nuclear@12: /*
nuclear@12: eqemu - electronic queue system emulator
nuclear@12: Copyright (C) 2014  John Tsiombikas <nuclear@member.fsf.org>,
nuclear@12:                     Eleni-Maria Stea <eleni@mutantstargoat.com>
nuclear@12: 
nuclear@12: This program is free software: you can redistribute it and/or modify
nuclear@12: it under the terms of the GNU General Public License as published by
nuclear@12: the Free Software Foundation, either version 3 of the License, or
nuclear@12: (at your option) any later version.
nuclear@12: 
nuclear@12: This program is distributed in the hope that it will be useful,
nuclear@12: but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@12: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nuclear@12: GNU General Public License for more details.
nuclear@12: 
nuclear@12: You should have received a copy of the GNU General Public License
nuclear@12: along with this program.  If not, see <http://www.gnu.org/licenses/>.
nuclear@12: */
nuclear@3: #include <stdio.h>
nuclear@3: #include <string.h>
nuclear@4: #include <math.h>
nuclear@3: #include <GL/glew.h>
nuclear@3: #include "mesh.h"
nuclear@3: 
nuclear@3: #define ALL_VALID	0xffffffff
nuclear@3: 
nuclear@3: Mesh::Mesh()
nuclear@3: {
nuclear@3: 	buf_valid = ALL_VALID;
nuclear@4: 	bsph_valid = false;
nuclear@3: 
nuclear@4: 	for(int i=0; i<NUM_MESH_ATTRIBS; i++) {
nuclear@3: 		attr[i] = 0;
nuclear@3: 		attr_size[i] = 0;
nuclear@3: 		buf_valid &= ~(1 << i);
nuclear@3: 	}
nuclear@3: 	vcount = 0;
nuclear@3: 	glGenBuffers(NUM_MESH_ATTRIBS, vbo);
nuclear@3: }
nuclear@3: 
nuclear@3: Mesh::~Mesh()
nuclear@3: {
nuclear@4: 	for(int i=0; i<NUM_MESH_ATTRIBS; i++) {
nuclear@3: 		delete [] attr[i];
nuclear@3: 	}
nuclear@3: 	glDeleteBuffers(NUM_MESH_ATTRIBS, vbo);
nuclear@3: }
nuclear@3: 
nuclear@3: float *Mesh::set_attrib(int aidx, int count, int elemsz, float *data)
nuclear@3: {
nuclear@4: 	delete [] attr[aidx];
nuclear@3: 	attr[aidx] = new float[count * elemsz];
nuclear@4: 	memcpy(attr[aidx], data, count * elemsz * sizeof *data);
nuclear@4: 	vcount = count;
nuclear@3: 	attr_size[aidx] = elemsz;
nuclear@3: 	buf_valid &= ~(1 << aidx);
nuclear@4: 
nuclear@4: 	if(aidx == MESH_ATTR_VERTEX) {
nuclear@4: 		bsph_valid = false;
nuclear@4: 	}
nuclear@4: 
nuclear@3: 	return attr[aidx];
nuclear@3: }
nuclear@3: 
nuclear@3: float *Mesh::get_attrib(int aidx)
nuclear@3: {
nuclear@3: 	buf_valid &= ~(1 << aidx);
nuclear@4: 	if(aidx == MESH_ATTR_VERTEX) {
nuclear@4: 		bsph_valid = false;
nuclear@4: 	}
nuclear@3: 	return attr[aidx];
nuclear@3: }
nuclear@3: 
nuclear@3: const float *Mesh::get_attrib(int aidx) const
nuclear@3: {
nuclear@3: 	return attr[aidx];
nuclear@3: }
nuclear@3: 
nuclear@3: void Mesh::draw() const
nuclear@3: {
nuclear@4: 	if(!vcount) return;
nuclear@4: 
nuclear@3: 	update_buffers();
nuclear@3: 
nuclear@3: 	if(!vbo[MESH_ATTR_VERTEX]) {
nuclear@3: 		fprintf(stderr, "trying to render without a vertex buffer\n");
nuclear@3: 		return;
nuclear@3: 	}
nuclear@3: 
nuclear@3: 	glBindBuffer(GL_ARRAY_BUFFER, vbo[MESH_ATTR_VERTEX]);
nuclear@3: 	glEnableClientState(GL_VERTEX_ARRAY);
nuclear@3: 	glVertexPointer(attr_size[MESH_ATTR_VERTEX], GL_FLOAT, 0, 0);
nuclear@3: 
nuclear@3: 	if(vbo[MESH_ATTR_NORMAL]) {
nuclear@3: 		glBindBuffer(GL_ARRAY_BUFFER, vbo[MESH_ATTR_NORMAL]);
nuclear@3: 		glEnableClientState(GL_NORMAL_ARRAY);
nuclear@3: 		glNormalPointer(GL_FLOAT, 0, 0);
nuclear@3: 	}
nuclear@3: 	if(vbo[MESH_ATTR_TEXCOORD]) {
nuclear@3: 		glBindBuffer(GL_ARRAY_BUFFER, vbo[MESH_ATTR_TEXCOORD]);
nuclear@3: 		glEnableClientState(GL_TEXTURE_COORD_ARRAY);
nuclear@3: 		glTexCoordPointer(attr_size[MESH_ATTR_TEXCOORD], GL_FLOAT, 0, 0);
nuclear@3: 	}
nuclear@3: 	glBindBuffer(GL_ARRAY_BUFFER, 0);
nuclear@3: 
nuclear@3: 	glDrawArrays(GL_TRIANGLES, 0, vcount);
nuclear@3: 
nuclear@3: 	glDisableClientState(GL_VERTEX_ARRAY);
nuclear@3: 	if(vbo[MESH_ATTR_NORMAL]) {
nuclear@3: 		glDisableClientState(GL_NORMAL_ARRAY);
nuclear@3: 	}
nuclear@3: 	if(vbo[MESH_ATTR_TEXCOORD]) {
nuclear@3: 		glDisableClientState(GL_TEXTURE_COORD_ARRAY);
nuclear@3: 	}
nuclear@3: }
nuclear@3: 
nuclear@4: BSphere &Mesh::get_bounds()
nuclear@4: {
nuclear@4: 	calc_bsph();
nuclear@4: 	return bsph;
nuclear@4: }
nuclear@4: 
nuclear@4: const BSphere &Mesh::get_bounds() const
nuclear@4: {
nuclear@4: 	calc_bsph();
nuclear@4: 	return bsph;
nuclear@4: }
nuclear@4: 
nuclear@3: void Mesh::update_buffers() const
nuclear@3: {
nuclear@3: 	if(buf_valid == ALL_VALID) {
nuclear@3: 		return;
nuclear@3: 	}
nuclear@3: 
nuclear@3: 	for(int i=0; i<NUM_MESH_ATTRIBS; i++) {
nuclear@3: 		if((buf_valid & (1 << i)) == 0) {
nuclear@3: 			glBindBuffer(GL_ARRAY_BUFFER, vbo[i]);
nuclear@3: 			glBufferData(GL_ARRAY_BUFFER, vcount * attr_size[i] * sizeof(float),
nuclear@3: 					attr[i], GL_STATIC_DRAW);
nuclear@3: 			buf_valid |= 1 << i;
nuclear@3: 		}
nuclear@3: 	}
nuclear@3: }
nuclear@4: 
nuclear@4: void Mesh::calc_bsph() const
nuclear@4: {
nuclear@4: 	if(bsph_valid || !vcount) {
nuclear@4: 		return;
nuclear@4: 	}
nuclear@4: 
nuclear@4: 	Vector3 center;
nuclear@4: 
nuclear@4: 	float *vptr = attr[MESH_ATTR_VERTEX];
nuclear@4: 	for(int i=0; i<vcount; i++) {
nuclear@4: 		center = center + Vector3(vptr[0], vptr[1], vptr[2]);
nuclear@4: 		vptr += 3;
nuclear@4: 	}
nuclear@4: 	center = center * (1.0f / (float)vcount);
nuclear@4: 
nuclear@4: 	float max_lensq = 0.0f;
nuclear@4: 	vptr = attr[MESH_ATTR_VERTEX];
nuclear@4: 	for(int i=0; i<vcount; i++) {
nuclear@4: 		Vector3 v = Vector3(vptr[0], vptr[1], vptr[2]) - center;
nuclear@4: 		float lensq = dot(v, v);
nuclear@4: 		if(lensq > max_lensq) {
nuclear@4: 			max_lensq = lensq;
nuclear@4: 		}
nuclear@4: 	}
nuclear@4: 
nuclear@4: 	bsph.set_center(center);
nuclear@4: 	bsph.set_radius(sqrt(max_lensq));
nuclear@4: 
nuclear@4: 	bsph_valid = true;
nuclear@4: }