tr_backend.cpp

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/*
===========================================================================

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 "../idlib/precompiled.h"
#pragma hdrstop

#include "tr_local.h"


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;

        RB_LogComment( "--- R_SetDefaultGLState ---\n" );

        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 );
                }
        }
}


/*
====================
RB_LogComment
====================
*/
void RB_LogComment( const char *comment, ... ) {
   va_list marker;

        if ( !tr.logFile ) {
                return;
        }

        fprintf( tr.logFile, "// " );
        va_start( marker, comment );
        vfprintf( tr.logFile, comment, marker );
        va_end( marker );
}


//=============================================================================



/*
====================
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 );
        RB_LogComment( "glActiveTextureARB( %i );\nglClientActiveTextureARB( %i );\n", unit, 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();
        }

        // force a gl sync if requested
        if ( r_finish.GetBool() ) {
                qglFinish();
        }

    RB_LogComment( "***************** RB_SwapBuffers *****************\n\n\n" );

        // 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;
        }

    RB_LogComment( "***************** RB_CopyRender *****************\n" );

        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;
        }
}