Make console support 256 color mode

src/modules/main/console.cpp

@@ -1,22 +1,77 @@
 #include "console.h"
 
+const char digits[] = "0123456789abcdef";
+
 console::console(const font &f, const screen &s, void *scratch, size_t len) :
 	m_font(f),
 	m_screen(s),
 	m_size(s.width() / f.width(), s.height() / f.height()),
-	m_fg(0xffffffff),
-	m_bg(0x00000000),
+	m_fg(0xffffff),
+	m_bg(0),
 	m_first(0),
 	m_length(len),
-	m_data(static_cast<char *>(scratch))
+	m_data(nullptr),
+	m_attrs(nullptr),
+	m_palette(nullptr)
 {
-	if (len < m_size.size()) {
-		m_data = nullptr;
+	const unsigned count = m_size.size();
+	const size_t palette_size = sizeof(screen::pixel_t) * 256;
+	const size_t attrs_size = 2 * count;
+
+	if (len >= count) {
+		// We have enough scratch space to keep the contents of the screen
+		m_data = static_cast<char *>(scratch);
+		for (unsigned i = 0; i < count; ++i)
+			m_data[i] = 0;
+	}
+
+	if (len >= count + palette_size + attrs_size) {
+		// We have enough scratch space to also keep the colors of the text
+		m_palette = reinterpret_cast<screen::pixel_t *>(m_data + count);
+
+		unsigned index = 0;
+
+		// Manually add the 16 basic ANSI colors
+		m_palette[index++] = m_screen.color(0x00, 0x00, 0x00);
+		m_palette[index++] = m_screen.color(0xcd, 0x00, 0x00);
+		m_palette[index++] = m_screen.color(0x00, 0xcd, 0x00);
+		m_palette[index++] = m_screen.color(0xcd, 0xcd, 0x00);
+		m_palette[index++] = m_screen.color(0x00, 0x00, 0xee);
+		m_palette[index++] = m_screen.color(0xcd, 0x00, 0xcd);
+		m_palette[index++] = m_screen.color(0x00, 0xcd, 0xcd);
+		m_palette[index++] = m_screen.color(0xe5, 0xe5, 0xe5);
+		m_palette[index++] = m_screen.color(0x7f, 0x7f, 0x7f);
+		m_palette[index++] = m_screen.color(0xff, 0x00, 0x00);
+		m_palette[index++] = m_screen.color(0x00, 0xff, 0x00);
+		m_palette[index++] = m_screen.color(0xff, 0xff, 0x00);
+		m_palette[index++] = m_screen.color(0x00, 0x50, 0xff);
+		m_palette[index++] = m_screen.color(0xff, 0x00, 0xff);
+		m_palette[index++] = m_screen.color(0x00, 0xff, 0xff);
+		m_palette[index++] = m_screen.color(0xff, 0xff, 0xff);
+
+		// Build the high-color portion of the table
+		const uint32_t intensity[] = {0, 0x5f, 0x87, 0xaf, 0xd7, 0xff};
+		const uint32_t intensities = sizeof(intensity) / sizeof(uint32_t);
+
+		for (uint32_t r = 0; r < intensities; ++r) {
+			for (uint32_t g = 0; g < intensities; ++g) {
+				for (uint32_t b = 0; b < intensities; ++b) {
+					m_palette[index++] = m_screen.color(
+							intensity[r], intensity[g], intensity[b]);
+				}
+			}
+		}
+
+		// Build the greyscale portion of the table
+		for (uint8_t i = 0x08; i <= 0xee; i += 10)
+			m_palette[index++] = m_screen.color(i, i, i);
+
+		set_color(7, 0); // Grey on black default
+		m_attrs = reinterpret_cast<uint16_t *>(m_data + count + palette_size);
+		for (unsigned i = 0; i < count; ++i)
+			m_attrs[i] = m_attr;
 	}
 
-	const unsigned count = m_size.size();
-	for (unsigned i = 0; i < count; ++i)
-		m_data[i] = 0;
 	repaint();
 }
 
@@ -27,6 +82,13 @@ console::line_pointer(unsigned line)
 	return m_data + ((m_first + line) % m_size.y) * m_size.x;
 }
 
+uint16_t *
+console::attr_pointer(unsigned line)
+{
+	if (!m_attrs) return nullptr;
+	return m_attrs + ((m_first + line) % m_size.y) * m_size.x;
+}
+
 void
 console::repaint()
 {
@@ -35,7 +97,13 @@ console::repaint()
 
 	for (unsigned y = 0; y < m_size.y; ++y) {
 		const char *line = line_pointer(y);
+		const uint16_t *attrs = attr_pointer(y);
 		for (unsigned x = 0; x < m_size.x; ++x) {
+			const uint16_t attr = attrs[x];
+
+			set_color(static_cast<uint8_t>(attr),
+					static_cast<uint8_t>(attr >> 8));
+
 			m_font.draw_glyph(
 				m_screen,
 				line[x] ? line[x] : ' ',
@@ -47,6 +115,16 @@ console::repaint()
 	}
 }
 
+void
+console::set_color(uint8_t fg, uint8_t bg)
+{
+	if (!m_palette) return;
+
+	m_bg = m_palette[bg];
+	m_fg = m_palette[fg];
+	m_attr = (bg << 8) | fg;
+}
+
 void
 console::scroll(unsigned lines)
 {
@@ -69,11 +147,14 @@ size_t
 console::puts(const char *message)
 {
 	char *line = line_pointer(m_pos.y);
+	uint16_t *attrs = attr_pointer(m_pos.y);
+	size_t count = 0;
 
 	while (message && *message) {
 		const unsigned x = m_pos.x * m_font.width();
 		const unsigned y = m_pos.y * m_font.height();
 		const char c = *message++;
+		++count;
 
 		switch (c) {
 		case '\t':
@@ -90,7 +171,8 @@ console::puts(const char *message)
 			break;
 
 		default:
-			if (m_data) line[m_pos.x] = c;
+			if (line) line[m_pos.x] = c;
+			if (attrs) attrs[m_pos.x] = m_attr;
 			m_font.draw_glyph(m_screen, c, m_fg, m_bg, x, y);
 			m_pos.x++;
 		}
@@ -105,5 +187,8 @@ console::puts(const char *message)
 			line = line_pointer(m_pos.y);
 		}
 	}
+
+	return count;
 }
 
+