scummvm/graphics/tinygl/select.cpp
2022-03-08 15:47:20 +01:00

137 lines
3.2 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* 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 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/>.
*
*/
/*
* This file is based on, or a modified version of code from TinyGL (C) 1997-2022 Fabrice Bellard,
* which is licensed under the MIT 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 {
TGLint GLContext::gl_RenderMode(TGLenum mode) {
int result = 0;
switch (render_mode) {
case TGL_RENDER:
break;
case TGL_SELECT:
if (select_overflow) {
result = -select_hits;
} else {
result = select_hits;
}
select_overflow = 0;
select_ptr = select_buffer;
name_stack_size = 0;
break;
default:
assert(0);
}
switch (mode) {
case TGL_RENDER:
render_mode = TGL_RENDER;
break;
case TGL_SELECT:
render_mode = TGL_SELECT;
assert(select_buffer != nullptr);
select_ptr = select_buffer;
select_hits = 0;
select_overflow = 0;
select_hit = nullptr;
break;
default:
assert(0);
}
return result;
}
void GLContext::gl_SelectBuffer(TGLsizei size, TGLuint *buffer) {
assert(render_mode != TGL_SELECT);
select_buffer = buffer;
select_size = size;
}
void GLContext::glopInitNames(GLParam *) {
if (render_mode == TGL_SELECT) {
name_stack_size = 0;
select_hit = nullptr;
}
}
void GLContext::glopPushName(GLParam *p) {
if (render_mode == TGL_SELECT) {
assert(name_stack_size < MAX_NAME_STACK_DEPTH);
name_stack[name_stack_size++] = p[1].i;
select_hit = nullptr;
}
}
void GLContext::glopPopName(GLParam *) {
if (render_mode == TGL_SELECT) {
assert(name_stack_size > 0);
name_stack_size--;
select_hit = nullptr;
}
}
void GLContext::glopLoadName(GLParam *p) {
if (render_mode == TGL_SELECT) {
assert(name_stack_size > 0);
name_stack[name_stack_size - 1] = p[1].i;
select_hit = nullptr;
}
}
void GLContext::gl_add_select(uint zmin, uint zmax) {
uint *ptr;
int n;
if (!select_overflow) {
if (!select_hit) {
n = name_stack_size;
if ((select_ptr - select_buffer + 3 + n) > select_size) {
select_overflow = 1;
} else {
ptr = select_ptr;
select_hit = ptr;
*ptr++ = name_stack_size;
*ptr++ = zmin;
*ptr++ = zmax;
for (int i = 0; i < n; i++)
*ptr++ = name_stack[i];
select_ptr = ptr;
select_hits++;
}
} else {
if (zmin < select_hit[1])
select_hit[1] = zmin;
if (zmax > select_hit[2])
select_hit[2] = zmax;
}
}
}
} // end of namespace TinyGL