From c46eb09e8f49a4db5b9d6f64af0f5f4082893d9f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Axel=20D=C3=B6rfler?= <axeld@pinc-software.de>
Date: Tue, 19 Dec 2006 18:45:40 +0000
Subject: [PATCH] * The 4-bit VGA planar mode is now advertized as B_GRAY8 to
 the app_server. * The app_server now detects that this mode is being used,
 and at least correctly copies   the 32bit data to the first plane, meaning we
 have a monochrome output for now   (it crashed before, as Stefano reported).

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@19565 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 .../kernel/drivers/graphics/vesa/vesa.cpp     |  3 +-
 src/servers/app/drawing/HWInterface.cpp       | 80 +++++++++++++++----
 2 files changed, 66 insertions(+), 17 deletions(-)

diff --git a/src/add-ons/kernel/drivers/graphics/vesa/vesa.cpp b/src/add-ons/kernel/drivers/graphics/vesa/vesa.cpp
index 4614dbf1ea..720ba052a1 100644
--- a/src/add-ons/kernel/drivers/graphics/vesa/vesa.cpp
+++ b/src/add-ons/kernel/drivers/graphics/vesa/vesa.cpp
@@ -89,7 +89,8 @@ vesa_init(vesa_info &info)
 	info.shared_info->current_mode.virtual_height = bufferInfo->height;
 	switch (bufferInfo->depth) {
 		case 4:
-			// ???
+			info.shared_info->current_mode.space = B_GRAY8;
+				// the app_server is smart enough to translate this to VGA mode
 			break;
 		case 8:
 			info.shared_info->current_mode.space = B_CMAP8;
diff --git a/src/servers/app/drawing/HWInterface.cpp b/src/servers/app/drawing/HWInterface.cpp
index 4f0d73fb44..259792d3da 100644
--- a/src/servers/app/drawing/HWInterface.cpp
+++ b/src/servers/app/drawing/HWInterface.cpp
@@ -666,25 +666,73 @@ HWInterface::_CopyToFront(uint8* src, uint32 srcBPR,
 
 			break;
 		}
-		case B_GRAY8: {
-			// offset to left top pixel in dest buffer
-			dst += y * dstBPR + x;
-			int32 left = x;
-			// copy
-			// TODO: assumes BGR order, does this work on big endian as well?
-			for (; y <= bottom; y++) {
-				uint8* srcHandle = src;
-				uint8* dstHandle = dst;
-				for (x = left; x <= right; x++) {
-					*dstHandle = (308 * srcHandle[2] + 600 * srcHandle[1] + 116 * srcHandle[0]) / 1024;
-					dstHandle ++;
-					srcHandle += 4;
+		case B_GRAY8: 
+			if (frontBuffer->Width() > dstBPR) {
+				// VGA 16 color grayscale planar mode
+				dst += y * dstBPR + x / 8;
+				uint8* dstBase = dst;
+				uint8* srcBase = src;
+				int32 left = x;
+
+				// TODO: this is awfully slow...
+				// TODO: assumes BGR order
+				for (int32 plane = 0; plane < 1; plane++) {
+					// TODO: we need to select the plane here!
+					src = srcBase;
+					dst = dstBase;
+
+					for (; y <= bottom; y++) {
+						uint8* srcHandle = src;
+						uint8* dstHandle = dst;
+						uint8 current8 = dstHandle[0];
+							// we store 8 pixels before writing them back
+
+						for (x = left; x <= right; x++) {
+							uint8 pixel = (308 * srcHandle[2] + 600 * srcHandle[1]
+								+ 116 * srcHandle[0]) / 1024;
+							srcHandle += 4;
+
+							if (pixel > 128)
+								current8 |= 0x80 >> (x & 7);
+							else
+								current8 &= ~(0x80 >> (x & 7));
+
+							if ((x & 7) == 7) {
+								// last pixel in 8 pixel group
+								dstHandle[0] = current8;
+								dstHandle++;
+								current8 = dstHandle[0];
+							}
+						}
+
+						if (x & 7) {
+							// last pixel has not been written yet
+							dstHandle[0] = current8;
+						}
+						dst += dstBPR;
+						src += srcBPR;
+					}
+				}
+			} else {
+				// offset to left top pixel in dest buffer
+				dst += y * dstBPR + x;
+				int32 left = x;
+				// copy
+				// TODO: assumes BGR order, does this work on big endian as well?
+				for (; y <= bottom; y++) {
+					uint8* srcHandle = src;
+					uint8* dstHandle = dst;
+					for (x = left; x <= right; x++) {
+						*dstHandle = (308 * srcHandle[2] + 600 * srcHandle[1] + 116 * srcHandle[0]) / 1024;
+						dstHandle ++;
+						srcHandle += 4;
+					}
+					dst += dstBPR;
+					src += srcBPR;
 				}
-				dst += dstBPR;
-				src += srcBPR;
 			}
 			break;
-		}
+
 		default:
 			fprintf(stderr, "HWInterface::CopyBackToFront() - unsupported front buffer format!\n");
 			break;