scummvm/graphics/tinygl/select.cpp
2014-08-13 18:52:52 +02:00

141 lines
3.5 KiB
C++

/* ResidualVM - A 3D game interpreter
*
* ResidualVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the AUTHORS
* file distributed with this source distribution.
*
* 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.
*
*/
/*
* This file is based on, or a modified version of code from TinyGL (C) 1997-1998 Fabrice Bellard,
* which is licensed under the zlib-license (see LICENSE).
* It also has modifications by the ResidualVM-team, which are covered under the GPLv2 (or later).
*/
#include "graphics/tinygl/zgl.h"
namespace TinyGL {
int glRenderMode(int mode) {
GLContext *c = gl_get_context();
int result = 0;
switch (c->render_mode) {
case TGL_RENDER:
break;
case TGL_SELECT:
if (c->select_overflow) {
result = -c->select_hits;
} else {
result = c->select_hits;
}
c->select_overflow = 0;
c->select_ptr = c->select_buffer;
c->name_stack_size = 0;
break;
default:
assert(0);
}
switch (mode) {
case TGL_RENDER:
c->render_mode = TGL_RENDER;
break;
case TGL_SELECT:
c->render_mode = TGL_SELECT;
assert(c->select_buffer != NULL);
c->select_ptr = c->select_buffer;
c->select_hits = 0;
c->select_overflow = 0;
c->select_hit = NULL;
break;
default:
assert(0);
}
return result;
}
void glSelectBuffer(int size, unsigned int *buf) {
GLContext *c = gl_get_context();
assert(c->render_mode != TGL_SELECT);
c->select_buffer = buf;
c->select_size = size;
}
void glopInitNames(GLContext *c, GLParam *) {
if (c->render_mode == TGL_SELECT) {
c->name_stack_size = 0;
c->select_hit = NULL;
}
}
void glopPushName(GLContext *c, GLParam *p) {
if (c->render_mode == TGL_SELECT) {
assert(c->name_stack_size < MAX_NAME_STACK_DEPTH);
c->name_stack[c->name_stack_size++] = p[1].i;
c->select_hit = NULL;
}
}
void glopPopName(GLContext *c, GLParam *) {
if (c->render_mode == TGL_SELECT) {
assert(c->name_stack_size > 0);
c->name_stack_size--;
c->select_hit = NULL;
}
}
void glopLoadName(GLContext *c, GLParam *p) {
if (c->render_mode == TGL_SELECT) {
assert(c->name_stack_size > 0);
c->name_stack[c->name_stack_size - 1] = p[1].i;
c->select_hit = NULL;
}
}
void gl_add_select(GLContext *c, unsigned int zmin, unsigned int zmax) {
unsigned int *ptr;
int n;
if (!c->select_overflow) {
if (!c->select_hit) {
n = c->name_stack_size;
if ((c->select_ptr - c->select_buffer + 3 + n) > c->select_size) {
c->select_overflow = 1;
} else {
ptr = c->select_ptr;
c->select_hit = ptr;
*ptr++ = c->name_stack_size;
*ptr++ = zmin;
*ptr++ = zmax;
for (int i = 0; i < n; i++)
*ptr++ = c->name_stack[i];
c->select_ptr = ptr;
c->select_hits++;
}
} else {
if (zmin < c->select_hit[1])
c->select_hit[1] = zmin;
if (zmax > c->select_hit[2])
c->select_hit[2] = zmax;
}
}
}
} // end of namespace TinyGL