/**
* PROJECT: ExectOS
* COPYRIGHT: See COPYING.md in the top level directory
* FILE: xtoskrnl/hl/fbdev.c
* DESCRIPTION: FrameBuffer support
* DEVELOPERS: Rafal Kupiec <belliash@codingworkshop.eu.org>
*/
#include <xtos.h>
#include <xtfont.h>
/**
* Clears the screen by drawing a box filled with specified color.
*
* @param Color
* Specifies the color of the box used to fill the screen in (A)RGB format.
*
* @return This routine does not return any value.
*
* @since XT 1.0
*/
XTAPI
VOID
HlClearScreen(IN ULONG Color)
{
SIZE_T Line, PositionX, PositionY;
ULONG BackgroundColor;
PULONG FrameBuf;
/* Make sure frame buffer is already initialized */
if(HlpFrameBufferData.Initialized == FALSE)
{
/* Unable to operate on non-initialized frame buffer */
return;
}
/* Get pointer to frame buffer */
FrameBuf = HlpFrameBufferData.Address;
/* Convert background color */
BackgroundColor = HlpRGBColor(Color);
/* Fill the screen with a black box */
for(PositionY = 0; PositionY < HlpFrameBufferData.Height; PositionY++)
{
Line = PositionY * HlpFrameBufferData.PixelsPerScanLine;
for(PositionX = 0; PositionX < HlpFrameBufferData.Width; PositionX++)
{
FrameBuf[Line + PositionX] = BackgroundColor;
}
}
}
/**
* Draw a pixel on the screen at the given position and color.
*
* @param PositionX
* Supplies the X coordinate of the pixel.
*
* @param PositionY
* Supplies the Y coordinate of the pixel.
*
* @param Color
* Specifies the color of the pixel in (A)RGB format.
*
* @return This routine does not return any value.
*
* @since XT 1.0
*/
XTAPI
VOID
HlDrawPixel(IN ULONG PositionX,
IN ULONG PositionY,
IN ULONG Color)
{
SIZE_T FrameBufferIndex;
/* Make sure frame buffer is already initialized */
if(HlpFrameBufferData.Initialized == FALSE)
{
/* Unable to operate on non-initialized frame buffer */
return;
}
/* Make sure point is not offscreen */
if(PositionX >= HlpFrameBufferData.Width || PositionY >= HlpFrameBufferData.Height || Color > 0xFFFFFFFF)
{
/* Invalid pixel position or color given */
return;
}
/* Calculate the index of the pixel in the frame buffer memory using the provided x and y coordinates */
FrameBufferIndex = 4 * HlpFrameBufferData.PixelsPerScanLine * PositionY + 4 * PositionX;
/* Set the color of the pixel by writing to the corresponding memory location */
*((PULONG)(HlpFrameBufferData.Address + FrameBufferIndex)) = HlpRGBColor(Color);
}
/**
* Initializes frame buffer display.
*
* @return This routine returns a status code.
*
* @since XT 1.0
*/
XTAPI
XTSTATUS
HlInitializeFrameBuffer(VOID)
{
PSYSTEM_RESOURCE_FRAMEBUFFER FrameBufferResource;
PSYSTEM_RESOURCE_HEADER SystemResource;
XTSTATUS Status;
/* Check if display already initialized */
if(HlpFrameBufferData.Initialized)
{
/* Nothing to do */
return STATUS_SUCCESS;
}
/* Get FrameBuffer system resource */
Status = KeGetSystemResource(SystemResourceFrameBuffer, &SystemResource);
if(Status != STATUS_SUCCESS)
{
/* Resource not found */
return STATUS_NOT_FOUND;
}
/* Cast system resource to FrameBuffer resource */
FrameBufferResource = (PSYSTEM_RESOURCE_FRAMEBUFFER)SystemResource;
/* Check if bootloader provided a framebuffer address */
if(!FrameBufferResource->Header.VirtualAddress)
{
/* Display probably not initialized */
return STATUS_DEVICE_NOT_READY;
}
/* Check if bootloader provided a custom font */
if(FrameBufferResource->Font)
{
/* Use custom font */
HlpFrameBufferData.Font = FrameBufferResource->Font;
}
else
{
/* Use default font */
HlpFrameBufferData.Font = (PVOID)&XtFbDefaultFont;
}
/* Save framebuffer information and mark display as initialized */
HlpFrameBufferData.Address = FrameBufferResource->Header.VirtualAddress;
HlpFrameBufferData.Width = FrameBufferResource->Width;
HlpFrameBufferData.Height = FrameBufferResource->Height;
HlpFrameBufferData.BitsPerPixel = FrameBufferResource->BitsPerPixel;
HlpFrameBufferData.PixelsPerScanLine = FrameBufferResource->PixelsPerScanLine;
HlpFrameBufferData.Pitch = FrameBufferResource->Pitch;
HlpFrameBufferData.Pixels.BlueShift = FrameBufferResource->Pixels.BlueShift;
HlpFrameBufferData.Pixels.BlueSize = FrameBufferResource->Pixels.BlueSize;
HlpFrameBufferData.Pixels.GreenShift = FrameBufferResource->Pixels.GreenShift;
HlpFrameBufferData.Pixels.GreenSize = FrameBufferResource->Pixels.GreenSize;
HlpFrameBufferData.Pixels.RedShift = FrameBufferResource->Pixels.RedShift;
HlpFrameBufferData.Pixels.RedSize = FrameBufferResource->Pixels.RedSize;
HlpFrameBufferData.Pixels.ReservedShift = FrameBufferResource->Pixels.ReservedShift;
HlpFrameBufferData.Pixels.ReservedSize = FrameBufferResource->Pixels.ReservedSize;
HlpFrameBufferData.Initialized = TRUE;
/* Clear screen */
HlClearScreen(0x00000000);
/* Return success */
return STATUS_SUCCESS;
}
/**
* Puts a wide character on the framebuffer at the given position and color using the SSFN font.
*
* @param PositionX
* Supplies the X coordinate of the character.
*
* @param PositionY
* Supplies the Y coordinate of the character.
*
* @param Color
* Supplies the font color in (A)RGB format.
*
* @param WideCharacter
* Supplies the wide character to be drawn on the framebuffer.
*
* @return This routine does not return any value.
*
* @since XT 1.0
*/
XTAPI
VOID
HlPutCharacter(IN ULONG PositionX,
IN ULONG PositionY,
IN ULONG Color,
IN WCHAR WideCharacter)
{
UINT CurrentFragment, Glyph, GlyphLimit, Index, Line, Mapping;
PUCHAR Character, CharacterMapping, Fragment;
UINT_PTR GlyphPixel, Pixel;
PSSFN_FONT_HEADER FbFont;
ULONG FontColor;
/* Make sure frame buffer is already initialized */
if(HlpFrameBufferData.Initialized == FALSE)
{
/* Unable to operate on non-initialized frame buffer */
return;
}
/* Get pointers to font data */
FbFont = (PSSFN_FONT_HEADER)HlpFrameBufferData.Font;
CharacterMapping = (PUCHAR)FbFont + FbFont->CharactersOffset;
/* Find the character in the font's character table */
Character = 0;
for(Index = 0; Index < 0x110000; Index++)
{
if(CharacterMapping[0] == 0xFF)
{
/* Skip 65535 code points */
Index += 65535;
CharacterMapping++;
}
else if((CharacterMapping[0] & 0xC0) == 0xC0)
{
/* Skip (N << 8 + additional byte) + 1 code points (up to 16128) */
Index += (((CharacterMapping[0] & 0x3F) << 8) | CharacterMapping[1]);
CharacterMapping += 2;
}
else if((CharacterMapping[0] & 0xC0) == 0x80)
{
/* Skip N + 1 code points (up to 64) */
Index += (CharacterMapping[0] & 0x3F);
CharacterMapping++;
}
else
{
/* There's a glyph for this character, check if it matches */
if(Index == WideCharacter)
{
/* Found the character, break loop */
Character = CharacterMapping;
break;
}
/* Move to next character table entry */
CharacterMapping += (6 + CharacterMapping[1] * (CharacterMapping[0] & 0x40 ? 6 : 5));
}
}
/* Make sure the character has been found in the font */
if(!Character)
{
/* Character not found, don't draw anything */
return;
}
/* Find the glyph position on the frame buffer and set font color */
GlyphPixel = (UINT_PTR)HlpFrameBufferData.Address + PositionY * HlpFrameBufferData.Pitch + PositionX * 4;
FontColor = HlpRGBColor(Color);
/* Check all kerning fragments */
Mapping = 0;
CharacterMapping = Character + 6;
for(Index = 0; Index < Character[1]; Index++)
{
/* Check if number of fragments is not exceeded */
if(CharacterMapping[0] == 255 && CharacterMapping[1] == 255)
{
/* Get next mapping */
continue;
}
/* Get pointer to fragment */
Fragment = (PUCHAR)FbFont + (CharacterMapping[2] |
(CharacterMapping[3] << 8) |
(CharacterMapping[4] << 16) |
((Character[0] & 0x40) ? (CharacterMapping[5] << 24) : 0));
/* Check if fragment is printable */
if((Fragment[0] & 0xE0) != 0x80)
{
/* Skip fragment */
continue;
}
/* Get initial glyph line */
GlyphPixel += (CharacterMapping[1] - Mapping) * HlpFrameBufferData.Pitch;
Mapping = CharacterMapping[1];
/* Extract glyph data from fragments table and advance */
Glyph = ((Fragment[0] & 0x1F) + 1) << 3;
GlyphLimit = Fragment[1] + 1;
Fragment += 2;
/* Look for kerning group for next code point */
CurrentFragment = 1;
while(GlyphLimit--)
{
Pixel = GlyphPixel;
for(Line = 0; Line < Glyph; Line++)
{
/* Decode compressed offsets */
if(CurrentFragment > 0x80)
{
/* Advance to next fragment */
Fragment++;
CurrentFragment = 1;
}
/* Check if pixel should be drawn */
if(*Fragment & CurrentFragment)
{
/* Draw glyph pixel */
*((PULONG)Pixel) = FontColor;
}
/* Advance pixel pointer */
Pixel += 4;
CurrentFragment <<= 1;
}
/* Advance to next line and increase mapping */
GlyphPixel += HlpFrameBufferData.Pitch;
Mapping++;
}
/* Get next mapping */
CharacterMapping += Character[0] & 0x40 ? 6 : 5;
}
}
/**
* Converts color format from (A)RGB one expected by current FrameBuffer.
*
* @param Color
* Specifies the color in (A)RGB format.
*
* @return Returns the color in FrameBuffer format.
*
* @since XT 1.0
*/
XTAPI
ULONG
HlpRGBColor(IN ULONG Color)
{
USHORT Blue, Green, Red, Reserved;
/* Extract color components from (A)RGB value */
Blue = (USHORT)(Color & 0xFF);
Green = (USHORT)((Color >> 8) & 0xFF);
Red = (USHORT)((Color >> 16) & 0xFF);
Reserved = (USHORT)((Color >> 24) & 0xFF);
/* Return color in FrameBuffer pixel format */
return (ULONG)((Blue << HlpFrameBufferData.Pixels.BlueShift) | (Green << HlpFrameBufferData.Pixels.GreenShift) |
(Red << HlpFrameBufferData.Pixels.RedShift) | (Reserved << HlpFrameBufferData.Pixels.ReservedShift));
}