qzdoom/src/rendering/r_sky.cpp

144 lines
4.7 KiB
C++

//-----------------------------------------------------------------------------
//
// Copyright 1993-1996 id Software
// Copyright 1994-1996 Raven Software
// Copyright 1999-2016 Randy Heit
// Copyright 2002-2016 Christoph Oelckers
//
// 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/
//
//-----------------------------------------------------------------------------
//
// DESCRIPTION:
// Sky rendering. The DOOM sky is a texture map like any
// wall, wrapping around. 1024 columns equal 360 degrees.
// The default sky map is 256 columns and repeats 4 times
// on a 320 screen.
//
//
//-----------------------------------------------------------------------------
// Needed for FRACUNIT.
#include "m_fixed.h"
#include "c_cvars.h"
#include "g_level.h"
#include "r_sky.h"
#include "r_utility.h"
#include "v_text.h"
#include "g_levellocals.h"
//
// sky mapping
//
FTextureID skyflatnum;
// [RH] Stretch sky texture if not taller than 128 pixels?
// Also now controls capped skies. 0 = normal, 1 = stretched, 2 = capped
CUSTOM_CVAR (Int, r_skymode, 2, CVAR_ARCHIVE|CVAR_NOINITCALL)
{
R_InitSkyMap ();
}
CVAR(Float, skyoffset, 0, 0) // for testing
//==========================================================================
//
// R_InitSkyMap
//
// Called whenever the view size changes.
//
//==========================================================================
void InitSkyMap(FLevelLocals *Level)
{
int skyheight;
FTexture *skytex1, *skytex2;
// Do not allow the null texture which has no bitmap and will crash.
if (Level->skytexture1.isNull())
{
Level->skytexture1 = TexMan.CheckForTexture("-noflat-", ETextureType::Any);
}
if (Level->skytexture2.isNull())
{
Level->skytexture2 = TexMan.CheckForTexture("-noflat-", ETextureType::Any);
}
skytex1 = TexMan.GetTexture(Level->skytexture1, false);
skytex2 = TexMan.GetTexture(Level->skytexture2, false);
if (skytex1 == nullptr)
return;
if ((Level->flags & LEVEL_DOUBLESKY) && skytex1->GetDisplayHeight() != skytex2->GetDisplayHeight())
{
Printf(TEXTCOLOR_BOLD "Both sky textures must be the same height." TEXTCOLOR_NORMAL "\n");
Level->flags &= ~LEVEL_DOUBLESKY;
Level->skytexture1 = Level->skytexture2;
}
// There are various combinations for sky rendering depending on how tall the sky is:
// h < 128: Unstretched and tiled, centered on horizon
// 128 <= h < 200: Can possibly be stretched. When unstretched, the baseline is
// 28 rows below the horizon so that the top of the texture
// aligns with the top of the screen when looking straight ahead.
// When stretched, it is scaled to 228 pixels with the baseline
// in the same location as an unstretched 128-tall sky, so the top
// of the texture aligns with the top of the screen when looking
// fully up.
// h == 200: Unstretched, baseline is on horizon, and top is at the top of
// the screen when looking fully up.
// h > 200: Unstretched, but the baseline is shifted down so that the top
// of the texture is at the top of the screen when looking fully up.
skyheight = skytex1->GetDisplayHeight();
Level->skystretch = (r_skymode == 1
&& skyheight >= 128 && skyheight <= 256
&& Level->IsFreelookAllowed()
&& !(Level->flags & LEVEL_FORCETILEDSKY)) ? 1 : 0;
}
void R_InitSkyMap()
{
for(auto Level : AllLevels())
{
InitSkyMap(Level);
}
}
//==========================================================================
//
// R_UpdateSky
//
// Performs sky scrolling
//
//==========================================================================
void R_UpdateSky (uint64_t mstime)
{
double ms = (double)mstime * FRACUNIT;
for(auto Level : AllLevels())
{
// Scroll the sky
Level->sky1pos = ms * Level->skyspeed1;
Level->sky2pos = ms * Level->skyspeed2;
// The hardware renderer uses a different value range and clamps it to a single rotation
Level->hw_sky1pos = (float)(fmod((double(mstime) * Level->skyspeed1), 1024.) * (90. / 256.));
Level->hw_sky2pos = (float)(fmod((double(mstime) * Level->skyspeed2), 1024.) * (90. / 256.));
}
}