pos[3] = l.light_type == Light::Directional ? 0. : 1.;
	dir[0] = ld.x();
	dir[1] = ld.y();
	dir[2] = ld.z();
	//col[0] = l.visible_ ? l.color().redF() * l.intensity : 0.f;
	//col[1] = l.visible_ ? l.color().greenF() * l.intensity : 0.f;
	//col[2] = l.visible_ ? l.color().blueF() * l.intensity : 0.f;
	glEnable(gl_index);
	//glLightfv(gl_index, GL_AMBIENT, ambient);
	glLightfv(gl_index, GL_DIFFUSE, col);
	glLightfv(gl_index, GL_SPECULAR, col);
	glLightfv(gl_index, GL_POSITION, pos);
	glLightf(gl_index, GL_CONSTANT_ATTENUATION, l.decay_const);
	glLightf(gl_index, GL_LINEAR_ATTENUATION, l.decay_linear);
	glLightf(gl_index, GL_QUADRATIC_ATTENUATION, l.decay_quadratic);
	if (l.light_type == Light::Cone) {
		glLightfv(gl_index, GL_SPOT_DIRECTION, dir);
		glLightf(gl_index, GL_SPOT_CUTOFF, l.angle_end / 2.f);
		glLightf(gl_index, GL_SPOT_EXPONENT, (1.f - piClamp<float>((l.angle_end - l.angle_start) / (l.angle_end + 0.001f), 0., 1.f)) * 128.f);
	} else {
		glLightf(gl_index, GL_SPOT_CUTOFF, 180.);
	}

}


void GLRendererBase::setupAmbientLight(const QColor & a, bool first_pass) {
	GLfloat ambient[] = {0.0f, 0.0f, 0.0f, 1.f};
	if (first_pass) {
		ambient[0] = view->ambientColor_.redF();
		ambient[1] = view->ambientColor_.greenF();
		ambient[2] = view->ambientColor_.blueF();
	}
	glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambient);
}


void GLRendererBase::setupShadersLights(int lights_count) {
	/*foreach (QOpenGLShaderProgram * i, view->shaders_ppl) {
		i->bind();
		i->setUniformValue("lightsCount", lights_count);
		i->setUniformValue("acc_light", lights_count > 0);
		//i->setUniformValue("mat", mvm);
	}*/
}


#define BIND_TEXTURE(ch, map) if (rp.prev_tex[ch] != mat.map.bitmap_id) { \
								rp.prev_tex[ch] = mat.map.bitmap_id; \
								glActiveTexture(GL_TEXTURE0 + ch); glBindTexture(GL_TEXTURE_2D, mat.map.bitmap_id); \
								glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, view->feature(QGLView::qglAnisotropicLevel).toInt());}

void GLRendererBase::setupTextures(ObjectBase & o, GLRendererBase::RenderingParameters & rp, bool first_object) {
}

#undef BIND_TEXTURE


void GLRendererBase::setupLights(int pass, int lights_per_pass) {
	/*int light_start, light_end, lmax;
	light_start = pass * lights_per_pass;
	light_end = qMin<int>((pass + 1) * lights_per_pass, view->lights_.size());
	setupAmbientLight(view->ambientColor_, pass == 0);
	if (!view->lights_.isEmpty()) {
		setupShadersLights(light_end - light_start);
		for (int i = light_start; i < light_end; ++i)
			setupLight(*view->lights_[i], i - light_start, GL_LIGHT0 + i - light_start);
		lmax = light_start + 8;
		for (int i = light_end; i < lmax; ++i)
			glDisable(GL_LIGHT0 + i - light_start);
	} else {
		setupShadersLights(0);
		for (int i = 0; i < 8; ++i)
			glDisable(GL_LIGHT0 + i);
	}*/
}


void GLRendererBase::applyFilteringParameters() {
	/*if (view->isFeatureEnabled(QGLView::qglLinearFiltering)) {
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
	} else {
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST);
	}*/
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, view->feature(QGLView::qglAnisotropicLevel).toInt());
}


void GLRendererBase::renderObjects(int pass, int light_pass, void * shaders, bool textures, bool light, bool fog) {
	/*RenderingParameters rpl;
	rpl.pass = pass;
	rpl.light_pass = light_pass;
	rpl.shaders = shaders;
	rpl.textures = textures;
	rpl.light = rpl.prev_light = light;
	rpl.fog = rpl.prev_fog = fog;
	rpl.view_matrix = rp.view_matrix;
	rpl.prev_view_matrix = rp.prev_view_matrix;
	rpl.proj_matrix = rp.proj_matrix;
	rpl.prev_proj_matrix = rp.prev_proj_matrix;
	rpl.cam_offset_matrix = view->camera()->offsetMatrix();
	//qDebug() << "view:" << rp.view_matrix;
	for (int i = 0; i < 32; ++i) rpl.prev_tex[i] = 0;
	setupTextures(view->objects_, rpl, true);
	glSetCapEnabled(GL_TEXTURE_2D, rpl.textures);
	glSetCapEnabled(GL_BLEND, pass == ObjectBase::Transparent);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	glDisable(GL_TEXTURE_CUBE_MAP);
	glPushMatrix();
	renderSingleObject(view->objects_, rpl);
	glPopMatrix();*/
}


void GLRendererBase::renderSingleObject(ObjectBase & o, RenderingParameters & rpl) {
//	if (!o.isInit())
//		o.init();
//	if (!o.isTexturesLoaded())
//		o.loadTextures();
//	if (!o.visible_) return;
//	if (rpl.pass == o.pass_) {
//		//Material & mat(o.material_);
//		QMatrix4x4 curview = rpl.view_matrix * rpl.cam_offset_matrix * o.itransform_, prevview = rpl.prev_view_matrix * rpl.cam_offset_matrix * o.itransform_;
//		//setupTextures(o, rpl, false);
//		//mat.apply((QOpenGLShaderProgram*)rpl.shaders);
//		glSetPolygonMode(o.render_mode != ObjectBase::View ? o.render_mode : (view->rmode != ObjectBase::View ? view->rmode : GL_FILL));
//		glLineWidth(o.line_width > 0.f ? o.line_width : view->lineWidth_);
//		glPointSize(o.line_width > 0.f ? o.line_width : view->lineWidth_);
//		o.update();
//		/*if (o.pass_ == GLObjectBase::Transparent) {
//			glActiveTexture(GL_TEXTURE0 + 3);
//			if (mat.reflectivity > 0.f) {
//				glEnable(GL_TEXTURE_CUBE_MAP);
//				//if (!mat.map_reflection.isEmpty()) mat.map_reflection.bind();
//				//else glDisable(GL_TEXTURE_CUBE_MAP);
//			} else glDisable(GL_TEXTURE_CUBE_MAP);
//			if (rpl.light_pass > 0) glDisable(GL_TEXTURE_CUBE_MAP);
//			GLfloat gm[16], bc[4] = {mat.reflectivity, mat.reflectivity, mat.reflectivity, mat.reflectivity};
//			glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE);
//			glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_INTERPOLATE);
//			glTexEnvi(GL_TEXTURE_ENV, GL_SRC2_RGB, GL_CONSTANT);
//			glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND2_RGB, GL_SRC_COLOR);
//			glTexEnvfv(GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR, bc);
//			glGetFloatv(GL_MODELVIEW_MATRIX, gm);
//			glMatrixMode(GL_TEXTURE);
//			///glLoadTransposeMatrixf(gm);
//			glScalef(-1., -1., -1.);
//			glMatrixMode(GL_MODELVIEW);
//			glActiveTexture(GL_TEXTURE0);
//		}*/
//		if (rpl.shaders) {
//			//qDebug() << o.name() << curview << curview->determinant();
//			//setUniformMatrices((QOpenGLShaderProgram*)rpl.shaders, rpl.proj_matrix, curview, rpl.prev_proj_matrix, prevview);
//		} else {
//			glMatrixMode(GL_MODELVIEW);
//			//setGLMatrix(curview);
//		}
//		o.draw((QOpenGLShaderProgram*)rpl.shaders);
//	}
//	foreach (ObjectBase * i, o.children_)
//		renderSingleObject(*i, rpl);
}


void GLRendererBase::renderShadow(Light * l, QOpenGLShaderProgram * prog, QMatrix4x4 mat) {
	Camera cam;
	QVector3D wp = l->worldPos();
	cam.setPos(wp);
	cam.setAim(wp + (l->worldTransform() * QVector4D(l->direction())).toVector3D());
	cam.setDepthStart(view->camera()->depthStart());
	cam.setFOV(l->angle_end);
	//cam.apply(1.);
	/*cam.rotateXY(l->angle_end);
	QVector3D rdir = l->direction * cos(l->angle_end / 2. * deg2rad);
	l->dir0 = cam.direction() - rdir;
	cam.rotateXY(-l->angle_end);
	cam.rotateZ(l->angle_end);
	l->dir1 = cam.direction() - rdir;*/
	//qDebug() << rdir << l->dir0 << l->dir1;
	RenderingParameters rpl;
	rpl.shaders = prog;
	rpl.textures = rpl.light = rpl.fog = false;
	//rpl.view_matrix = getGLMatrix(GL_MODELVIEW_MATRIX);
	//rpl.proj_matrix = getGLMatrix(GL_PROJECTION_MATRIX);
	rpl.cam_offset_matrix = cam.offsetMatrix();
	QMatrix4x4 mbias;
	mbias.scale(0.5, 0.5, 0.5);
	mbias.translate(1., 1., 1.);
	l->shadow_matrix = mbias*rpl.proj_matrix*rpl.view_matrix*rpl.cam_offset_matrix*mat;//;// * mbias;
	//qDebug() << mbias;
	//glPushMatrix();
	//renderSingleShadow(view->objects_, rpl);
	//glPopMatrix();
}


void GLRendererBase::renderSingleShadow(ObjectBase & o, RenderingParameters & rpl) {
//	if (!o.isInit())
//		o.init();
//	if (!o.visible_) return;
//	if (rpl.shaders) {
//		//qDebug() << o.name() << curview << curview->determinant();
//		//setUniformMatrices((QOpenGLShaderProgram*)rpl.shaders, rpl.proj_matrix, rpl.view_matrix * rpl.cam_offset_matrix * o.itransform_);
//	} else {
//		glMatrixMode(GL_MODELVIEW);
//		//setGLMatrix(rpl.view_matrix * rpl.cam_offset_matrix * o.itransform_);
//	}
//	glPolygonMode(GL_FRONT_AND_BACK, o.render_mode != ObjectBase::View ? o.render_mode : (view->rmode != ObjectBase::View ? view->rmode : GL_FILL));
//	glLineWidth(o.line_width > 0.f ? o.line_width : view->lineWidth_);
//	glPointSize(o.line_width > 0.f ? o.line_width : view->lineWidth_);
//	o.draw((QOpenGLShaderProgram*)rpl.shaders, true);
//	foreach (ObjectBase * i, o.children_)
//		renderSingleShadow(*i, rpl);
}




GLRendererBase::RenderingParameters::RenderingParameters() {
	shaders = nullptr;
	cur_shader = nullptr;
}


void GLRendererBase::RenderingParameters::prepare() {
	//proj_matrix = getGLMatrix(GL_PROJECTION_MATRIX);
	//view_matrix = getGLMatrix(GL_MODELVIEW_MATRIX);
	viewproj_matrix = proj_matrix * view_matrix;
	normal_matrix = view_matrix.normalMatrix();
	proj_matrix_i = proj_matrix.inverted();
	view_matrix_i = view_matrix.inverted();
	viewproj_matrix_i = viewproj_matrix.inverted();
}


void GLRendererBase::RenderingParameters::setUniform(QOpenGLShaderProgram * prog) {
	if (!prog) return;
	prog->setUniformValue("qgl_ModelViewMatrix", view_matrix);
	prog->setUniformValue("qgl_ProjectionMatrix", proj_matrix);
	prog->setUniformValue("qgl_ModelViewProjectionMatrix", viewproj_matrix);
	prog->setUniformValue("qgl_NormalMatrix", normal_matrix);
	prog->setUniformValue("qgl_ModelViewMatrixInverse", view_matrix_i);
	prog->setUniformValue("qgl_ProjectionMatrixInverse", proj_matrix_i);
	prog->setUniformValue("qgl_ModelViewProjectionMatrixInverse", viewproj_matrix_i);
	prog->setUniformValue("qgl_ModelViewMatrixTranspose", view_matrix.transposed());
	prog->setUniformValue("qgl_ProjectionMatrixTranspose", proj_matrix.transposed());
	prog->setUniformValue("qgl_ModelViewProjectionMatrixTranspose", viewproj_matrix.transposed());
	prog->setUniformValue("qgl_ModelViewMatrixInverseTranspose", view_matrix_i.transposed());
	prog->setUniformValue("qgl_ProjectionMatrixInverseTranspose", proj_matrix_i.transposed());
	prog->setUniformValue("qgl_ModelViewProjectionMatrixInverseTranspose", viewproj_matrix_i.transposed());
}