Version 0.2, more optimised rendering

README.md

@@ -20,13 +20,13 @@ The x86 (32-bit) Windows binaries can be downloaded [here](https://github.com/ma
 
 # Changelog
 
-* 0.2.0 (planned)
+* 0.2.0
 	* Refactor codebase
 	* Upgrade PDFium version
 	* Tabulating using Ctrl+Tab & Ctrl+Shift+Tab
 	* Fix most bugs (hopefully)
 	* Revamped tab close buttons
-	* [ ] More optimised rendering
+	* More optimised rendering (buffered pages)
 
 * 0.1.0
 	* Initial release

src/common.hpp

@@ -94,19 +94,28 @@ namespace pdfv
 		template<typename T>
 		struct GDI
 		{
-			T obj;
+			T obj{ nullptr };
 
+			GDI() = default;
 			constexpr GDI(const T & value) noexcept
 				: obj(value)
 			{
 			}
-			GDI(const GDI & other) = delete;
+			constexpr GDI(const GDI & other) noexcept
+				: obj(other.obj)
+			{
+			}
 			constexpr GDI(GDI && other) noexcept
 				: obj(other.obj)
 			{
 				other.obj = nullptr;
 			}
-			GDI & operator=(const GDI & other) = delete;
+			GDI & operator=(const GDI & other) noexcept
+			{
+				this->~GDI();
+				this->obj = other.obj;
+				return *this;
+			}
 			GDI & operator=(GDI && other) noexcept
 			{
 				this->~GDI();
@@ -120,6 +129,7 @@ namespace pdfv
 				{
 					auto temp{ this->obj };
 					this->obj = nullptr;
+					DEBUGPRINT("DeleteObject(%p)\n", static_cast<void *>(temp));
 					::DeleteObject(temp);
 				}
 			}
@@ -128,7 +138,7 @@ namespace pdfv
 			{
 				return this->obj;
 			}
-			[[nodiscard]] constexpr operator const T &() const noexcept
+			[[nodiscard]] constexpr operator const T & () const noexcept
 			{
 				return this->obj;
 			}

src/hdcbuffer.cpp

@@ -1 +1,33 @@
 #include "hdcbuffer.hpp"
+
+void pdfv::hdc::Renderer::clear() noexcept
+{
+	this->bmBuffer.clear();
+}
+
+[[nodiscard]] bool pdfv::hdc::Renderer::hasPage(std::size_t pageIdx) const noexcept
+{
+	return this->bmBuffer.find(pageIdx) != this->bmBuffer.end();
+}
+void pdfv::hdc::Renderer::putPage(std::size_t pageIdx, xy<int> pos, xy<int> size, std::function<Renderer::RenderT (void *)> render, void * renderArg)
+{
+	bool reRender{ true };
+	if (auto it = this->bmBuffer.find(pageIdx); it != this->bmBuffer.end())
+	{
+		if (it->second.pos == pos && it->second.size == size)
+		{
+			reRender = false;
+		}
+	}
+
+	if (reRender)
+	{
+		this->bmBuffer[pageIdx] = RenderStats(render(renderArg), pos, size);
+	}
+}
+
+pdfv::hdc::Renderer::RenderT & pdfv::hdc::Renderer::getPage(std::size_t pageIdx)
+{
+	return this->bmBuffer.at(pageIdx).hrender;
+}
+

src/hdcbuffer.hpp

@@ -2,10 +2,32 @@
 
 #include "common.hpp"
 
+#include <functional>
+#include <unordered_map>
+
 namespace pdfv::hdc
 {
-	class renderer
+	class Renderer
 	{
-
+	public:
+		using RenderT = w::GDI<HBITMAP>;
+
+		struct RenderStats
+		{
+			RenderT hrender;
+			xy<int> pos, size;
+		};
+
+	private:
+		std::unordered_map<std::size_t, RenderStats> bmBuffer;
+
+	public:
+
+		void clear() noexcept;
+
+		[[nodiscard]] bool hasPage(std::size_t pageIdx) const noexcept;
+		void putPage(std::size_t pageIdx, xy<int> pos, xy<int> size, std::function<RenderT (void *)> render, void * renderArg);
+
+		RenderT & getPage(std::size_t pageIdx);
 	};
-}
+}

src/lib.cpp

@@ -204,7 +204,7 @@ void pdfv::Pdfium::pageUnload() noexcept
 	}
 }
 
-pdfv::error::Errorcode pdfv::Pdfium::pageRender(HDC dc, pdfv::xy<int> pos, pdfv::xy<int> size) const noexcept
+pdfv::error::Errorcode pdfv::Pdfium::pageRender(HDC dc, pdfv::xy<int> pos, pdfv::xy<int> size)
 {
 	DEBUGPRINT("pdf::Pdfium::pageRender(%p, %p, %p)\n", static_cast<void *>(dc), static_cast<void *>(&pos), static_cast<void *>(&size));
 	assert(s_libInit == true);
@@ -222,7 +222,50 @@ pdfv::error::Errorcode pdfv::Pdfium::pageRender(HDC dc, pdfv::xy<int> pos, pdfv:
 		pos  = size - newsize;
 		pos /= 2;
 
-		FPDF_RenderPage(dc, this->m_fpage, pos.x, pos.y, newsize.x, newsize.y, 0, 0);
+		void * args[] = { this, dc, &newsize };
+		this->m_optRenderer.putPage(
+			this->m_fpagenum,
+			pos,
+			newsize,
+			[](void * args) -> hdc::Renderer::RenderT
+			{
+				DEBUGPRINT("render!\n");
+				auto argv = reinterpret_cast<void **>(args);
+
+				auto self = static_cast<Pdfium *>(argv[0]);
+				auto dc   = static_cast<HDC>(argv[1]);
+				auto size = static_cast<xy<int> *>(argv[2]);
+
+				auto memdc = ::CreateCompatibleDC(dc);
+				auto render = ::CreateCompatibleBitmap(dc, size->x, size->y);
+
+				auto hbmold = ::SelectObject(memdc, render);
+
+				RECT r{ .left = 0, .top = 0, .right = size->x, .bottom = size->y };
+				::FillRect(memdc, &r, reinterpret_cast<HBRUSH>(COLOR_WINDOW));
+
+				FPDF_RenderPage(memdc, self->m_fpage, 0, 0, size->x, size->y, 0, 0);
+
+				::SelectObject(memdc, hbmold);
+				::DeleteDC(memdc);
+
+				DEBUGPRINT("HBITMAP = %p (fresh)\n", static_cast<void *>(render));
+				return render;
+
+			},
+			args
+		);
+
+		const auto & render = this->m_optRenderer.getPage(this->m_fpagenum);
+
+		auto memdc = ::CreateCompatibleDC(dc);
+		DEBUGPRINT("HBITMAP = %p\n", static_cast<void *>(render.get()));
+		auto hbmold = ::SelectObject(memdc, render.get());
+
+		::BitBlt(dc, pos.x, pos.y, newsize.x, newsize.y, memdc, 0, 0, SRCCOPY);
+
+		::SelectObject(memdc, hbmold);
+		::DeleteDC(memdc);
 
 		return error::noerror;
 	}

src/lib.hpp

@@ -1,5 +1,7 @@
 #pragma once
+
 #include "common.hpp"
+#include "hdcbuffer.hpp"
 
 #include <vector>
 
@@ -18,6 +20,8 @@ namespace pdfv
 
 		std::unique_ptr<std::uint8_t> m_buf{ nullptr };
 
+		hdc::Renderer m_optRenderer;
+
 	public:
 		Pdfium() noexcept;
 		Pdfium(const Pdfium & other) = delete;
@@ -74,7 +78,7 @@ namespace pdfv
 		//	Renders the current page of the PDF document to the specified
 		//	position on the device context with specified size
 		//
-		error::Errorcode pageRender(HDC dc, pdfv::xy<int> pos, pdfv::xy<int> size) const noexcept;
+		error::Errorcode pageRender(HDC dc, pdfv::xy<int> pos, pdfv::xy<int> size);
 
 		//
 		//	Returns the page count of the currently opened PDF document