vulkan: implement graphics readback

src/modules/graphics/vulkan/GraphicsReadback.cpp

@@ -0,0 +1,73 @@
+#include "GraphicsReadback.h"
+#include "Buffer.h"
+#include "Texture.h"
+#include "Graphics.h"
+#include "data/ByteData.h"
+
+namespace love {
+namespace graphics {
+namespace vulkan {
+
+GraphicsReadback::GraphicsReadback(love::graphics::Graphics* gfx, ReadbackMethod method, love::graphics::Buffer* buffer, size_t offset, size_t size, data::ByteData* dest, size_t destoffset)
+	: graphics::GraphicsReadback(gfx, method, buffer, offset, size, dest, destoffset) {
+	vgfx = dynamic_cast<Graphics*>(gfx);
+
+	// Immediate readback of readback-type buffers doesn't need a staging buffer.
+	if (method != READBACK_IMMEDIATE || buffer->getDataUsage() != BUFFERDATAUSAGE_READBACK) {
+		stagingBuffer = gfx->getTemporaryBuffer(size, DATAFORMAT_FLOAT, 0, BUFFERDATAUSAGE_READBACK);
+		gfx->copyBuffer(buffer, stagingBuffer, offset, 0, size);
+	}
+
+	if (method == READBACK_IMMEDIATE) {
+		vgfx->submitGpuCommands(false);
+		if (stagingBuffer.get()) {
+			status = readbackBuffer(stagingBuffer, 0, size);
+			gfx->releaseTemporaryBuffer(stagingBuffer);
+		}
+		else
+			status = readbackBuffer(buffer, offset, size);
+	}
+	else
+		vgfx->addReadbackCallback([&]() {
+			status = readbackBuffer(stagingBuffer, 0, stagingBuffer->getSize());
+
+			vgfx->releaseTemporaryBuffer(stagingBuffer);
+			stagingBuffer.set(nullptr);
+		});
+}
+
+GraphicsReadback::GraphicsReadback(love::graphics::Graphics* gfx, ReadbackMethod method, love::graphics::Texture* texture, int slice, int mipmap, const Rect& rect, image::ImageData* dest, int destx, int desty)
+	: graphics::GraphicsReadback(gfx, method, texture, slice, mipmap, rect, dest, destx, desty) {
+	vgfx = dynamic_cast<Graphics*>(gfx);
+
+	size_t size = getPixelFormatSliceSize(textureFormat, rect.w, rect.h);
+
+	stagingBuffer = vgfx->getTemporaryBuffer(size, DATAFORMAT_FLOAT, 0, BUFFERDATAUSAGE_READBACK);
+
+	vgfx->copyTextureToBuffer(texture, stagingBuffer, slice, mipmap, rect, 0, 0);
+
+	vgfx->addReadbackCallback([&]() {
+		status = readbackBuffer(stagingBuffer, 0, stagingBuffer->getSize());
+
+		vgfx->releaseTemporaryBuffer(stagingBuffer);
+		stagingBuffer.set(nullptr);
+	});
+
+	if (method == READBACK_IMMEDIATE)
+		vgfx->submitGpuCommands(false);
+}
+
+GraphicsReadback::~GraphicsReadback() {
+}
+
+void GraphicsReadback::wait() {
+	if (status == STATUS_WAITING)
+		vgfx->submitGpuCommands(false);
+}
+
+void GraphicsReadback::update() {
+}
+
+} // vulkan
+} // graphics
+} // love