tr_backend.c

3D 游戏界的大牛人 John Carmack 终于放出了 Q3 的源代码

#ifdef __MACOS__	// crutch up the mac's limited buffer queue size
				int		t;

				t = ri.Milliseconds();
				if ( t > macEventTime ) {
					macEventTime = t + MAC_EVENT_PUMP_MSEC;
					Sys_PumpEvents();
				}
#endif
				RB_EndSurface();
			}
			RB_BeginSurface( shader, fogNum );
			oldShader = shader;
			oldFogNum = fogNum;
			oldDlighted = dlighted;
		}

		//
		// change the modelview matrix if needed
		//
		if ( entityNum != oldEntityNum ) {
			depthRange = qfalse;

			if ( entityNum != ENTITYNUM_WORLD ) {
				backEnd.currentEntity = &backEnd.refdef.entities[entityNum];
				backEnd.refdef.floatTime = originalTime - backEnd.currentEntity->e.shaderTime;
				// we have to reset the shaderTime as well otherwise image animations start
				// from the wrong frame
				tess.shaderTime = backEnd.refdef.floatTime - tess.shader->timeOffset;

				// set up the transformation matrix
				R_RotateForEntity( backEnd.currentEntity, &backEnd.viewParms, &backEnd.or );

				// set up the dynamic lighting if needed
				if ( backEnd.currentEntity->needDlights ) {
					R_TransformDlights( backEnd.refdef.num_dlights, backEnd.refdef.dlights, &backEnd.or );
				}

				if ( backEnd.currentEntity->e.renderfx & RF_DEPTHHACK ) {
					// hack the depth range to prevent view model from poking into walls
					depthRange = qtrue;
				}
			} else {
				backEnd.currentEntity = &tr.worldEntity;
				backEnd.refdef.floatTime = originalTime;
				backEnd.or = backEnd.viewParms.world;
				// we have to reset the shaderTime as well otherwise image animations on
				// the world (like water) continue with the wrong frame
				tess.shaderTime = backEnd.refdef.floatTime - tess.shader->timeOffset;
				R_TransformDlights( backEnd.refdef.num_dlights, backEnd.refdef.dlights, &backEnd.or );
			}

			qglLoadMatrixf( backEnd.or.modelMatrix );

			//
			// change depthrange if needed
			//
			if ( oldDepthRange != depthRange ) {
				if ( depthRange ) {
					qglDepthRange (0, 0.3);
				} else {
					qglDepthRange (0, 1);
				}
				oldDepthRange = depthRange;
			}

			oldEntityNum = entityNum;
		}

		// add the triangles for this surface
		rb_surfaceTable[ *drawSurf->surface ]( drawSurf->surface );
	}

	backEnd.refdef.floatTime = originalTime;

	// draw the contents of the last shader batch
	if (oldShader != NULL) {
		RB_EndSurface();
	}

	// go back to the world modelview matrix
	qglLoadMatrixf( backEnd.viewParms.world.modelMatrix );
	if ( depthRange ) {
		qglDepthRange (0, 1);
	}

#if 0
	RB_DrawSun();
#endif
	// darken down any stencil shadows
	RB_ShadowFinish();		

	// add light flares on lights that aren't obscured
	RB_RenderFlares();

#ifdef __MACOS__
	Sys_PumpEvents();		// crutch up the mac's limited buffer queue size
#endif
}


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

RENDER BACK END THREAD FUNCTIONS

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

/*
================
RB_SetGL2D

================
*/
void	RB_SetGL2D (void) {
	backEnd.projection2D = qtrue;

	// set 2D virtual screen size
	qglViewport( 0, 0, glConfig.vidWidth, glConfig.vidHeight );
	qglScissor( 0, 0, glConfig.vidWidth, glConfig.vidHeight );
	qglMatrixMode(GL_PROJECTION);
    qglLoadIdentity ();
	qglOrtho (0, glConfig.vidWidth, glConfig.vidHeight, 0, 0, 1);
	qglMatrixMode(GL_MODELVIEW);
    qglLoadIdentity ();

	GL_State( GLS_DEPTHTEST_DISABLE |
			  GLS_SRCBLEND_SRC_ALPHA |
			  GLS_DSTBLEND_ONE_MINUS_SRC_ALPHA );

	qglDisable( GL_CULL_FACE );
	qglDisable( GL_CLIP_PLANE0 );

	// set time for 2D shaders
	backEnd.refdef.time = ri.Milliseconds();
	backEnd.refdef.floatTime = backEnd.refdef.time * 0.001f;
}


/*
=============
RE_StretchRaw

FIXME: not exactly backend
Stretches a raw 32 bit power of 2 bitmap image over the given screen rectangle.
Used for cinematics.
=============
*/
void RE_StretchRaw (int x, int y, int w, int h, int cols, int rows, const byte *data, int client, qboolean dirty) {
	int			i, j;
	int			start, end;

	if ( !tr.registered ) {
		return;
	}
	R_SyncRenderThread();

	// we definately want to sync every frame for the cinematics
	qglFinish();

	start = end = 0;
	if ( r_speeds->integer ) {
		start = ri.Milliseconds();
	}

	// make sure rows and cols are powers of 2
	for ( i = 0 ; ( 1 << i ) < cols ; i++ ) {
	}
	for ( j = 0 ; ( 1 << j ) < rows ; j++ ) {
	}
	if ( ( 1 << i ) != cols || ( 1 << j ) != rows) {
		ri.Error (ERR_DROP, "Draw_StretchRaw: size not a power of 2: %i by %i", cols, rows);
	}

	GL_Bind( tr.scratchImage[client] );

	// if the scratchImage isn't in the format we want, specify it as a new texture
	if ( cols != tr.scratchImage[client]->width || rows != tr.scratchImage[client]->height ) {
		tr.scratchImage[client]->width = tr.scratchImage[client]->uploadWidth = cols;
		tr.scratchImage[client]->height = tr.scratchImage[client]->uploadHeight = rows;
		qglTexImage2D( GL_TEXTURE_2D, 0, GL_RGB8, cols, rows, 0, GL_RGBA, GL_UNSIGNED_BYTE, data );
		qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
		qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
		qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP );
		qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP );	
	} else {
		if (dirty) {
			// otherwise, just subimage upload it so that drivers can tell we are going to be changing
			// it and don't try and do a texture compression
			qglTexSubImage2D( GL_TEXTURE_2D, 0, 0, 0, cols, rows, GL_RGBA, GL_UNSIGNED_BYTE, data );
		}
	}

	if ( r_speeds->integer ) {
		end = ri.Milliseconds();
		ri.Printf( PRINT_ALL, "qglTexSubImage2D %i, %i: %i msec\n", cols, rows, end - start );
	}

	RB_SetGL2D();

	qglColor3f( tr.identityLight, tr.identityLight, tr.identityLight );

	qglBegin (GL_QUADS);
	qglTexCoord2f ( 0.5f / cols,  0.5f / rows );
	qglVertex2f (x, y);
	qglTexCoord2f ( ( cols - 0.5f ) / cols ,  0.5f / rows );
	qglVertex2f (x+w, y);
	qglTexCoord2f ( ( cols - 0.5f ) / cols, ( rows - 0.5f ) / rows );
	qglVertex2f (x+w, y+h);
	qglTexCoord2f ( 0.5f / cols, ( rows - 0.5f ) / rows );
	qglVertex2f (x, y+h);
	qglEnd ();
}

void RE_UploadCinematic (int w, int h, int cols, int rows, const byte *data, int client, qboolean dirty) {

	GL_Bind( tr.scratchImage[client] );

	// if the scratchImage isn't in the format we want, specify it as a new texture
	if ( cols != tr.scratchImage[client]->width || rows != tr.scratchImage[client]->height ) {
		tr.scratchImage[client]->width = tr.scratchImage[client]->uploadWidth = cols;
		tr.scratchImage[client]->height = tr.scratchImage[client]->uploadHeight = rows;
		qglTexImage2D( GL_TEXTURE_2D, 0, GL_RGB8, cols, rows, 0, GL_RGBA, GL_UNSIGNED_BYTE, data );
		qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
		qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
		qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP );
		qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP );	
	} else {
		if (dirty) {
			// otherwise, just subimage upload it so that drivers can tell we are going to be changing
			// it and don't try and do a texture compression
			qglTexSubImage2D( GL_TEXTURE_2D, 0, 0, 0, cols, rows, GL_RGBA, GL_UNSIGNED_BYTE, data );
		}
	}
}


/*
=============
RB_SetColor

=============
*/
const void	*RB_SetColor( const void *data ) {
	const setColorCommand_t	*cmd;

	cmd = (const setColorCommand_t *)data;

	backEnd.color2D[0] = cmd->color[0] * 255;
	backEnd.color2D[1] = cmd->color[1] * 255;
	backEnd.color2D[2] = cmd->color[2] * 255;
	backEnd.color2D[3] = cmd->color[3] * 255;

	return (const void *)(cmd + 1);
}

/*
=============
RB_StretchPic
=============
*/
const void *RB_StretchPic ( const void *data ) {
	const stretchPicCommand_t	*cmd;
	shader_t *shader;
	int		numVerts, numIndexes;

	cmd = (const stretchPicCommand_t *)data;

	if ( !backEnd.projection2D ) {
		RB_SetGL2D();
	}

	shader = cmd->shader;
	if ( shader != tess.shader ) {
		if ( tess.numIndexes ) {
			RB_EndSurface();
		}
		backEnd.currentEntity = &backEnd.entity2D;
		RB_BeginSurface( shader, 0 );
	}

	RB_CHECKOVERFLOW( 4, 6 );
	numVerts = tess.numVertexes;
	numIndexes = tess.numIndexes;

	tess.numVertexes += 4;
	tess.numIndexes += 6;

	tess.indexes[ numIndexes ] = numVerts + 3;
	tess.indexes[ numIndexes + 1 ] = numVerts + 0;
	tess.indexes[ numIndexes + 2 ] = numVerts + 2;
	tess.indexes[ numIndexes + 3 ] = numVerts + 2;
	tess.indexes[ numIndexes + 4 ] = numVerts + 0;
	tess.indexes[ numIndexes + 5 ] = numVerts + 1;

	*(int *)tess.vertexColors[ numVerts ] =
		*(int *)tess.vertexColors[ numVerts + 1 ] =
		*(int *)tess.vertexColors[ numVerts + 2 ] =
		*(int *)tess.vertexColors[ numVerts + 3 ] = *(int *)backEnd.color2D;

	tess.xyz[ numVerts ][0] = cmd->x;
	tess.xyz[ numVerts ][1] = cmd->y;
	tess.xyz[ numVerts ][2] = 0;

	tess.texCoords[ numVerts ][0][0] = cmd->s1;
	tess.texCoords[ numVerts ][0][1] = cmd->t1;

	tess.xyz[ numVerts + 1 ][0] = cmd->x + cmd->w;
	tess.xyz[ numVerts + 1 ][1] = cmd->y;
	tess.xyz[ numVerts + 1 ][2] = 0;

	tess.texCoords[ numVerts + 1 ][0][0] = cmd->s2;
	tess.texCoords[ numVerts + 1 ][0][1] = cmd->t1;

	tess.xyz[ numVerts + 2 ][0] = cmd->x + cmd->w;
	tess.xyz[ numVerts + 2 ][1] = cmd->y + cmd->h;
	tess.xyz[ numVerts + 2 ][2] = 0;

	tess.texCoords[ numVerts + 2 ][0][0] = cmd->s2;
	tess.texCoords[ numVerts + 2 ][0][1] = cmd->t2;

	tess.xyz[ numVerts + 3 ][0] = cmd->x;
	tess.xyz[ numVerts + 3 ][1] = cmd->y + cmd->h;
	tess.xyz[ numVerts + 3 ][2] = 0;

	tess.texCoords[ numVerts + 3 ][0][0] = cmd->s1;
	tess.texCoords[ numVerts + 3 ][0][1] = cmd->t2;

	return (const void *)(cmd + 1);
}


/*
=============
RB_DrawSurfs

=============
*/
const void	*RB_DrawSurfs( const void *data ) {
	const drawSurfsCommand_t	*cmd;

	// finish any 2D drawing if needed
	if ( tess.numIndexes ) {
		RB_EndSurface();
	}

	cmd = (const drawSurfsCommand_t *)data;

	backEnd.refdef = cmd->refdef;
	backEnd.viewParms = cmd->viewParms;

	RB_RenderDrawSurfList( cmd->drawSurfs, cmd->numDrawSurfs );

	return (const void *)(cmd + 1);
}


/*
=============
RB_DrawBuffer

=============
*/
const void	*RB_DrawBuffer( const void *data ) {
	const drawBufferCommand_t	*cmd;

	cmd = (const drawBufferCommand_t *)data;

	qglDrawBuffer( cmd->buffer );

	// clear screen for debugging
	if ( r_clear->integer ) {
		qglClearColor( 1, 0, 0.5, 1 );
		qglClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
	}

	return (const void *)(cmd + 1);
}

/*
===============
RB_ShowImages

Draw all the images to the screen, on top of whatever
was there.  This is used to test for texture thrashing.

Also called by RE_EndRegistration
===============
*/
void RB_ShowImages( void ) {
	int		i;
	image_t	*image;
	float	x, y, w, h;
	int		start, end;

	if ( !backEnd.projection2D ) {
		RB_SetGL2D();
	}

	qglClear( GL_COLOR_BUFFER_BIT );

	qglFinish();

	start = ri.Milliseconds();

	for ( i=0 ; i<tr.numImages ; i++ ) {
		image = tr.images[i];

		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->integer == 2 ) {
			w *= image->uploadWidth / 512.0f;
			h *= image->uploadHeight / 512.0f;
		}

		GL_Bind( image );
		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 = ri.Milliseconds();
	ri.Printf( PRINT_ALL, "%i msec to draw all images\n", end - start );

}


/*
=============
RB_SwapBuffers

=============
*/
const void	*RB_SwapBuffers( const void *data ) {
	const swapBuffersCommand_t	*cmd;

	// finish any 2D drawing if needed
	if ( tess.numIndexes ) {
		RB_EndSurface();
	}

	// texture swapping test
	if ( r_showImages->integer ) {
		RB_ShowImages();
	}

	cmd = (const swapBuffersCommand_t *)data;

	// we measure overdraw by reading back the stencil buffer and
	// counting up the number of increments that have happened
	if ( r_measureOverdraw->integer ) {
		int i;
		long sum = 0;
		unsigned char *stencilReadback;

		stencilReadback = ri.Hunk_AllocateTempMemory( glConfig.vidWidth * glConfig.vidHeight );
		qglReadPixels( 0, 0, glConfig.vidWidth, glConfig.vidHeight, GL_STENCIL_INDEX, GL_UNSIGNED_BYTE, stencilReadback );

		for ( i = 0; i < glConfig.vidWidth * glConfig.vidHeight; i++ ) {
			sum += stencilReadback[i];
		}

		backEnd.pc.c_overDraw += sum;
		ri.Hunk_FreeTempMemory( stencilReadback );
	}


	if ( !glState.finishCalled ) {
		qglFinish();
	}

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

	GLimp_EndFrame();

	backEnd.projection2D = qfalse;

	return (const void *)(cmd + 1);
}

/*
====================
RB_ExecuteRenderCommands

This function will be called synchronously if running without
smp extensions, or asynchronously by another thread.
====================
*/
void RB_ExecuteRenderCommands( const void *data ) {
	int		t1, t2;

	t1 = ri.Milliseconds ();

	if ( !r_smp->integer || data == backEndData[0]->commands.cmds ) {
		backEnd.smpFrame = 0;
	} else {
		backEnd.smpFrame = 1;
	}

	while ( 1 ) {
		switch ( *(const int *)data ) {
		case RC_SET_COLOR:
			data = RB_SetColor( data );
			break;
		case RC_STRETCH_PIC:
			data = RB_StretchPic( data );
			break;
		case RC_DRAW_SURFS:
			data = RB_DrawSurfs( data );
			break;
		case RC_DRAW_BUFFER:
			data = RB_DrawBuffer( data );
			break;
		case RC_SWAP_BUFFERS:
			data = RB_SwapBuffers( data );
			break;
		case RC_SCREENSHOT:
			data = RB_TakeScreenshotCmd( data );
			break;

		case RC_END_OF_LIST:
		default:
			// stop rendering on this thread
			t2 = ri.Milliseconds ();
			backEnd.pc.msec = t2 - t1;
			return;
		}
	}

}


/*
================
RB_RenderThread
================
*/
void RB_RenderThread( void ) {
	const void	*data;

	// wait for either a rendering command or a quit command
	while ( 1 ) {
		// sleep until we have work to do
		data = GLimp_RendererSleep();

		if ( !data ) {
			return;	// all done, renderer is shutting down
		}

		renderThreadActive = qtrue;

		RB_ExecuteRenderCommands( data );

		renderThreadActive = qfalse;
	}
}