Add support for draws in vulkan read and write pixels

src/gpu/vk/GrVkGpu.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrVkGpu.h"
 
 #include "GrContextOptions.h"
@@ skipping 234 matching lines @@
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 bool GrVkGpu::onGetWritePixelsInfo(GrSurface* dstSurface, int width, int height,
                                    GrPixelConfig srcConfig, DrawPreference* drawPreference,
                                    WritePixelTempDrawInfo* tempDrawInfo) {
     if (kIndex_8_GrPixelConfig == srcConfig || GrPixelConfigIsCompressed(dstSurface->config())) {
         return false;
     }
 
-    // Currently we don't handle draws, so if the caller wants/needs to do a draw we need to fail
-    if (kNoDraw_DrawPreference != *drawPreference) {
-        return false;
+    if (dstSurface->config() == srcConfig) {
+        return true;
     }
 
-    if (dstSurface->config() != srcConfig) {
-        // TODO: This should fall back to drawing or copying to change config of dstSurface to
-        // match that of srcConfig.
-        return false;
+    GrRenderTarget* renderTarget = dstSurface->asRenderTarget();
+
+    // Start off assuming no swizzling
+    tempDrawInfo->fSwizzle = GrSwizzle::RGBA();
+    tempDrawInfo->fWriteConfig = srcConfig;
+
+    // These settings we will always want if a temp draw is performed. Initially set the config
+    // to srcConfig, though that may be modified if we decide to do a R/B swap
+    tempDrawInfo->fTempSurfaceDesc.fFlags = kNone_GrSurfaceFlags;
+    tempDrawInfo->fTempSurfaceDesc.fConfig = srcConfig;
+    tempDrawInfo->fTempSurfaceDesc.fWidth = width;
+    tempDrawInfo->fTempSurfaceDesc.fHeight = height;
+    tempDrawInfo->fTempSurfaceDesc.fSampleCnt = 0;
+    tempDrawInfo->fTempSurfaceDesc.fOrigin = kTopLeft_GrSurfaceOrigin;
+
+    if (renderTarget && this->vkCaps().isConfigRenderable(renderTarget->config(), false)) {
+        ElevateDrawPreference(drawPreference, kRequireDraw_DrawPreference);
+
+        bool configsAreRBSwaps = GrPixelConfigSwapRAndB(srcConfig) == dstSurface->config();
+
+        if (!this->vkCaps().isConfigTexturable(srcConfig) && configsAreRBSwaps) {
+            if (!this->vkCaps().isConfigTexturable(dstSurface->config())) {
+                return false;
+            }
+            tempDrawInfo->fTempSurfaceDesc.fConfig = dstSurface->config();
+            tempDrawInfo->fSwizzle = GrSwizzle::BGRA();
+            tempDrawInfo->fWriteConfig = dstSurface->config();
+        }
+        return true;
     }
 
-    return true;
+    return false;
 }
 
 bool GrVkGpu::onWritePixels(GrSurface* surface,
                             int left, int top, int width, int height,
                             GrPixelConfig config,
                             const SkTArray<GrMipLevel>& texels) {
     GrVkTexture* vkTex = static_cast<GrVkTexture*>(surface->asTexture());
     if (!vkTex) {
         return false;
     }
@@ skipping 40 matching lines @@
             int newMipLevels = texels.count();
             int currentMipLevels = vkTex->texturePriv().maxMipMapLevel() + 1;
             if (newMipLevels != currentMipLevels) {
                 if (!vkTex->reallocForMipmap(this, newMipLevels)) {
                     return false;
                 }
             }
             success = this->uploadTexDataOptimal(vkTex, left, top, width, height, config, texels);
         }
     }
-    
+
     return success;
 }
 
 bool GrVkGpu::uploadTexDataLinear(GrVkTexture* tex,
                                   int left, int top, int width, int height,
                                   GrPixelConfig dataConfig,
                                   const void* data,
                                   size_t rowBytes) {
     SkASSERT(data);
     SkASSERT(tex->isLinearTiled());
@@ skipping 157 matching lines @@
         }
 
         VkBufferImageCopy& region = regions.push_back();
         memset(&region, 0, sizeof(VkBufferImageCopy));
         region.bufferOffset = individualMipOffsets[currentMipLevel];
         region.bufferRowLength = currentWidth;
         region.bufferImageHeight = currentHeight;
         region.imageSubresource = { VK_IMAGE_ASPECT_COLOR_BIT, SkToU32(currentMipLevel), 0, 1 };
         region.imageOffset = { left, flipY ? tex->height() - top - currentHeight : top, 0 };
         region.imageExtent = { (uint32_t)currentWidth, (uint32_t)currentHeight, 1 };
-        
+
         currentWidth = SkTMax(1, currentWidth/2);
         currentHeight = SkTMax(1, currentHeight/2);
     }
 
     transferBuffer->unmap();
 
     // make sure the unmap has finished
     transferBuffer->addMemoryBarrier(this,
                                      VK_ACCESS_HOST_WRITE_BIT,
                                      VK_ACCESS_TRANSFER_READ_BIT,
@@ skipping 809 matching lines @@
 void GrVkGpu::onGetMultisampleSpecs(GrRenderTarget* rt, const GrStencilSettings&,
                                     int* effectiveSampleCnt, SkAutoTDeleteArray<SkPoint>*) {
     // TODO: stub.
     SkASSERT(!this->caps()->sampleLocationsSupport());
     *effectiveSampleCnt = rt->desc().fSampleCnt;
 }
 
 bool GrVkGpu::onGetReadPixelsInfo(GrSurface* srcSurface, int width, int height, size_t rowBytes,
                                   GrPixelConfig readConfig, DrawPreference* drawPreference,
                                   ReadPixelTempDrawInfo* tempDrawInfo) {
-    // Currently we don't handle draws, so if the caller wants/needs to do a draw we need to fail
-    if (kNoDraw_DrawPreference != *drawPreference) {
-        return false;
+    if (srcSurface->config() == readConfig) {
+        return true;
     }
 
-    if (srcSurface->config() != readConfig) {
-        // TODO: This should fall back to drawing or copying to change config of srcSurface to match
-        // that of readConfig.
-        return false;
+    if (this->vkCaps().isConfigRenderable(readConfig, false)) {
+        ElevateDrawPreference(drawPreference, kRequireDraw_DrawPreference);
+        tempDrawInfo->fTempSurfaceDesc.fConfig = readConfig;
+        tempDrawInfo->fReadConfig = readConfig;
+        return true;
     }
 
-    return true;
+    return false;
 }
 
 bool GrVkGpu::onReadPixels(GrSurface* surface,
                            int left, int top, int width, int height,
                            GrPixelConfig config,
                            void* buffer,
                            size_t rowBytes) {
     VkFormat pixelFormat;
     if (!GrPixelConfigToVkFormat(config, &pixelFormat)) {
         return false;
@@ skipping 86 matching lines @@
                                            GrVkRenderTarget* target,
                                            const SkIRect& bounds) {
     // Currently it is fine for us to always pass in 1 for the clear count even if no attachment
     // uses it. In the current state, we also only use the LOAD_OP_CLEAR for the color attachment
     // which is always at the first attachment.
     fCurrentCmdBuffer->beginRenderPass(this, renderPass, 1, colorClear, *target, bounds, true);
     fCurrentCmdBuffer->executeCommands(this, buffer);
     fCurrentCmdBuffer->endRenderPass(this);
 }