Split UI code into application/plugin UI and UI library.

1 files changed, 369 insertions, 0 deletions

diff --git a/dggui/pixelbuffer.cc b/dggui/pixelbuffer.cc
new file mode 100644
index 0000000..3c666cd
--- /dev/null
+++ b/dggui/pixelbuffer.cc
@@ -0,0 +1,369 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/***************************************************************************
+ *            pixelbuffer.cc
+ *
+ *  Thu Nov 10 09:00:38 CET 2011
+ *  Copyright 2011 Bent Bisballe Nyeng
+ *  deva@aasimon.org
+ ****************************************************************************/
+
+/*
+ *  This file is part of DrumGizmo.
+ *
+ *  DrumGizmo is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU Lesser General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  DrumGizmo is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public License
+ *  along with DrumGizmo; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
+ */
+#include "pixelbuffer.h"
+
+#include <cassert>
+
+#include <cstdlib>
+#include <cstring>
+#include <algorithm>
+
+namespace GUI
+{
+
+PixelBuffer::PixelBuffer(std::size_t width, std::size_t height)
+{
+	realloc(width, height);
+}
+
+PixelBuffer::~PixelBuffer()
+{
+}
+
+void PixelBuffer::realloc(std::size_t width, std::size_t height)
+{
+	buf_data.resize(width * height * 3);
+	buf = buf_data.data();
+	this->width = width;
+	this->height = height;
+}
+
+void PixelBuffer::blendLine(std::size_t x, std::size_t y,
+                            const std::uint8_t* line, std::size_t len)
+{
+	std::uint8_t* target = buf + (x + y * width) * 3;
+	while(len)
+	{
+		if(line[3] == 0xff)
+		{
+			std::memcpy(target, line, 3);
+		}
+		else
+		{
+			unsigned int a = line[3];
+			unsigned int b = 255 - a;
+
+			target[0] = (std::uint8_t)((line[0] * a + target[0] * b) / 255);
+			target[1] = (std::uint8_t)((line[1] * a + target[1] * b) / 255);
+			target[2] = (std::uint8_t)((line[2] * a + target[2] * b) / 255);
+		}
+		target += 3;
+		line += 4;
+		--len;
+	}
+}
+
+Rect PixelBuffer::updateBuffer(std::vector<PixelBufferAlpha*>& pixel_buffers)
+{
+	bool has_dirty_rect{false};
+	Rect dirty_rect;
+
+	for(const auto& pixel_buffer : pixel_buffers)
+	{
+		if(pixel_buffer->dirty)
+		{
+			auto x1 = (std::size_t)std::max(pixel_buffer->x, 0);
+			auto x2 = (std::size_t)std::max((pixel_buffer->x + (int)pixel_buffer->width), 0);
+			auto y1 = (std::size_t)std::max(pixel_buffer->y, 0);
+			auto y2 = (std::size_t)std::max((pixel_buffer->y + (int)pixel_buffer->height), 0);
+
+			pixel_buffer->dirty = false;
+			if(!has_dirty_rect)
+			{
+				// Insert this area:
+				dirty_rect = {x1, y1, x2, y2};
+				has_dirty_rect = true;
+			}
+			else
+			{
+				// Expand existing area:
+				auto x1_0 = dirty_rect.x1;
+				auto y1_0 = dirty_rect.y1;
+				auto x2_0 = dirty_rect.x2;
+				auto y2_0 = dirty_rect.y2;
+				dirty_rect = {
+					(x1_0 < x1) ? x1_0 : x1,
+					(y1_0 < y1) ? y1_0 : y1,
+					(x2_0 > x2) ? x2_0 : x2,
+					(y2_0 > y2) ? y2_0 : y2
+				};
+			}
+		}
+
+		if(pixel_buffer->has_last)
+		{
+			auto x1 = (std::size_t)pixel_buffer->last_x;
+			auto x2 = (std::size_t)(pixel_buffer->last_x + pixel_buffer->last_width);
+			auto y1 = (std::size_t)pixel_buffer->last_y;
+			auto y2 = (std::size_t)(pixel_buffer->last_y + pixel_buffer->last_height);
+
+			pixel_buffer->has_last = false;
+			if(!has_dirty_rect)
+			{
+				// Insert this area:
+				dirty_rect = {x1, y1, x2, y2};
+				has_dirty_rect = true;
+			}
+			else
+			{
+				// Expand existing area:
+				auto x1_0 = dirty_rect.x1;
+				auto y1_0 = dirty_rect.y1;
+				auto x2_0 = dirty_rect.x2;
+				auto y2_0 = dirty_rect.y2;
+				dirty_rect = {
+					(x1_0 < x1) ? x1_0 : x1,
+					(y1_0 < y1) ? y1_0 : y1,
+					(x2_0 > x2) ? x2_0 : x2,
+					(y2_0 > y2) ? y2_0 : y2
+				};
+			}
+		}
+	}
+
+	if(!has_dirty_rect)
+	{
+		return {};
+	}
+
+	for(const auto& pixel_buffer : pixel_buffers)
+	{
+		if(!pixel_buffer->visible)
+		{
+			continue;
+		}
+
+		int update_width = pixel_buffer->width;
+		int update_height = pixel_buffer->height;
+
+		// Skip buffer if not inside window.
+		if(((int)width < pixel_buffer->x) ||
+		   ((int)height < pixel_buffer->y))
+		{
+			continue;
+		}
+
+		if(update_width > ((int)width - pixel_buffer->x))
+		{
+			update_width = ((int)width - pixel_buffer->x);
+		}
+
+		if(update_height > ((int)height - pixel_buffer->y))
+		{
+			update_height = ((int)height - pixel_buffer->y);
+		}
+
+		auto from_x  = (int)dirty_rect.x1 - pixel_buffer->x;
+		from_x = std::max(0, from_x);
+		auto from_y  = (int)dirty_rect.y1 - pixel_buffer->y;
+		from_y = std::max(0, from_y);
+
+		auto to_x = (int)dirty_rect.x2 - pixel_buffer->x;
+		to_x = std::min(to_x, (int)update_width);
+		auto to_y = (int)dirty_rect.y2 - pixel_buffer->y;
+		to_y = std::min(to_y, (int)update_height);
+
+		if(to_x < from_x)
+		{
+			continue;
+		}
+
+		for(int y = from_y; y < to_y; y++)
+		{
+			blendLine(pixel_buffer->x + from_x,
+			          pixel_buffer->y + y,
+			          pixel_buffer->getLine(from_x, y),
+			          to_x - from_x);
+		}
+	}
+
+	dirty_rect.x2 = std::min(width, dirty_rect.x2);
+	dirty_rect.y2 = std::min(height, dirty_rect.y2);
+
+	// Make sure we don't try to paint a rect backwards.
+	if(dirty_rect.x1 > dirty_rect.x2)
+	{
+		std::swap(dirty_rect.x1, dirty_rect.x2);
+	}
+
+	if(dirty_rect.y1 > dirty_rect.y2)
+	{
+		std::swap(dirty_rect.y1, dirty_rect.y2);
+	}
+
+	return dirty_rect;
+}
+
+PixelBufferAlpha::PixelBufferAlpha(std::size_t width, std::size_t height)
+{
+	realloc(width, height);
+}
+
+PixelBufferAlpha::~PixelBufferAlpha()
+{
+}
+
+void PixelBufferAlpha::realloc(std::size_t width, std::size_t height)
+{
+	buf_data.resize(width * height * 4);
+	buf = buf_data.data();
+	this->width = width;
+	this->height = height;
+	clear();
+}
+
+void PixelBufferAlpha::clear()
+{
+	std::memset(buf, 0, width * height * 4);
+}
+
+void PixelBufferAlpha::setPixel(std::size_t x, std::size_t y, const Colour& c)
+{
+	std::uint8_t* pixel = buf + (x + y * width) * 4;
+	std::memcpy(pixel, c.data(), 4);
+}
+
+void PixelBufferAlpha::writeLine(std::size_t x, std::size_t y,
+                                 const std::uint8_t* line, std::size_t len)
+{
+	if(x >= width || y >= height)
+	{
+		return;
+	}
+
+	if(x + len > width)
+	{
+		len = width - x;
+	}
+
+	auto offset = buf + (x + y * width) * 4;
+
+	std::memcpy(offset, line, len * 4);
+}
+
+
+// SIMD: https://github.com/WojciechMula/toys/blob/master/blend_32bpp/blend_32bpp.c
+// Alpha blending: http://en.wikipedia.org/wiki/Alpha_compositing
+
+void PixelBufferAlpha::blendLine(std::size_t x, std::size_t y,
+                                 const std::uint8_t* line, std::size_t len)
+{
+	if(x >= width || y >= height)
+	{
+		return;
+	}
+
+	if(x + len > width)
+	{
+		len = width - x;
+	}
+
+	int a, b;
+	std::uint8_t* target = buf + (x + y * width) * 4;
+	while(len)
+	{
+		if(line[3] == 0xff)
+		{
+			const std::uint8_t* end = line;
+			while(end[3] == 0xff && end < line + len * 4)
+			{
+				end += 4;
+			}
+			auto chunk_len = end - line;
+			std::memcpy(target, line, chunk_len);
+			line += chunk_len;
+			target += chunk_len;
+			len -= chunk_len / 4;
+			continue;
+		}
+		else if(line[3] == 0)
+		{
+			// Do nothing
+		}
+		else
+		{
+			a = line[3];
+			b = target[3] * (255 - a) / 255;
+
+			target[0] = (line[0] * a + target[0] * b) / (a + b);
+			target[1] = (line[1] * a + target[1] * b) / (a + b);
+			target[2] = (line[2] * a + target[2] * b) / (a + b);
+			target[3] = (int)target[3] + line[3] * (255 - target[3]) / 255;
+		}
+
+		line += 4;
+		target += 4;
+		--len;
+	}
+}
+
+void PixelBufferAlpha::addPixel(std::size_t x, std::size_t y, const Colour& c)
+{
+	if(x >= width || y >= height)
+	{
+		return; // out of bounds
+	}
+
+	const std::uint8_t* colour = c.data();
+
+	if(colour[3] == 0)
+	{
+		return;
+	}
+
+	int a, b;
+	std::uint8_t* target = buf + (x + y * width) * 4;
+
+	if(colour[3] == 0xff)
+	{
+		std::memcpy(target, colour, 4);
+	}
+	else
+	{
+		a = colour[3];
+		b = target[3] * (255 - a) / 255;
+
+		target[0] = (colour[0] * a + target[0] * b) / (a + b);
+		target[1] = (colour[1] * a + target[1] * b) / (a + b);
+		target[2] = (colour[2] * a + target[2] * b) / (a + b);
+		target[3] = (int)target[3] + colour[3] * (255 - target[3]) / 255;
+	}
+}
+
+const Colour& PixelBufferAlpha::pixel(std::size_t x, std::size_t y) const
+{
+	static Colour c;
+	std::memcpy(c.data(), buf + (x + y * width) * 4, 4);
+	return c;
+}
+
+const std::uint8_t* PixelBufferAlpha::getLine(std::size_t x, std::size_t y) const
+{
+	return buf + (x + y * width) * 4;
+}
+
+} // GUI::