context.c

这是一个开放源代码的与WINNT/WIN2K/WIN2003兼容的操作系统

    glDisable(GL_CLIP_PLANE5); checkGLcall("glDisable(clip plane 5)");
    Context_MarkStateDirty(context, STATE_RENDER(WINED3DRS_CLIPPING));

    glViewport(0, 0, width, height);
    checkGLcall("glViewport");
    Context_MarkStateDirty(context, STATE_VIEWPORT);

    if(GL_SUPPORT(NV_TEXTURE_SHADER2)) {
        glDisable(GL_TEXTURE_SHADER_NV);
        checkGLcall("glDisable(GL_TEXTURE_SHADER_NV)");
    }
}

/*****************************************************************************
 * findThreadContextForSwapChain
 *
 * Searches a swapchain for all contexts and picks one for the thread tid.
 * If none can be found the swapchain is requested to create a new context
 *
 *****************************************************************************/
static WineD3DContext *findThreadContextForSwapChain(IWineD3DSwapChain *swapchain, DWORD tid) {
    int i;

    for(i = 0; i < ((IWineD3DSwapChainImpl *) swapchain)->num_contexts; i++) {
        if(((IWineD3DSwapChainImpl *) swapchain)->context[i]->tid == tid) {
            return ((IWineD3DSwapChainImpl *) swapchain)->context[i];
        }

    }

    /* Create a new context for the thread */
    return IWineD3DSwapChainImpl_CreateContextForThread(swapchain);
}

/*****************************************************************************
 * FindContext
 *
 * Finds a context for the current render target and thread
 *
 * Parameters:
 *  target: Render target to find the context for
 *  tid: Thread to activate the context for
 *
 * Returns: The needed context
 *
 *****************************************************************************/
static inline WineD3DContext *FindContext(IWineD3DDeviceImpl *This, IWineD3DSurface *target, DWORD tid) {
    IWineD3DSwapChain *swapchain = NULL;
    HRESULT hr;
    BOOL readTexture = wined3d_settings.offscreen_rendering_mode != ORM_FBO && This->render_offscreen;
    WineD3DContext *context = This->activeContext;
    BOOL oldRenderOffscreen = This->render_offscreen;

    hr = IWineD3DSurface_GetContainer(target, &IID_IWineD3DSwapChain, (void **) &swapchain);
    if(hr == WINED3D_OK && swapchain) {
        TRACE("Rendering onscreen\n");

        context = findThreadContextForSwapChain(swapchain, tid);

        This->render_offscreen = FALSE;
        /* The context != This->activeContext will catch a NOP context change. This can occur
         * if we are switching back to swapchain rendering in case of FBO or Back Buffer offscreen
         * rendering. No context change is needed in that case
         */

        if (wined3d_settings.offscreen_rendering_mode == ORM_BACKBUFFER) {
            if(((IWineD3DSwapChainImpl *) swapchain)->backBuffer) {
                glDrawBuffer(GL_BACK);
                checkGLcall("glDrawBuffer(GL_BACK)");
            } else {
                glDrawBuffer(GL_FRONT);
                checkGLcall("glDrawBuffer(GL_FRONT)");
            }
        } else if(wined3d_settings.offscreen_rendering_mode == ORM_PBUFFER) {
            if(This->pbufferContext && tid == This->pbufferContext->tid) {
                This->pbufferContext->tid = 0;
            }
        }
        IWineD3DSwapChain_Release(swapchain);

        if(oldRenderOffscreen) {
            Context_MarkStateDirty(context, WINED3DRS_CULLMODE);
            Context_MarkStateDirty(context, WINED3DTS_PROJECTION);
            Context_MarkStateDirty(context, STATE_VDECL);
            Context_MarkStateDirty(context, STATE_VIEWPORT);
            Context_MarkStateDirty(context, STATE_SCISSORRECT);
        }

    } else {
        TRACE("Rendering offscreen\n");
        This->render_offscreen = TRUE;

        switch(wined3d_settings.offscreen_rendering_mode) {
            case ORM_FBO:
                /* FBOs do not need a different context. Stay with whatever context is active at the moment */
                if(This->activeContext && tid == This->lastThread) {
                    context = This->activeContext;
                } else {
                    /* This may happen if the app jumps streight into offscreen rendering
                     * Start using the context of the primary swapchain. tid == 0 is no problem
                     * for findThreadContextForSwapChain.
                     *
                     * Can also happen on thread switches - in that case findThreadContextForSwapChain
                     * is perfect to call.
                     */
                    context = findThreadContextForSwapChain(This->swapchains[0], tid);
                }
                break;

            case ORM_PBUFFER:
            {
                IWineD3DSurfaceImpl *targetimpl = (IWineD3DSurfaceImpl *) target;
                if(This->pbufferContext == NULL ||
                   This->pbufferWidth < targetimpl->currentDesc.Width ||
                   This->pbufferHeight < targetimpl->currentDesc.Height) {
                    if(This->pbufferContext) {
                        DestroyContext(This, This->pbufferContext);
                    }

                    /* The display is irrelevant here, the window is 0. But CreateContext needs a valid X connection.
                     * Create the context on the same server as the primary swapchain. The primary swapchain is exists at this point.
                     */
                    This->pbufferContext = CreateContext(This, targetimpl,
                            ((IWineD3DSwapChainImpl *) This->swapchains[0])->context[0]->win_handle,
                            TRUE /* pbuffer */, &((IWineD3DSwapChainImpl *)This->swapchains[0])->presentParms);
                    This->pbufferWidth = targetimpl->currentDesc.Width;
                    This->pbufferHeight = targetimpl->currentDesc.Height;
                   }

                   if(This->pbufferContext) {
                       if(This->pbufferContext->tid != 0 && This->pbufferContext->tid != tid) {
                           FIXME("The PBuffr context is only supported for one thread for now!\n");
                       }
                       This->pbufferContext->tid = tid;
                       context = This->pbufferContext;
                       break;
                   } else {
                       ERR("Failed to create a buffer context and drawable, falling back to back buffer offscreen rendering\n");
                       wined3d_settings.offscreen_rendering_mode = ORM_BACKBUFFER;
                   }
            }

            case ORM_BACKBUFFER:
                /* Stay with the currently active context for back buffer rendering */
                if(This->activeContext && tid == This->lastThread) {
                    context = This->activeContext;
                } else {
                    /* This may happen if the app jumps streight into offscreen rendering
                     * Start using the context of the primary swapchain. tid == 0 is no problem
                     * for findThreadContextForSwapChain.
                     *
                     * Can also happen on thread switches - in that case findThreadContextForSwapChain
                     * is perfect to call.
                     */
                    context = findThreadContextForSwapChain(This->swapchains[0], tid);
                }
                glDrawBuffer(This->offscreenBuffer);
                checkGLcall("glDrawBuffer(This->offscreenBuffer)");
                break;
        }

        if (wined3d_settings.offscreen_rendering_mode != ORM_FBO) {
            /* Make sure we have a OpenGL texture name so the PreLoad() used to read the buffer
             * back when we are done won't mark us dirty.
             */
            IWineD3DSurface_PreLoad(target);
        }

        if(!oldRenderOffscreen) {
            Context_MarkStateDirty(context, WINED3DRS_CULLMODE);
            Context_MarkStateDirty(context, WINED3DTS_PROJECTION);
            Context_MarkStateDirty(context, STATE_VDECL);
            Context_MarkStateDirty(context, STATE_VIEWPORT);
            Context_MarkStateDirty(context, STATE_SCISSORRECT);
        }
    }
    if (readTexture) {
        BOOL oldInDraw = This->isInDraw;

        /* PreLoad requires a context to load the texture, thus it will call ActivateContext.
         * Set the isInDraw to true to signal PreLoad that it has a context. Will be tricky
         * when using offscreen rendering with multithreading
         */
        This->isInDraw = TRUE;

        /* Do that before switching the context:
         * Read the back buffer of the old drawable into the destination texture
         */
        IWineD3DSurface_PreLoad(This->lastActiveRenderTarget);

        /* Assume that the drawable will be modified by some other things now */
        ((IWineD3DSurfaceImpl *) This->lastActiveRenderTarget)->Flags &= ~SFLAG_INDRAWABLE;

        This->isInDraw = oldInDraw;
    }

    if(oldRenderOffscreen != This->render_offscreen && This->depth_copy_state != WINED3D_DCS_NO_COPY) {
        This->depth_copy_state = WINED3D_DCS_COPY;
    }
    return context;
}

/*****************************************************************************
 * ActivateContext
 *
 * Finds a rendering context and drawable matching the device and render
 * target for the current thread, activates them and puts them into the
 * requested state.
 *
 * Params:
 *  This: Device to activate the context for
 *  target: Requested render target
 *  usage: Prepares the context for blitting, drawing or other actions
 *
 *****************************************************************************/
void ActivateContext(IWineD3DDeviceImpl *This, IWineD3DSurface *target, ContextUsage usage) {
    DWORD                         tid = GetCurrentThreadId();
    int                           i;
    DWORD                         dirtyState, idx;
    BYTE                          shift;
    WineD3DContext                *context;

    TRACE("(%p): Selecting context for render target %p, thread %d\n", This, target, tid);

    ENTER_GL();
    if(This->lastActiveRenderTarget != target || tid != This->lastThread) {
        context = FindContext(This, target, tid);
        This->lastActiveRenderTarget = target;
        This->lastThread = tid;
    } else {
        /* Stick to the old context */
        context = This->activeContext;
    }

    /* Activate the opengl context */
    if(context != This->activeContext) {
        BOOL ret;
        TRACE("Switching gl ctx to %p, hdc=%p ctx=%p\n", context, context->hdc, context->glCtx);
        LEAVE_GL();
        ret = pwglMakeCurrent(context->hdc, context->glCtx);
        ENTER_GL();
        if(ret == FALSE) {
            ERR("Failed to activate the new context\n");
        }
        This->activeContext = context;
    }

    switch(usage) {
        case CTXUSAGE_RESOURCELOAD:
            /* This does not require any special states to be set up */
            break;

        case CTXUSAGE_CLEAR:
            if(context->last_was_blit && GL_SUPPORT(NV_TEXTURE_SHADER2)) {
                glEnable(GL_TEXTURE_SHADER_NV);
                checkGLcall("glEnable(GL_TEXTURE_SHADER_NV)");
            }

            glEnable(GL_SCISSOR_TEST);
            checkGLcall("glEnable GL_SCISSOR_TEST");
            context->last_was_blit = FALSE;
            Context_MarkStateDirty(context, STATE_RENDER(WINED3DRS_SCISSORTESTENABLE));
            Context_MarkStateDirty(context, STATE_SCISSORRECT);
            break;

        case CTXUSAGE_DRAWPRIM:
            /* This needs all dirty states applied */
            if(context->last_was_blit && GL_SUPPORT(NV_TEXTURE_SHADER2)) {
                glEnable(GL_TEXTURE_SHADER_NV);
                checkGLcall("glEnable(GL_TEXTURE_SHADER_NV)");
            }

            IWineD3DDeviceImpl_FindTexUnitMap(This);

            for(i=0; i < context->numDirtyEntries; i++) {
                dirtyState = context->dirtyArray[i];
                idx = dirtyState >> 5;
                shift = dirtyState & 0x1f;
                context->isStateDirty[idx] &= ~(1 << shift);
                StateTable[dirtyState].apply(dirtyState, This->stateBlock, context);
            }
            context->numDirtyEntries = 0; /* This makes the whole list clean */
            context->last_was_blit = FALSE;
            break;

        case CTXUSAGE_BLIT:
            SetupForBlit(This, context,
                         ((IWineD3DSurfaceImpl *)target)->currentDesc.Width,
                         ((IWineD3DSurfaceImpl *)target)->currentDesc.Height);
            break;

        default:
            FIXME("Unexpected context usage requested\n");
    }
    LEAVE_GL();
}