dhewm3/neo/renderer/tr_backend.cpp
Daniel Gibson 699779e9ca Make window alpha chan opaque on Wayland, fix #426
For some reason Wayland thought it would be clever to be the only
windowing system that (non-optionally) uses the alpha chan of the
window's default OpenGL framebuffer for window transparency.
This always caused glitches with dhewm3, as Doom3 uses that alpha-chan
for blending tricks (with GL_DST_ALPHA) - especially visible in the main
menu or when the flashlight is on.
So far the workaround has been r_waylandcompat which requests an OpenGL
context/visual without alpha chan (0 alpha bits), but that also causes
glitches.
There's an EGL extension that's supposed to fix this issue
(EGL_EXT_present_opaque), and newer SDL2 versions use it (when using
the wayland backend) - but unfortunately the Mesa implementation is
broken (seems to provide a visual without alpha channel even if one was
requested), see https://gitlab.freedesktop.org/mesa/mesa/-/issues/5886
and https://github.com/libsdl-org/SDL/pull/4306#issuecomment-1014770600
for the corresponding SDL2 discussion

To work around this issue, dhewm3 now disables the use of that EGL
extension and (optionally) makes sure the alpha channel is opaque at
the end of the frame.
This behavior is controlled with the r_fillWindowAlphaChan CVar:
If it's 1, this always is done (regardless if wayland is used or not),
if it's 0 it's not done (even on wayland),
if it's -1 (the default) it's only done if the SDL "video driver" is
  wayland (this could be easily enhanced later in case other windowing
  systems have the same issue)

r_waylandcompat has been removed (it never worked properly anyway),
so now the window always has an alpha chan
2022-02-05 16:34:34 +01:00

700 lines
17 KiB
C++

/*
===========================================================================
Doom 3 GPL Source Code
Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company.
This file is part of the Doom 3 GPL Source Code ("Doom 3 Source Code").
Doom 3 Source Code 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.
Doom 3 Source Code 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 Doom 3 Source Code. If not, see <http://www.gnu.org/licenses/>.
In addition, the Doom 3 Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 Source Code. If not, please request a copy in writing from id Software at the address below.
If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.
===========================================================================
*/
#include "sys/platform.h"
#include "renderer/tr_local.h"
static idCVar r_fillWindowAlphaChan( "r_fillWindowAlphaChan", "-1", CVAR_SYSTEM | CVAR_NOCHEAT | CVAR_ARCHIVE, "Make sure alpha channel of windows default framebuffer is completely opaque at the end of each frame. Needed at least when using Wayland.\n 1: do this, 0: don't do it, -1: let dhewm3 decide (default)" );
frameData_t *frameData;
backEndState_t backEnd;
/*
======================
RB_SetDefaultGLState
This should initialize all GL state that any part of the entire program
may touch, including the editor.
======================
*/
void RB_SetDefaultGLState( void ) {
int i;
qglClearDepth( 1.0f );
qglColor4f (1,1,1,1);
// the vertex array is always enabled
qglEnableClientState( GL_VERTEX_ARRAY );
qglEnableClientState( GL_TEXTURE_COORD_ARRAY );
qglDisableClientState( GL_COLOR_ARRAY );
//
// make sure our GL state vector is set correctly
//
memset( &backEnd.glState, 0, sizeof( backEnd.glState ) );
backEnd.glState.forceGlState = true;
qglColorMask( 1, 1, 1, 1 );
qglEnable( GL_DEPTH_TEST );
qglEnable( GL_BLEND );
qglEnable( GL_SCISSOR_TEST );
qglEnable( GL_CULL_FACE );
qglDisable( GL_LIGHTING );
qglDisable( GL_LINE_STIPPLE );
qglDisable( GL_STENCIL_TEST );
qglPolygonMode (GL_FRONT_AND_BACK, GL_FILL);
qglDepthMask( GL_TRUE );
qglDepthFunc( GL_ALWAYS );
qglCullFace( GL_FRONT_AND_BACK );
qglShadeModel( GL_SMOOTH );
if ( r_useScissor.GetBool() ) {
qglScissor( 0, 0, glConfig.vidWidth, glConfig.vidHeight );
}
for ( i = glConfig.maxTextureUnits - 1 ; i >= 0 ; i-- ) {
GL_SelectTexture( i );
// object linear texgen is our default
qglTexGenf( GL_S, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR );
qglTexGenf( GL_T, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR );
qglTexGenf( GL_R, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR );
qglTexGenf( GL_Q, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR );
GL_TexEnv( GL_MODULATE );
qglDisable( GL_TEXTURE_2D );
if ( glConfig.texture3DAvailable ) {
qglDisable( GL_TEXTURE_3D );
}
if ( glConfig.cubeMapAvailable ) {
qglDisable( GL_TEXTURE_CUBE_MAP_EXT );
}
}
}
//=============================================================================
/*
====================
GL_SelectTexture
====================
*/
void GL_SelectTexture( int unit ) {
if ( backEnd.glState.currenttmu == unit ) {
return;
}
if ( unit < 0 || (unit >= glConfig.maxTextureUnits && unit >= glConfig.maxTextureImageUnits) ) {
common->Warning( "GL_SelectTexture: unit = %i", unit );
return;
}
qglActiveTextureARB( GL_TEXTURE0_ARB + unit );
qglClientActiveTextureARB( GL_TEXTURE0_ARB + unit );
backEnd.glState.currenttmu = unit;
}
/*
====================
GL_Cull
This handles the flipping needed when the view being
rendered is a mirored view.
====================
*/
void GL_Cull( int cullType ) {
if ( backEnd.glState.faceCulling == cullType ) {
return;
}
if ( cullType == CT_TWO_SIDED ) {
qglDisable( GL_CULL_FACE );
} else {
if ( backEnd.glState.faceCulling == CT_TWO_SIDED ) {
qglEnable( GL_CULL_FACE );
}
if ( cullType == CT_BACK_SIDED ) {
if ( backEnd.viewDef->isMirror ) {
qglCullFace( GL_FRONT );
} else {
qglCullFace( GL_BACK );
}
} else {
if ( backEnd.viewDef->isMirror ) {
qglCullFace( GL_BACK );
} else {
qglCullFace( GL_FRONT );
}
}
}
backEnd.glState.faceCulling = cullType;
}
/*
====================
GL_TexEnv
====================
*/
void GL_TexEnv( int env ) {
tmu_t *tmu;
tmu = &backEnd.glState.tmu[backEnd.glState.currenttmu];
if ( env == tmu->texEnv ) {
return;
}
tmu->texEnv = env;
switch ( env ) {
case GL_COMBINE_EXT:
case GL_MODULATE:
case GL_REPLACE:
case GL_DECAL:
case GL_ADD:
qglTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, env );
break;
default:
common->Error( "GL_TexEnv: invalid env '%d' passed\n", env );
break;
}
}
/*
=================
GL_ClearStateDelta
Clears the state delta bits, so the next GL_State
will set every item
=================
*/
void GL_ClearStateDelta( void ) {
backEnd.glState.forceGlState = true;
}
/*
====================
GL_State
This routine is responsible for setting the most commonly changed state
====================
*/
void GL_State( int stateBits ) {
int diff;
if ( !r_useStateCaching.GetBool() || backEnd.glState.forceGlState ) {
// make sure everything is set all the time, so we
// can see if our delta checking is screwing up
diff = -1;
backEnd.glState.forceGlState = false;
} else {
diff = stateBits ^ backEnd.glState.glStateBits;
if ( !diff ) {
return;
}
}
//
// check depthFunc bits
//
if ( diff & ( GLS_DEPTHFUNC_EQUAL | GLS_DEPTHFUNC_LESS | GLS_DEPTHFUNC_ALWAYS ) ) {
if ( stateBits & GLS_DEPTHFUNC_EQUAL ) {
qglDepthFunc( GL_EQUAL );
} else if ( stateBits & GLS_DEPTHFUNC_ALWAYS ) {
qglDepthFunc( GL_ALWAYS );
} else {
qglDepthFunc( GL_LEQUAL );
}
}
//
// check blend bits
//
if ( diff & ( GLS_SRCBLEND_BITS | GLS_DSTBLEND_BITS ) ) {
GLenum srcFactor, dstFactor;
switch ( stateBits & GLS_SRCBLEND_BITS ) {
case GLS_SRCBLEND_ZERO:
srcFactor = GL_ZERO;
break;
case GLS_SRCBLEND_ONE:
srcFactor = GL_ONE;
break;
case GLS_SRCBLEND_DST_COLOR:
srcFactor = GL_DST_COLOR;
break;
case GLS_SRCBLEND_ONE_MINUS_DST_COLOR:
srcFactor = GL_ONE_MINUS_DST_COLOR;
break;
case GLS_SRCBLEND_SRC_ALPHA:
srcFactor = GL_SRC_ALPHA;
break;
case GLS_SRCBLEND_ONE_MINUS_SRC_ALPHA:
srcFactor = GL_ONE_MINUS_SRC_ALPHA;
break;
case GLS_SRCBLEND_DST_ALPHA:
srcFactor = GL_DST_ALPHA;
break;
case GLS_SRCBLEND_ONE_MINUS_DST_ALPHA:
srcFactor = GL_ONE_MINUS_DST_ALPHA;
break;
case GLS_SRCBLEND_ALPHA_SATURATE:
srcFactor = GL_SRC_ALPHA_SATURATE;
break;
default:
srcFactor = GL_ONE; // to get warning to shut up
common->Error( "GL_State: invalid src blend state bits\n" );
break;
}
switch ( stateBits & GLS_DSTBLEND_BITS ) {
case GLS_DSTBLEND_ZERO:
dstFactor = GL_ZERO;
break;
case GLS_DSTBLEND_ONE:
dstFactor = GL_ONE;
break;
case GLS_DSTBLEND_SRC_COLOR:
dstFactor = GL_SRC_COLOR;
break;
case GLS_DSTBLEND_ONE_MINUS_SRC_COLOR:
dstFactor = GL_ONE_MINUS_SRC_COLOR;
break;
case GLS_DSTBLEND_SRC_ALPHA:
dstFactor = GL_SRC_ALPHA;
break;
case GLS_DSTBLEND_ONE_MINUS_SRC_ALPHA:
dstFactor = GL_ONE_MINUS_SRC_ALPHA;
break;
case GLS_DSTBLEND_DST_ALPHA:
dstFactor = GL_DST_ALPHA;
break;
case GLS_DSTBLEND_ONE_MINUS_DST_ALPHA:
dstFactor = GL_ONE_MINUS_DST_ALPHA;
break;
default:
dstFactor = GL_ONE; // to get warning to shut up
common->Error( "GL_State: invalid dst blend state bits\n" );
break;
}
qglBlendFunc( srcFactor, dstFactor );
}
//
// check depthmask
//
if ( diff & GLS_DEPTHMASK ) {
if ( stateBits & GLS_DEPTHMASK ) {
qglDepthMask( GL_FALSE );
} else {
qglDepthMask( GL_TRUE );
}
}
//
// check colormask
//
if ( diff & (GLS_REDMASK|GLS_GREENMASK|GLS_BLUEMASK|GLS_ALPHAMASK) ) {
GLboolean r, g, b, a;
r = ( stateBits & GLS_REDMASK ) ? 0 : 1;
g = ( stateBits & GLS_GREENMASK ) ? 0 : 1;
b = ( stateBits & GLS_BLUEMASK ) ? 0 : 1;
a = ( stateBits & GLS_ALPHAMASK ) ? 0 : 1;
qglColorMask( r, g, b, a );
}
//
// fill/line mode
//
if ( diff & GLS_POLYMODE_LINE ) {
if ( stateBits & GLS_POLYMODE_LINE ) {
qglPolygonMode( GL_FRONT_AND_BACK, GL_LINE );
} else {
qglPolygonMode( GL_FRONT_AND_BACK, GL_FILL );
}
}
//
// alpha test
//
if ( diff & GLS_ATEST_BITS ) {
switch ( stateBits & GLS_ATEST_BITS ) {
case 0:
qglDisable( GL_ALPHA_TEST );
break;
case GLS_ATEST_EQ_255:
qglEnable( GL_ALPHA_TEST );
qglAlphaFunc( GL_EQUAL, 1 );
break;
case GLS_ATEST_LT_128:
qglEnable( GL_ALPHA_TEST );
qglAlphaFunc( GL_LESS, 0.5 );
break;
case GLS_ATEST_GE_128:
qglEnable( GL_ALPHA_TEST );
qglAlphaFunc( GL_GEQUAL, 0.5 );
break;
default:
assert( 0 );
break;
}
}
backEnd.glState.glStateBits = stateBits;
}
/*
============================================================================
RENDER BACK END THREAD FUNCTIONS
============================================================================
*/
/*
=============
RB_SetGL2D
This is not used by the normal game paths, just by some tools
=============
*/
void RB_SetGL2D( void ) {
// set 2D virtual screen size
qglViewport( 0, 0, glConfig.vidWidth, glConfig.vidHeight );
if ( r_useScissor.GetBool() ) {
qglScissor( 0, 0, glConfig.vidWidth, glConfig.vidHeight );
}
qglMatrixMode( GL_PROJECTION );
qglLoadIdentity();
qglOrtho( 0, 640, 480, 0, 0, 1 ); // always assume 640x480 virtual coordinates
qglMatrixMode( GL_MODELVIEW );
qglLoadIdentity();
GL_State( GLS_DEPTHFUNC_ALWAYS |
GLS_SRCBLEND_SRC_ALPHA |
GLS_DSTBLEND_ONE_MINUS_SRC_ALPHA );
GL_Cull( CT_TWO_SIDED );
qglDisable( GL_DEPTH_TEST );
qglDisable( GL_STENCIL_TEST );
}
/*
=============
RB_SetBuffer
=============
*/
static void RB_SetBuffer( const void *data ) {
const setBufferCommand_t *cmd;
// see which draw buffer we want to render the frame to
cmd = (const setBufferCommand_t *)data;
backEnd.frameCount = cmd->frameCount;
qglDrawBuffer( cmd->buffer );
// clear screen for debugging
// automatically enable this with several other debug tools
// that might leave unrendered portions of the screen
if ( r_clear.GetFloat() || idStr::Length( r_clear.GetString() ) != 1 || r_lockSurfaces.GetBool() || r_singleArea.GetBool() || r_showOverDraw.GetBool() ) {
float c[3];
if ( sscanf( r_clear.GetString(), "%f %f %f", &c[0], &c[1], &c[2] ) == 3 ) {
qglClearColor( c[0], c[1], c[2], 1 );
} else if ( r_clear.GetInteger() == 2 ) {
qglClearColor( 0.0f, 0.0f, 0.0f, 1.0f );
} else if ( r_showOverDraw.GetBool() ) {
qglClearColor( 1.0f, 1.0f, 1.0f, 1.0f );
} else {
qglClearColor( 0.4f, 0.0f, 0.25f, 1.0f );
}
qglClear( GL_COLOR_BUFFER_BIT );
}
}
/*
===============
RB_ShowImages
Draw all the images to the screen, on top of whatever
was there. This is used to test for texture thrashing.
===============
*/
void RB_ShowImages( void ) {
int i;
idImage *image;
float x, y, w, h;
int start, end;
RB_SetGL2D();
//qglClearColor( 0.2, 0.2, 0.2, 1 );
//qglClear( GL_COLOR_BUFFER_BIT );
qglFinish();
start = Sys_Milliseconds();
for ( i = 0 ; i < globalImages->images.Num() ; i++ ) {
image = globalImages->images[i];
if ( image->texnum == idImage::TEXTURE_NOT_LOADED && image->partialImage == NULL ) {
continue;
}
w = glConfig.vidWidth / 20;
h = glConfig.vidHeight / 15;
x = i % 20 * w;
y = i / 20 * h;
// show in proportional size in mode 2
if ( r_showImages.GetInteger() == 2 ) {
w *= image->uploadWidth / 512.0f;
h *= image->uploadHeight / 512.0f;
}
image->Bind();
qglBegin (GL_QUADS);
qglTexCoord2f( 0, 0 );
qglVertex2f( x, y );
qglTexCoord2f( 1, 0 );
qglVertex2f( x + w, y );
qglTexCoord2f( 1, 1 );
qglVertex2f( x + w, y + h );
qglTexCoord2f( 0, 1 );
qglVertex2f( x, y + h );
qglEnd();
}
qglFinish();
end = Sys_Milliseconds();
common->Printf( "%i msec to draw all images\n", end - start );
}
/*
=============
RB_SwapBuffers
=============
*/
const void RB_SwapBuffers( const void *data ) {
// texture swapping test
if ( r_showImages.GetInteger() != 0 ) {
RB_ShowImages();
}
int fillAlpha = r_fillWindowAlphaChan.GetInteger();
if ( fillAlpha == 1 || (fillAlpha == -1 && glConfig.shouldFillWindowAlpha) )
{
// make sure the whole alpha chan of the (default) framebuffer is opaque.
// at least Wayland needs this, see also the big comment in GLimp_Init()
bool blendEnabled = qglIsEnabled( GL_BLEND );
if ( !blendEnabled )
qglEnable( GL_BLEND );
// TODO: GL_DEPTH_TEST ? (should be disabled, if it needs changing at all)
bool scissorEnabled = qglIsEnabled( GL_SCISSOR_TEST );
if( scissorEnabled )
qglDisable( GL_SCISSOR_TEST );
bool tex2Denabled = qglIsEnabled( GL_TEXTURE_2D );
if( tex2Denabled )
qglDisable( GL_TEXTURE_2D );
qglDisable( GL_VERTEX_PROGRAM_ARB );
qglDisable( GL_FRAGMENT_PROGRAM_ARB );
qglBlendEquation( GL_FUNC_ADD );
qglBlendFunc( GL_ONE, GL_ONE );
// setup transform matrices so we can easily/reliably draw a fullscreen quad
qglMatrixMode( GL_MODELVIEW );
qglPushMatrix();
qglLoadIdentity();
qglMatrixMode( GL_PROJECTION );
qglPushMatrix();
qglLoadIdentity();
qglOrtho( 0, 1, 0, 1, -1, 1 );
// draw screen-sized quad with color (0.0, 0.0, 0.0, 1.0)
const float x=0, y=0, w=1, h=1;
qglColor4f( 0.0f, 0.0f, 0.0f, 1.0f );
// debug values:
//const float x = 0.1, y = 0.1, w = 0.8, h = 0.8;
//qglColor4f( 0.0f, 0.0f, 0.5f, 1.0f );
qglBegin( GL_QUADS );
qglVertex2f( x, y ); // ( 0,0 );
qglVertex2f( x, y+h ); // ( 0,1 );
qglVertex2f( x+w, y+h ); // ( 1,1 );
qglVertex2f( x+w, y ); // ( 1,0 );
qglEnd();
// restore previous transform matrix states
qglPopMatrix(); // for projection
qglMatrixMode( GL_MODELVIEW );
qglPopMatrix(); // for modelview
// restore default or previous states
qglBlendEquation( GL_FUNC_ADD );
if ( !blendEnabled )
qglDisable( GL_BLEND );
if( tex2Denabled )
qglEnable( GL_TEXTURE_2D );
if( scissorEnabled )
qglEnable( GL_SCISSOR_TEST );
}
// force a gl sync if requested
if ( r_finish.GetBool() ) {
qglFinish();
}
// don't flip if drawing to front buffer
if ( !r_frontBuffer.GetBool() ) {
GLimp_SwapBuffers();
}
}
/*
=============
RB_CopyRender
Copy part of the current framebuffer to an image
=============
*/
const void RB_CopyRender( const void *data ) {
const copyRenderCommand_t *cmd;
cmd = (const copyRenderCommand_t *)data;
if ( r_skipCopyTexture.GetBool() ) {
return;
}
if (cmd->image) {
cmd->image->CopyFramebuffer( cmd->x, cmd->y, cmd->imageWidth, cmd->imageHeight, false );
}
}
/*
====================
RB_ExecuteBackEndCommands
This function will be called syncronously if running without
smp extensions, or asyncronously by another thread.
====================
*/
int backEndStartTime, backEndFinishTime;
void RB_ExecuteBackEndCommands( const emptyCommand_t *cmds ) {
// r_debugRenderToTexture
int c_draw3d = 0, c_draw2d = 0, c_setBuffers = 0, c_swapBuffers = 0, c_copyRenders = 0;
if ( cmds->commandId == RC_NOP && !cmds->next ) {
return;
}
backEndStartTime = Sys_Milliseconds();
// needed for editor rendering
RB_SetDefaultGLState();
// upload any image loads that have completed
globalImages->CompleteBackgroundImageLoads();
for ( ; cmds ; cmds = (const emptyCommand_t *)cmds->next ) {
switch ( cmds->commandId ) {
case RC_NOP:
break;
case RC_DRAW_VIEW:
RB_DrawView( cmds );
if ( ((const drawSurfsCommand_t *)cmds)->viewDef->viewEntitys ) {
c_draw3d++;
}
else {
c_draw2d++;
}
break;
case RC_SET_BUFFER:
RB_SetBuffer( cmds );
c_setBuffers++;
break;
case RC_SWAP_BUFFERS:
RB_SwapBuffers( cmds );
c_swapBuffers++;
break;
case RC_COPY_RENDER:
RB_CopyRender( cmds );
c_copyRenders++;
break;
default:
common->Error( "RB_ExecuteBackEndCommands: bad commandId" );
break;
}
}
// go back to the default texture so the editor doesn't mess up a bound image
qglBindTexture( GL_TEXTURE_2D, 0 );
backEnd.glState.tmu[0].current2DMap = -1;
// stop rendering on this thread
backEndFinishTime = Sys_Milliseconds();
backEnd.pc.msec = backEndFinishTime - backEndStartTime;
if ( r_debugRenderToTexture.GetInteger() == 1 ) {
common->Printf( "3d: %i, 2d: %i, SetBuf: %i, SwpBuf: %i, CpyRenders: %i, CpyFrameBuf: %i\n", c_draw3d, c_draw2d, c_setBuffers, c_swapBuffers, c_copyRenders, backEnd.c_copyFrameBuffer );
backEnd.c_copyFrameBuffer = 0;
}
}