C++ qglClear函数代码示例

/*
==============
RenderBumpTriangles

==============
*/
static void RenderBumpTriangles( srfTriangles_t *lowMesh, renderBump_t *rb ) {
	int		i, j;

	RB_SetGL2D();

	qglDisable( GL_CULL_FACE );

	qglColor3f( 1, 1, 1 );

	qglMatrixMode( GL_PROJECTION );
	qglLoadIdentity();
	qglOrtho( 0, 1, 1, 0, -1, 1 );
	qglDisable( GL_BLEND );
	qglMatrixMode( GL_MODELVIEW );
	qglLoadIdentity();

	qglDisable( GL_DEPTH_TEST );

	qglClearColor(1,0,0,1);
	qglClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

	qglColor3f( 1, 1, 1 );

	// create smoothed normals for the surface, which might be
	// different than the normals at the vertexes if the
	// surface uses unsmoothedNormals, which only takes the
	// normal from a single triangle.  We need properly smoothed
	// normals to make sure that the traces always go off normal
	// to the true surface.
	idVec3	*lowMeshNormals = (idVec3 *)Mem_ClearedAlloc( lowMesh->numVerts * sizeof( *lowMeshNormals ) );
	R_DeriveFacePlanes( lowMesh );
	R_CreateSilIndexes( lowMesh );	// recreate, merging the mirrored verts back together
	const idPlane *planes = lowMesh->facePlanes;
	for ( i = 0 ; i < lowMesh->numIndexes ; i += 3, planes++ ) {
		for ( j = 0 ; j < 3 ; j++ ) {
			int		index;

			index = lowMesh->silIndexes[i+j];
			lowMeshNormals[index] += (*planes).Normal();
		}
	}
	// normalize and replicate from silIndexes to all indexes
	for ( i = 0 ; i < lowMesh->numIndexes ; i++ ) {
		lowMeshNormals[lowMesh->indexes[i]] = lowMeshNormals[lowMesh->silIndexes[i]];
		lowMeshNormals[lowMesh->indexes[i]].Normalize();
	}


	// rasterize each low poly face
	for ( j = 0 ; j < lowMesh->numIndexes ; j+=3 ) {
		// pump the event loop so the window can be dragged around
		Sys_GenerateEvents();

		RasterizeTriangle( lowMesh, lowMeshNormals, j/3, rb );

		qglClearColor(1,0,0,1);
		qglClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
		qglRasterPos2f( 0, 1 );
		qglPixelZoom( glConfig.vidWidth / (float)rb->width, glConfig.vidHeight / (float)rb->height );
		qglDrawPixels( rb->width, rb->height, GL_RGBA, GL_UNSIGNED_BYTE, rb->localPic );
		qglPixelZoom( 1, 1 );
		qglFlush();
		GLimp_SwapBuffers();
	}

	Mem_Free( lowMeshNormals );
}

/*
==================
RB_ARB2_DrawInteractions
==================
*/
void RB_ARB2_DrawInteractions( void ) {
	viewLight_t		*vLight;
	const idMaterial	*lightShader;

	GL_SelectTexture( 0 );
	qglDisableClientState( GL_TEXTURE_COORD_ARRAY );

	//
	// for each light, perform adding and shadowing
	//
	for ( vLight = backEnd.viewDef->viewLights ; vLight ; vLight = vLight->next ) {
		backEnd.vLight = vLight;

		// do fogging later
		if ( vLight->lightShader->IsFogLight() ) {
			continue;
		}
		if ( vLight->lightShader->IsBlendLight() ) {
			continue;
		}

		if ( !vLight->localInteractions && !vLight->globalInteractions
			&& !vLight->translucentInteractions ) {
			continue;
		}

		lightShader = vLight->lightShader;

		// clear the stencil buffer if needed
		if ( vLight->globalShadows || vLight->localShadows ) {
			backEnd.currentScissor = vLight->scissorRect;
			if ( r_useScissor.GetBool() ) {
				qglScissor( backEnd.viewDef->viewport.x1 + backEnd.currentScissor.x1, 
					backEnd.viewDef->viewport.y1 + backEnd.currentScissor.y1,
					backEnd.currentScissor.x2 + 1 - backEnd.currentScissor.x1,
					backEnd.currentScissor.y2 + 1 - backEnd.currentScissor.y1 );
			}
			qglClear( GL_STENCIL_BUFFER_BIT );
		} else {
			// no shadows, so no need to read or write the stencil buffer
			// we might in theory want to use GL_ALWAYS instead of disabling
			// completely, to satisfy the invarience rules
			qglStencilFunc( GL_ALWAYS, 128, 255 );
		}

		if ( r_useShadowVertexProgram.GetBool() ) {
			qglEnable( GL_VERTEX_PROGRAM_ARB );
			qglBindProgramARB( GL_VERTEX_PROGRAM_ARB, VPROG_STENCIL_SHADOW );
			RB_StencilShadowPass( vLight->globalShadows );
			RB_ARB2_CreateDrawInteractions( vLight->localInteractions );
			qglEnable( GL_VERTEX_PROGRAM_ARB );
			qglBindProgramARB( GL_VERTEX_PROGRAM_ARB, VPROG_STENCIL_SHADOW );
			RB_StencilShadowPass( vLight->localShadows );
			RB_ARB2_CreateDrawInteractions( vLight->globalInteractions );
			qglDisable( GL_VERTEX_PROGRAM_ARB );	// if there weren't any globalInteractions, it would have stayed on
		} else {
			RB_StencilShadowPass( vLight->globalShadows );
			RB_ARB2_CreateDrawInteractions( vLight->localInteractions );
			RB_StencilShadowPass( vLight->localShadows );
			RB_ARB2_CreateDrawInteractions( vLight->globalInteractions );
		}

		// translucent surfaces never get stencil shadowed
		if ( r_skipTranslucent.GetBool() ) {
			continue;
		}

		qglStencilFunc( GL_ALWAYS, 128, 255 );

		backEnd.depthFunc = GLS_DEPTHFUNC_LESS;
		RB_ARB2_CreateDrawInteractions( vLight->translucentInteractions );

		backEnd.depthFunc = GLS_DEPTHFUNC_EQUAL;
	}

	// disable stencil shadow test
	qglStencilFunc( GL_ALWAYS, 128, 255 );

	GL_SelectTexture( 0 );
	qglEnableClientState( GL_TEXTURE_COORD_ARRAY );
}

void idGLDrawableMaterial::draw(int x, int y, int w, int h) {
    const idMaterial *mat = material;
    if (mat) {
        qglViewport(x, y, w, h);
        qglScissor(x, y, w, h);
        qglMatrixMode(GL_PROJECTION);
        qglClearColor( 0.1f, 0.1f, 0.1f, 0.0f );
        qglClear(GL_COLOR_BUFFER_BIT);

        if (worldDirty) {
            InitWorld();
            renderLight_t	parms;
            idDict spawnArgs;
            spawnArgs.Set("classname", "light");
            spawnArgs.Set("name", "light_1");
            spawnArgs.Set("origin", "0 0 0");
            idStr str;
            sprintf(str, "%f %f %f", light, light, light);
            spawnArgs.Set("_color", str);
            gameEdit->ParseSpawnArgsToRenderLight( &spawnArgs, &parms );
            lightDef = world->AddLightDef( &parms );

            idImage *img = (mat->GetNumStages() > 0) ? mat->GetStage(0)->texture.image : mat->GetEditorImage();

            if (img == NULL) {
                common->Warning("Unable to load image for preview for %s", mat->GetName());
                return;
            }

            int width = img->uploadWidth;
            int height = img->uploadHeight;

            width *= scale;
            height *= scale;

            srfTriangles_t *tris = worldModel->AllocSurfaceTriangles( 4, 6 );
            tris->numVerts = 4;
            tris->numIndexes = 6;

            tris->indexes[0] = 0;
            tris->indexes[1] = 1;
            tris->indexes[2] = 2;
            tris->indexes[3] = 3;
            tris->indexes[4] = 1;
            tris->indexes[5] = 0;

            tris->verts[0].xyz.x = 64;
            tris->verts[0].xyz.y = -xOffset + 0 - width / 2;
            tris->verts[0].xyz.z = yOffset + 0 - height / 2;
            tris->verts[0].st.x = 1;
            tris->verts[0].st.y = 1;

            tris->verts[1].xyz.x = 64;
            tris->verts[1].xyz.y = -xOffset + width / 2;
            tris->verts[1].xyz.z = yOffset + height / 2;
            tris->verts[1].st.x = 0;
            tris->verts[1].st.y = 0;

            tris->verts[2].xyz.x = 64;
            tris->verts[2].xyz.y = -xOffset + 0 - width / 2;
            tris->verts[2].xyz.z = yOffset + height / 2;
            tris->verts[2].st.x = 1;
            tris->verts[2].st.y = 0;

            tris->verts[3].xyz.x = 64;
            tris->verts[3].xyz.y = -xOffset + width / 2;
            tris->verts[3].xyz.z = yOffset + 0 - height / 2;
            tris->verts[3].st.x = 0;
            tris->verts[3].st.y = 1;

            tris->verts[0].normal = tris->verts[1].xyz.Cross(tris->verts[3].xyz);
            tris->verts[1].normal = tris->verts[2].normal = tris->verts[3].normal = tris->verts[0].normal;
            AddTris(tris, mat);

            worldModel->FinishSurfaces();

            renderEntity_t worldEntity;

            memset( &worldEntity, 0, sizeof( worldEntity ) );
            if ( mat->HasGui() ) {
                worldEntity.gui[ 0 ] = mat->GlobalGui();
            }
            worldEntity.hModel = worldModel;
            worldEntity.axis = mat3_default;
            worldEntity.shaderParms[0] = 1;
            worldEntity.shaderParms[1] = 1;
            worldEntity.shaderParms[2] = 1;
            worldEntity.shaderParms[3] = 1;
            modelDef = world->AddEntityDef( &worldEntity );

            worldDirty = false;
        }

        renderView_t	refdef;
        // render it
        renderSystem->BeginFrame(w, h);
        memset( &refdef, 0, sizeof( refdef ) );
        refdef.vieworg.Set(viewAngle, 0, 0);

        refdef.viewaxis = idAngles(0,0,0).ToMat3();
//.........这里部分代码省略.........

//.........这里部分代码省略.........
					qglEndQueryARB(GL_SAMPLES_PASSED_ARB);
				}
				FBO_Bind(fbo);
				qglDepthRange(depth[0], depth[1]);
			}
#endif

			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);
				}

#ifdef REACTION
				/* if the current entity is a sunflare */
				if(backEnd.currentEntity->e.renderfx & RF_SUNFLARE){
					/* if we're rendering to a fbo */
					if(fbo){
						copyv3(backEnd.currentEntity->e.origin,
							backEnd.sunFlarePos);
						/* switch FBO */
						FBO_Bind(tr.godRaysFbo);

						qglClearColor(0.0f, 0.0f, 0.0f, 1.0f);
						qglClear(GL_COLOR_BUFFER_BIT);

						qglDepthRange(1.f, 1.f);
						if(glRefConfig.occlusionQuery && !inQuery &&
						   !backEnd.hasSunFlare){
							inQuery = qtrue;
							tr.sunFlareQueryActive[tr.sunFlareQueryIndex] = qtrue;
							qglBeginQueryARB(
								GL_SAMPLES_PASSED_ARB,
								tr.sunFlareQuery[tr.sunFlareQueryIndex]);
						}
						/* backEnd.hasSunFlare = qtrue; */
						sunflare = qtrue;
					}else{
						depthRange = qtrue;
					}
				}
#endif

				if(backEnd.currentEntity->e.renderfx & RF_DEPTHHACK){
					/* hack the depth range to prevent view model from poking into walls */
					depthRange = qtrue;

					if(backEnd.currentEntity->e.renderfx & RF_CROSSHAIR)
						isCrosshair = 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 */

/*
=================
RB_BeginDrawingView

Any mirrored or portaled views have already been drawn, so prepare
to actually render the visible surfaces for this view
=================
*/
void RB_BeginDrawingView (void) {
	int clearBits = 0;

	// sync with gl if needed
	if ( r_finish->integer == 1 && !glState.finishCalled ) {
		qglFinish ();
		glState.finishCalled = qtrue;
	}
	if ( r_finish->integer == 0 ) {
		glState.finishCalled = qtrue;
	}

	// we will need to change the projection matrix before drawing
	// 2D images again
	backEnd.projection2D = qfalse;

	//
	// set the modelview matrix for the viewer
	//
	SetViewportAndScissor();

	// ensures that depth writes are enabled for the depth clear
	GL_State( GLS_DEFAULT );
	// clear relevant buffers
	clearBits = GL_DEPTH_BUFFER_BIT;

	if ( r_measureOverdraw->integer || r_shadows->integer == 2 )
	{
		clearBits |= GL_STENCIL_BUFFER_BIT;
	}
	if ( r_fastsky->integer && !( backEnd.refdef.rdflags & RDF_NOWORLDMODEL ) )
	{
		clearBits |= GL_COLOR_BUFFER_BIT;	// FIXME: only if sky shaders have been used
		qglClearColor( 0.8f, 0.7f, 0.4f, 1 );	// FIXME: get color of sky
	}
	qglClear( clearBits );

	if ( ( backEnd.refdef.rdflags & RDF_HYPERSPACE ) )
	{
		RB_Hyperspace();
		return;
	}
	else
	{
		backEnd.isHyperspace = qfalse;
	}

	glState.faceCulling = -1;		// force face culling to set next time

	// we will only draw a sun if there was sky rendered in this view
	backEnd.skyRenderedThisView = qfalse;

	// clip to the plane of the portal
	if ( backEnd.viewParms.isPortal ) {
		float	plane[4];
		double	plane2[4];

		plane[0] = backEnd.viewParms.portalPlane.normal[0];
		plane[1] = backEnd.viewParms.portalPlane.normal[1];
		plane[2] = backEnd.viewParms.portalPlane.normal[2];
		plane[3] = backEnd.viewParms.portalPlane.dist;

		plane2[0] = DotProduct (backEnd.viewParms.or.axis[0], plane);
		plane2[1] = DotProduct (backEnd.viewParms.or.axis[1], plane);
		plane2[2] = DotProduct (backEnd.viewParms.or.axis[2], plane);
		plane2[3] = DotProduct (plane, backEnd.viewParms.or.origin) - plane[3];

		qglLoadMatrixf( s_flipMatrix );
		qglClipPlane (GL_CLIP_PLANE0, plane2);
		qglEnable (GL_CLIP_PLANE0);
	} else {
		qglDisable (GL_CLIP_PLANE0);
	}
}

/*
================
RB_StageIteratorSky

All of the visible sky triangles are in tess

Other things could be stuck in here, like birds in the sky, etc
================
*/
void RB_StageIteratorSky( void ) {
	int clearBits = 0;

	if ( r_fastsky->integer ) {
		if (r_fastsky->integer == 2  &&  !(backEnd.refdef.rdflags & RDF_NOWORLDMODEL)) {
			clearBits |= GL_COLOR_BUFFER_BIT;	// FIXME: only if sky shaders have been used
			if (*r_fastSkyColor->string) {
				int v, tr, tg, tb;

				v = r_fastSkyColor->integer;
				tr = (v & 0xff0000) / 0x010000;
				tg = (v & 0x00ff00) / 0x000100;
				tb = (v & 0x0000ff) / 0x000001;

				qglClearColor((float)tr / 255.0, (float)tg / 255.0, (float)tb / 255.0, 1.0);
			} else {
				qglClearColor(0.0f, 0.0f, 0.0f, 1.0f);	// FIXME: get color of sky
			}

			qglClear(clearBits);
		}

		return;
	}

	// go through all the polygons and project them onto
	// the sky box to see which blocks on each side need
	// to be drawn
	RB_ClipSkyPolygons( &tess );

	// r_showsky will let all the sky blocks be drawn in
	// front of everything to allow developers to see how
	// much sky is getting sucked in
	if ( r_showsky->integer ) {
		qglDepthRange( 0.0, 0.0 );
	} else {
		qglDepthRange( 1.0, 1.0 );
	}

	// draw the outer skybox
	if ( tess.shader->sky.outerbox[0] && tess.shader->sky.outerbox[0] != tr.defaultImage ) {
		qglColor3f( tr.identityLight, tr.identityLight, tr.identityLight );

		qglPushMatrix ();
		GL_State( 0 );
		GL_Cull( CT_FRONT_SIDED );
		qglTranslatef (backEnd.viewParms.or.origin[0], backEnd.viewParms.or.origin[1], backEnd.viewParms.or.origin[2]);

		DrawSkyBox( tess.shader );

		qglPopMatrix();
	}

	// generate the vertexes for all the clouds, which will be drawn
	// by the generic shader routine
	R_BuildCloudData( &tess );

	if (tess.numVertexes) {
		// yes, sky has cloud stages
		RB_StageIteratorGeneric();
	}

	// draw the inner skybox

	//FIXME not even done

	// back to normal depth range
	qglDepthRange( 0.0, 1.0 );

	// note that sky was drawn so we will draw a sun later
	backEnd.skyRenderedThisView = qtrue;
}

/*
==============
Z_Draw
==============
*/
void Z_Draw (void)
{
#ifdef DBG_WINDOWPOS
  CheckWatchit ("Z_Draw");
#endif
  brush_t	*brush;
	float	w, h;
	double	start, end;
	qtexture_t	*q;
	float	top, bottom;
	vec3_t	org_top, org_bottom, dir_up, dir_down;
	int xCam = z.width/3;

	if (!active_brushes.next)
		return;	// not valid yet

	if (z.timing)
		start = Sys_DoubleTime ();

	//
	// clear
	//
	qglViewport(0, 0, z.width, z.height);

	qglClearColor (
		g_qeglobals.d_savedinfo.colors[COLOR_GRIDBACK][0],
		g_qeglobals.d_savedinfo.colors[COLOR_GRIDBACK][1],
		g_qeglobals.d_savedinfo.colors[COLOR_GRIDBACK][2],
		0);

    /* GL Bug */ 
	/* When not using hw acceleration, gl will fault if we clear the depth 
	buffer bit on the first pass. The hack fix is to set the GL_DEPTH_BUFFER_BIT
	only after Z_Draw() has been called once. Yeah, right. */
	qglClear(glbitClear); 
	glbitClear |= GL_DEPTH_BUFFER_BIT;
	qglMatrixMode(GL_PROJECTION);

  qglLoadIdentity ();
	w = z.width/2 / z.scale;
	h = z.height/2 / z.scale;
	qglOrtho (-w, w, z.origin[2]-h, z.origin[2]+h, -8, 8);

	qglDisable(GL_TEXTURE_2D);
	qglDisable(GL_TEXTURE_1D);
	qglDisable(GL_DEPTH_TEST);
	qglDisable(GL_BLEND);


	//
	// now draw the grid
	//
	Z_DrawGrid ();

	//
	// draw stuff
	//

	qglDisable(GL_CULL_FACE);

	qglShadeModel (GL_FLAT);

	qglPolygonMode (GL_FRONT_AND_BACK, GL_FILL);

	qglDisable(GL_TEXTURE_2D);
	qglDisable(GL_BLEND);
	qglDisable(GL_DEPTH_TEST);


	// draw filled interiors and edges
	dir_up[0] = 0 ; dir_up[1] = 0; dir_up[2] = 1;
	dir_down[0] = 0 ; dir_down[1] = 0; dir_down[2] = -1;
	VectorCopy (z.origin, org_top);
	org_top[2] = g_MaxWorldCoord;
	VectorCopy (z.origin, org_bottom);
	org_bottom[2] = g_MinWorldCoord;

	for (brush = active_brushes.next ; brush != &active_brushes ; brush=brush->next)
	{
		if (brush->bFiltered)
			continue;

		if (brush->mins[0] >= z.origin[0]
			|| brush->maxs[0] <= z.origin[0]
			|| brush->mins[1] >= z.origin[1]
			|| brush->maxs[1] <= z.origin[1])
			continue;

		if (!Brush_Ray (org_top, dir_down, brush, &top))
			continue;
		top = org_top[2] - top;
		if (!Brush_Ray (org_bottom, dir_up, brush, &bottom))
			continue;
		bottom = org_bottom[2] + bottom;

//.........这里部分代码省略.........

/*
=============
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 );

	// Dynamic Glow/Flares:
	/*
		The basic idea is to render the glowing parts of the scene to an offscreen buffer, then take
		that buffer and blur it. After it is sufficiently blurred, re-apply that image back to
		the normal screen using a additive blending. To blur the scene I use a vertex program to supply
		four texture coordinate offsets that allow 'peeking' into adjacent pixels. In the register
		combiner (pixel shader), I combine the adjacent pixels using a weighting factor. - Aurelio
	*/

	// Render dynamic glowing/flaring objects.
	if ( !(backEnd.refdef.rdflags & RDF_NOWORLDMODEL) && g_bDynamicGlowSupported && r_DynamicGlow->integer )
	{
		// Copy the normal scene to texture.
		qglDisable( GL_TEXTURE_2D );
		qglEnable( GL_TEXTURE_RECTANGLE_EXT ); 
		qglBindTexture( GL_TEXTURE_RECTANGLE_EXT, tr.sceneImage ); 
		qglCopyTexSubImage2D( GL_TEXTURE_RECTANGLE_EXT, 0, 0, 0, backEnd.viewParms.viewportX, backEnd.viewParms.viewportY, backEnd.viewParms.viewportWidth, backEnd.viewParms.viewportHeight); 
		qglDisable( GL_TEXTURE_RECTANGLE_EXT );
		qglEnable( GL_TEXTURE_2D );    

		// Just clear colors, but leave the depth buffer intact so we can 'share' it.
		qglClearColor( 0.0f, 0.0f, 0.0f, 0.0f );
		qglClear( GL_COLOR_BUFFER_BIT ); 

		// Render the glowing objects.
		g_bRenderGlowingObjects = true;
		RB_RenderDrawSurfList( cmd->drawSurfs, cmd->numDrawSurfs );  
		g_bRenderGlowingObjects = false;
		qglFinish();

		// Copy the glow scene to texture.
		qglDisable( GL_TEXTURE_2D );
		qglEnable( GL_TEXTURE_RECTANGLE_EXT ); 
		qglBindTexture( GL_TEXTURE_RECTANGLE_EXT, tr.screenGlow ); 
		qglCopyTexSubImage2D( GL_TEXTURE_RECTANGLE_EXT, 0, 0, 0,  backEnd.viewParms.viewportX, backEnd.viewParms.viewportY, backEnd.viewParms.viewportWidth, backEnd.viewParms.viewportHeight ); 
		qglDisable( GL_TEXTURE_RECTANGLE_EXT );
		qglEnable( GL_TEXTURE_2D );
		
		// Resize the viewport to the blur texture size.
		const int oldViewWidth = backEnd.viewParms.viewportWidth;
		const int oldViewHeight = backEnd.viewParms.viewportHeight;
		backEnd.viewParms.viewportWidth = r_DynamicGlowWidth->integer;
		backEnd.viewParms.viewportHeight = r_DynamicGlowHeight->integer;
		SetViewportAndScissor();

		// Blur the scene.
		RB_BlurGlowTexture();

		// Copy the finished glow scene back to texture.
		qglDisable( GL_TEXTURE_2D );
		qglEnable( GL_TEXTURE_RECTANGLE_EXT );
		qglBindTexture( GL_TEXTURE_RECTANGLE_EXT, tr.blurImage );
		qglCopyTexSubImage2D( GL_TEXTURE_RECTANGLE_EXT, 0, 0, 0, 0, 0, backEnd.viewParms.viewportWidth, backEnd.viewParms.viewportHeight ); 
		qglDisable( GL_TEXTURE_RECTANGLE_EXT );
		qglEnable( GL_TEXTURE_2D );
		
		// Set the viewport back to normal.
		backEnd.viewParms.viewportWidth = oldViewWidth;
		backEnd.viewParms.viewportHeight = oldViewHeight;
		SetViewportAndScissor();
		qglClear( GL_COLOR_BUFFER_BIT ); 

		// Draw the glow additively over the screen.
		RB_DrawGlowOverlay(); 
	}

	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 (!( backEnd.refdef.rdflags & RDF_NOWORLDMODEL ) && tr.world && tr.refdef.rdflags & RDF_doLAGoggles)
	{
		const fog_t		*fog = &tr.world->fogs[tr.world->numfogs];

		qglClearColor(fog->parms.color[0],  fog->parms.color[1], fog->parms.color[2], 1.0f );
		qglClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	}
	else if (!( backEnd.refdef.rdflags & RDF_NOWORLDMODEL ) && tr.world && tr.world->globalFog != -1 && tr.sceneCount)//don't clear during menus, wait for real scene
	{
		const fog_t		*fog = &tr.world->fogs[tr.world->globalFog];

		qglClearColor(fog->parms.color[0],  fog->parms.color[1], fog->parms.color[2], 1.0f );
		qglClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
	}
	else if ( r_clear->integer ) 
	{	// clear screen for debugging
		int i = r_clear->integer;
		if (i == 42) {
			i = Q_irand(0,8);
		}
		switch (i)
		{
		default:
			qglClearColor( 1, 0, 0.5, 1 );
			break;
		case 1:
			qglClearColor( 1.0, 0.0, 0.0, 1.0); //red
			break;
		case 2:
			qglClearColor( 0.0, 1.0, 0.0, 1.0); //green
			break;
		case 3:
			qglClearColor( 1.0, 1.0, 0.0, 1.0); //yellow
			break;
		case 4:
			qglClearColor( 0.0, 0.0, 1.0, 1.0); //blue
			break;
		case 5:
			qglClearColor( 0.0, 1.0, 1.0, 1.0); //cyan
			break;
		case 6:
			qglClearColor( 1.0, 0.0, 1.0, 1.0); //magenta
			break;
		case 7:
			qglClearColor( 1.0, 1.0, 1.0, 1.0); //white
			break;
		case 8:
			qglClearColor( 0.0, 0.0, 0.0, 1.0); //black
			break;
		}		
		qglClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
	}

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

/*
====================
RE_BeginFrame

If running in stereo, RE_BeginFrame will be called twice
for each RE_EndFrame
====================
*/
void RE_BeginFrame(stereoFrame_t stereoFrame)
{
	drawBufferCommand_t *cmd    = NULL;
	colorMaskCommand_t  *colcmd = NULL;

	if (!tr.registered)
	{
		return;
	}
	glState.finishCalled = qfalse;

	tr.frameCount++;
	tr.frameSceneNum = 0;

	//
	// do overdraw measurement
	//
	if (r_measureOverdraw->integer)
	{
		if (glConfig.stencilBits < 4)
		{
			ri.Printf(PRINT_ALL, "Warning: not enough stencil bits to measure overdraw: %d\n", glConfig.stencilBits);
			ri.Cvar_Set("r_measureOverdraw", "0");
			r_measureOverdraw->modified = qfalse;
		}
		else if (r_shadows->integer == 2)
		{
			ri.Printf(PRINT_ALL, "Warning: stencil shadows and overdraw measurement are mutually exclusive\n");
			ri.Cvar_Set("r_measureOverdraw", "0");
			r_measureOverdraw->modified = qfalse;
		}
		else
		{
			R_IssuePendingRenderCommands();
			qglEnable(GL_STENCIL_TEST);
			qglStencilMask(~0U);
			qglClearStencil(0U);
			qglStencilFunc(GL_ALWAYS, 0U, ~0U);
			qglStencilOp(GL_KEEP, GL_INCR, GL_INCR);
		}
		r_measureOverdraw->modified = qfalse;
	}
	else
	{
		// this is only reached if it was on and is now off
		if (r_measureOverdraw->modified)
		{
			R_IssuePendingRenderCommands();
			qglDisable(GL_STENCIL_TEST);
		}
		r_measureOverdraw->modified = qfalse;
	}

	//
	// texturemode stuff
	//
	if (r_textureMode->modified)
	{
		R_IssuePendingRenderCommands();
		GL_TextureMode(r_textureMode->string);
		r_textureMode->modified = qfalse;
	}

	//
	// NVidia stuff
	//

	// fog control
	if (glConfig.NVFogAvailable && r_nv_fogdist_mode->modified)
	{
		r_nv_fogdist_mode->modified = qfalse;
		if (!Q_stricmp(r_nv_fogdist_mode->string, "GL_EYE_PLANE_ABSOLUTE_NV"))
		{
			glConfig.NVFogMode = (int)GL_EYE_PLANE_ABSOLUTE_NV;
		}
		else if (!Q_stricmp(r_nv_fogdist_mode->string, "GL_EYE_PLANE"))
		{
			glConfig.NVFogMode = (int)GL_EYE_PLANE;
		}
		else if (!Q_stricmp(r_nv_fogdist_mode->string, "GL_EYE_RADIAL_NV"))
		{
			glConfig.NVFogMode = (int)GL_EYE_RADIAL_NV;
		}
		else
		{
			// in case this was really 'else', store a valid value for next time
			glConfig.NVFogMode = (int)GL_EYE_RADIAL_NV;
			ri.Cvar_Set("r_nv_fogdist_mode", "GL_EYE_RADIAL_NV");
		}
	}

	//
//.........这里部分代码省略.........

/*
===============
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 / 40;
		h = glConfig.vidHeight / 30;

		x = i % 40 * w;
		y = i / 30 * h;

		// show in proportional size in mode 2
		if ( r_showImages->integer == 2 ) {
			w *= image->uploadWidth / 512.0f;
			h *= image->uploadHeight / 512.0f;
		}

#ifdef USE_OPENGLES
		GLfloat tex[] = {
		 0, 0, 
		 1, 0,
		 1, 1, 
		 0, 1 };
		GLfloat vtx[] = {
		 x, y,
		 x + w, y,
		 x + w, y + h,
		 x, y + h };
		GLboolean text = qglIsEnabled(GL_TEXTURE_COORD_ARRAY);
		GLboolean glcol = qglIsEnabled(GL_COLOR_ARRAY);
		if (glcol)
			qglDisableClientState(GL_COLOR_ARRAY);
		if (!text)
			qglEnableClientState( GL_TEXTURE_COORD_ARRAY );
		qglTexCoordPointer( 2, GL_FLOAT, 0, tex );
		qglVertexPointer  ( 2, GL_FLOAT, 0, vtx );
		qglDrawArrays( GL_TRIANGLE_FAN, 0, 4 );
		if (glcol)
			qglEnableClientState(GL_COLOR_ARRAY);
		if (!text)
			qglDisableClientState( GL_TEXTURE_COORD_ARRAY );
#else
		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();
#endif
	}

	qglFinish();

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

}

/*
=================
RB_BeginDrawingView

Any mirrored or portaled views have already been drawn, so prepare
to actually render the visible surfaces for this view
=================
*/
void RB_BeginDrawingView (void) {
	int clearBits = 0;

	// sync with gl if needed
	if ( r_finish->integer == 1 && !glState.finishCalled ) {
		qglFinish ();
		glState.finishCalled = qtrue;
	}
	if ( r_finish->integer == 0 ) {
		glState.finishCalled = qtrue;
	}

	// we will need to change the projection matrix before drawing
	// 2D images again
	backEnd.projection2D = qfalse;

	if (glRefConfig.framebufferObject)
	{
		FBO_t *fbo = backEnd.viewParms.targetFbo;

		// FIXME: HUGE HACK: render to the screen fbo if we've already postprocessed the frame and aren't drawing more world
		// drawing more world check is in case of double renders, such as skyportals
		if (fbo == NULL && !(backEnd.framePostProcessed && (backEnd.refdef.rdflags & RDF_NOWORLDMODEL)))
			fbo = tr.renderFbo;

		if (tr.renderCubeFbo && fbo == tr.renderCubeFbo)
		{
			cubemap_t *cubemap = &tr.cubemaps[backEnd.viewParms.targetFboCubemapIndex];
			FBO_AttachImage(fbo, cubemap->image, GL_COLOR_ATTACHMENT0_EXT, backEnd.viewParms.targetFboLayer);
		}

		FBO_Bind(fbo);
	}

	//
	// set the modelview matrix for the viewer
	//
	SetViewportAndScissor();

	// ensures that depth writes are enabled for the depth clear
	GL_State( GLS_DEFAULT );
	// clear relevant buffers
	clearBits = GL_DEPTH_BUFFER_BIT;

	if ( r_measureOverdraw->integer || r_shadows->integer == 2 )
	{
		clearBits |= GL_STENCIL_BUFFER_BIT;
	}
	if ( r_fastsky->integer && !( backEnd.refdef.rdflags & RDF_NOWORLDMODEL ) )
	{
		clearBits |= GL_COLOR_BUFFER_BIT;	// FIXME: only if sky shaders have been used
	}

	// clear to black for cube maps
	if (tr.renderCubeFbo && backEnd.viewParms.targetFbo == tr.renderCubeFbo)
	{
		clearBits |= GL_COLOR_BUFFER_BIT;
	}

	qglClear( clearBits );

	if ( ( backEnd.refdef.rdflags & RDF_HYPERSPACE ) )
	{
		RB_Hyperspace();
		return;
	}
	else
	{
		backEnd.isHyperspace = qfalse;
	}

	// we will only draw a sun if there was sky rendered in this view
	backEnd.skyRenderedThisView = qfalse;

	// clip to the plane of the portal
	if ( backEnd.viewParms.isPortal ) {
#if 0
		float	plane[4];
		GLdouble	plane2[4];

		plane[0] = backEnd.viewParms.portalPlane.normal[0];
		plane[1] = backEnd.viewParms.portalPlane.normal[1];
		plane[2] = backEnd.viewParms.portalPlane.normal[2];
		plane[3] = backEnd.viewParms.portalPlane.dist;

		plane2[0] = DotProduct (backEnd.viewParms.or.axis[0], plane);
		plane2[1] = DotProduct (backEnd.viewParms.or.axis[1], plane);
		plane2[2] = DotProduct (backEnd.viewParms.or.axis[2], plane);
		plane2[3] = DotProduct (plane, backEnd.viewParms.or.origin) - plane[3];
#endif
		GL_SetModelviewMatrix( s_flipMatrix );
	}
//.........这里部分代码省略.........

/*
 ==================
 GL_Setup3D

 TODO: time is messed up
 ==================
*/
void GL_Setup3D (int time){

	double	clipPlane[4];

	QGL_LogPrintf("---------- RB_Setup3D ----------\n");

	backEnd.projection2D = false;

	backEnd.time = time;
	backEnd.floatTime = MS2SEC(Sys_Milliseconds());

	backEnd.viewport.x = backEnd.viewParms.viewport.x;
	backEnd.viewport.y = backEnd.viewParms.viewport.y;
	backEnd.viewport.width = backEnd.viewParms.viewport.width;
	backEnd.viewport.height = backEnd.viewParms.viewport.height;

	backEnd.scissor.x = backEnd.viewParms.scissor.x;
	backEnd.scissor.y = backEnd.viewParms.scissor.y;
	backEnd.scissor.width = backEnd.viewParms.scissor.width;
	backEnd.scissor.height = backEnd.viewParms.scissor.height;

	backEnd.coordScale[0] = 1.0f / backEnd.viewport.width;
	backEnd.coordScale[1] = 1.0f / backEnd.viewport.height;

	backEnd.coordBias[0] = -backEnd.viewport.x * backEnd.coordScale[0];
	backEnd.coordBias[1] = -backEnd.viewport.y * backEnd.coordScale[1];

	backEnd.depthFilling = false;
	backEnd.debugRendering = false;

	backEnd.currentColorCaptured = SORT_BAD;
	backEnd.currentDepthCaptured = false;

	// Set up the viewport
	GL_Viewport(backEnd.viewport);

	// Set up the scissor
	GL_Scissor(backEnd.viewport);

	// Set up the depth bounds
	if (glConfig.depthBoundsTestAvailable)
		GL_DepthBounds(0.0f, 1.0f);

	// Set the projection matrix
	GL_LoadMatrix(GL_PROJECTION, backEnd.viewParms.projectionMatrix);

	// Set the modelview matrix
	GL_LoadIdentity(GL_MODELVIEW);

	// Set the GL state
	GL_PolygonMode(GL_FILL);

	GL_Disable(GL_CULL_FACE);
	GL_Disable(GL_POLYGON_OFFSET_FILL);
	GL_Disable(GL_BLEND);
	GL_Disable(GL_ALPHA_TEST);
	GL_Disable(GL_DEPTH_TEST);
	GL_Disable(GL_STENCIL_TEST);

	GL_DepthRange(0.0f, 1.0f);

	GL_ColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
	GL_DepthMask(GL_TRUE);
	GL_StencilMask(255);

	// Enable the clip plane if needed
	if (backEnd.viewParms.viewType != VIEW_MIRROR)
		qglDisable(GL_CLIP_PLANE0);
	else {
		clipPlane[0] = -DotProduct(backEnd.viewParms.axis[1], backEnd.viewParms.clipPlane.normal);
		clipPlane[1] = DotProduct(backEnd.viewParms.axis[2], backEnd.viewParms.clipPlane.normal);
		clipPlane[2] = -DotProduct(backEnd.viewParms.axis[0], backEnd.viewParms.clipPlane.normal);
		clipPlane[3] = DotProduct(backEnd.viewParms.origin, backEnd.viewParms.clipPlane.normal) - backEnd.viewParms.clipPlane.dist;

		qglEnable(GL_CLIP_PLANE0);
		qglClipPlane(GL_CLIP_PLANE0, clipPlane);
	}

	// Enable multisampling if available
	if (glConfig.multiSamples > 1)
		qglEnable(GL_MULTISAMPLE);

	// Clear the buffers
	qglClearColor(0.0f, 0.0f, 0.0f, 1.0f);
	qglClearDepth(1.0f);
	qglClearStencil(0);

	if (backEnd.viewParms.primaryView)
		qglClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
	else
		qglClear(GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

	// Check for errors
//.........这里部分代码省略.........

//.........这里部分代码省略.........
		/* Need alpha or else SGIs choose 36+ bit RGB mode */
		SDL_GL_SetAttribute( SDL_GL_ALPHA_SIZE, 1);
#endif

		SDL_GL_SetAttribute( SDL_GL_RED_SIZE, perChannelColorBits );
		SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, perChannelColorBits );
		SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, perChannelColorBits );
		SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, testDepthBits );
		SDL_GL_SetAttribute( SDL_GL_STENCIL_SIZE, testStencilBits );

		SDL_GL_SetAttribute( SDL_GL_MULTISAMPLEBUFFERS, samples ? 1 : 0 );
		SDL_GL_SetAttribute( SDL_GL_MULTISAMPLESAMPLES, samples );

		if(r_stereoEnabled->integer)
		{
			glConfig.stereoEnabled = qtrue;
			SDL_GL_SetAttribute(SDL_GL_STEREO, 1);
		}
		else
		{
			glConfig.stereoEnabled = qfalse;
			SDL_GL_SetAttribute(SDL_GL_STEREO, 0);
		}
		
		SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );

#if 0 // if multisampling is enabled on X11, this causes create window to fail.
		// If not allowing software GL, demand accelerated
		if( !r_allowSoftwareGL->integer )
			SDL_GL_SetAttribute( SDL_GL_ACCELERATED_VISUAL, 1 );
#endif

		if( ( SDL_window = SDL_CreateWindow( CLIENT_WINDOW_TITLE, x, y,
				glConfig.vidWidth, glConfig.vidHeight, flags ) ) == 0 )
		{
			ri.Printf( PRINT_DEVELOPER, "SDL_CreateWindow failed: %s\n", SDL_GetError( ) );
			continue;
		}

		if( fullscreen )
		{
			SDL_DisplayMode mode;

			switch( testColorBits )
			{
				case 16: mode.format = SDL_PIXELFORMAT_RGB565; break;
				case 24: mode.format = SDL_PIXELFORMAT_RGB24;  break;
				default: ri.Printf( PRINT_DEVELOPER, "testColorBits is %d, can't fullscreen\n", testColorBits ); continue;
			}

			mode.w = glConfig.vidWidth;
			mode.h = glConfig.vidHeight;
			mode.refresh_rate = glConfig.displayFrequency = ri.Cvar_VariableIntegerValue( "r_displayRefresh" );
			mode.driverdata = NULL;

			if( SDL_SetWindowDisplayMode( SDL_window, &mode ) < 0 )
			{
				ri.Printf( PRINT_DEVELOPER, "SDL_SetWindowDisplayMode failed: %s\n", SDL_GetError( ) );
				continue;
			}
		}

		SDL_SetWindowIcon( SDL_window, icon );

		if( ( SDL_glContext = SDL_GL_CreateContext( SDL_window ) ) == NULL )
		{
			ri.Printf( PRINT_DEVELOPER, "SDL_GL_CreateContext failed: %s\n", SDL_GetError( ) );
			continue;
		}

		qglClearColor( 0, 0, 0, 1 );
		qglClear( GL_COLOR_BUFFER_BIT );
		SDL_GL_SwapWindow( SDL_window );

		SDL_GL_SetSwapInterval( r_swapInterval->integer );

		glConfig.colorBits = testColorBits;
		glConfig.depthBits = testDepthBits;
		glConfig.stencilBits = testStencilBits;

		ri.Printf( PRINT_ALL, "Using %d color bits, %d depth, %d stencil display.\n",
				glConfig.colorBits, glConfig.depthBits, glConfig.stencilBits );
		break;
	}

	SDL_FreeSurface( icon );

	if( !SDL_window )
	{
		ri.Printf( PRINT_ALL, "Couldn't get a visual\n" );
		return RSERR_INVALID_MODE;
	}

	GLimp_DetectAvailableModes();

	glstring = (char *) qglGetString (GL_RENDERER);
	ri.Printf( PRINT_ALL, "GL_RENDERER: %s\n", glstring );

	return RSERR_OK;
}

/*
=================
RB_BeginDrawingView

Any mirrored or portaled views have already been drawn, so prepare
to actually render the visible surfaces for this view
=================
*/
void RB_BeginDrawingView (void) {
	int clearBits = 0;

	// sync with gl if needed
	if ( r_finish->integer == 1 && !glState.finishCalled ) {
		qglFinish ();
		glState.finishCalled = qtrue;
	}
	if ( r_finish->integer == 0 ) {
		glState.finishCalled = qtrue;
	}

	// we will need to change the projection matrix before drawing
	// 2D images again
	backEnd.projection2D = qfalse;

	if (glRefConfig.framebufferObject)
	{
		// FIXME: HUGE HACK: render to the screen fbo if we've already postprocessed the frame and aren't drawing more world
		// drawing more world check is in case of double renders, such as skyportals
		if (backEnd.viewParms.targetFbo == NULL)
		{
			if (!tr.renderFbo || (backEnd.framePostProcessed && (backEnd.refdef.rdflags & RDF_NOWORLDMODEL)))
			{
				FBO_Bind(NULL);
			}
			else
			{
				FBO_Bind(tr.renderFbo);
			}
		}
		else
		{
			FBO_Bind(backEnd.viewParms.targetFbo);

			// FIXME: hack for cubemap testing
			if (tr.renderCubeFbo && backEnd.viewParms.targetFbo == tr.renderCubeFbo)
			{
				//qglFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_CUBE_MAP_POSITIVE_X + backEnd.viewParms.targetFboLayer, backEnd.viewParms.targetFbo->colorImage[0]->texnum, 0);
				qglFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_CUBE_MAP_POSITIVE_X + backEnd.viewParms.targetFboLayer, tr.cubemaps[backEnd.viewParms.targetFboCubemapIndex]->texnum, 0);
			}
		}
	}

	//
	// set the modelview matrix for the viewer
	//
	SetViewportAndScissor();

	// ensures that depth writes are enabled for the depth clear
	GL_State( GLS_DEFAULT );
	// clear relevant buffers
	clearBits = GL_DEPTH_BUFFER_BIT;

	if ( r_measureOverdraw->integer || r_shadows->integer == 2 )
	{
		clearBits |= GL_STENCIL_BUFFER_BIT;
	}
	if ( r_fastsky->integer && !( backEnd.refdef.rdflags & RDF_NOWORLDMODEL ) )
	{
		clearBits |= GL_COLOR_BUFFER_BIT;	// FIXME: only if sky shaders have been used
#ifdef _DEBUG
		qglClearColor( 0.8f, 0.7f, 0.4f, 1.0f );	// FIXME: get color of sky
#else
		qglClearColor( 0.0f, 0.0f, 0.0f, 1.0f );	// FIXME: get color of sky
#endif
	}

	// clear to white for shadow maps
	if (backEnd.viewParms.flags & VPF_SHADOWMAP)
	{
		clearBits |= GL_COLOR_BUFFER_BIT;
		qglClearColor( 1.0f, 1.0f, 1.0f, 1.0f );
	}

	// clear to black for cube maps
	if (tr.renderCubeFbo && backEnd.viewParms.targetFbo == tr.renderCubeFbo)
	{
		clearBits |= GL_COLOR_BUFFER_BIT;
		qglClearColor( 0.0f, 0.0f, 0.0f, 1.0f );
	}

	qglClear( clearBits );

	if ( ( backEnd.refdef.rdflags & RDF_HYPERSPACE ) )
	{
		RB_Hyperspace();
		return;
	}
	else
	{
		backEnd.isHyperspace = qfalse;
//.........这里部分代码省略.........