Source code of Windows XP (NT5)
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/******************************Module*Header*******************************\
* Module Name: font.c
*
* Font and text handling for the OpenGL-based 3D Text screen saver.
*
* Created: 12-24-94 -by- Marc Fortier [marcfo]
*
* Copyright (c) 1994 Microsoft Corporation
\**************************************************************************/
#include <nt.h>
#include <ntrtl.h>
#include <nturtl.h>
#include <windows.h>
#include <commdlg.h>
#include <ptypes32.h>
#include <pwin32.h>
#include <stdio.h>
#include <stdlib.h>
#include <memory.h>
#include <float.h> // for FLT_MAX
#include <GL/gl.h>
#include "sscommon.h"
#include "sstext3d.h"
#ifndef UNICODE
// Support dbcs characters (this is a patch)
#define SS_DBCS_SUPPORT 1
#endif
static LISTENTRY* FindExtendedLUTEntry( TCHAR c, WglFontContext *pwfc );
static BOOL UpdateReducedFontList( TCHAR c, LISTENTRY *ple,
WglFontContext *pwfc );
#ifdef SS_DBCS_SUPPORT
static BOOL UpdateReducedFontListDBCS( DWORD c, LISTENTRY *ple,
WglFontContext *pwfc );
#endif
static void DeleteExtendedLUTTableEntries( WglFontContext *pwfc );
static void DeleteDirectLUTTableEntries( WglFontContext *pwfc );
static void DeleteLUTEntry( LISTENTRY *ple );
/******************************Public*Routine******************************\
* CreateWglFontContext
*
* Create a WglFontContext.
*
* Initializes the look-up-table memory for characters.
* The first half of this table is a direct look-up, using the char value.
* The second half is used for unicode chars that are >256, and must be
* searched sequentially.
*
\**************************************************************************/
WglFontContext *
CreateWglFontContext( HDC hdc, int type, float fExtrusion,
float fChordalDeviation )
{
WglFontContext *pwfc;
pwfc = (WglFontContext *) LocalAlloc( LMEM_FIXED, sizeof(WglFontContext) );
if( !pwfc ) {
SS_ALLOC_FAILURE( "CreateWglFontContext" );
return NULL;
}
pwfc->hdc = hdc;
pwfc->type = type;
pwfc->extrusion = fExtrusion;
pwfc->chordalDeviation = fChordalDeviation;
pwfc->listLUT = (LISTENTRY*) LocalAlloc( LMEM_FIXED | LMEM_ZEROINIT,
SIZE_LIST_LUT * sizeof(LISTENTRY) );
if( !pwfc->listLUT ) {
LocalFree( pwfc );
SS_ALLOC_FAILURE( "CreateWglFontContext" );
return NULL;
}
pwfc->LUTIndex = 0;
return pwfc;
}
/******************************Public*Routine******************************\
* DeleteWglFontContext
*
* Delete a WglFontContext.
*
\**************************************************************************/
void
DeleteWglFontContext( WglFontContext *pwfc )
{
if( !pwfc )
return;
// Delete the extended lut table entries
DeleteExtendedLUTTableEntries( pwfc );
// Delete the direct lut table entries
DeleteDirectLUTTableEntries( pwfc );
if( pwfc->listLUT )
LocalFree( pwfc->listLUT );
LocalFree( pwfc );
}
/******************************Public*Routine******************************\
* DeleteExtendedLUTTablEntries
*
\**************************************************************************/
static void
DeleteExtendedLUTTableEntries( WglFontContext *pwfc )
{
int i;
LISTENTRY *ple = pwfc->listLUT + MAX_DIRECT_LUT;
for( i = 0; i < pwfc->LUTIndex; i ++, ple++ )
DeleteLUTEntry( ple );
pwfc->LUTIndex = 0;
}
/******************************Public*Routine******************************\
* DeleteDirectLUTTablEntries
*
\**************************************************************************/
static void
DeleteDirectLUTTableEntries( WglFontContext *pwfc )
{
int i;
LISTENTRY *ple = pwfc->listLUT;
for( i = 0; i < MAX_DIRECT_LUT; i ++, ple++ )
DeleteLUTEntry( ple );
}
/******************************Public*Routine******************************\
* DeleteLUTEntry
*
\**************************************************************************/
static void
DeleteLUTEntry( LISTENTRY *ple )
{
if( ple->listNum ) {
glDeleteLists( ple->listNum, 1 );
ple->listNum = 0;
}
if( ple->lpgmf ) {
LocalFree( ple->lpgmf );
ple->lpgmf = NULL;
}
ple->glyph = 0;
}
/**************************************************************************\
* ConvertStringToList
*
* - Translate the string into display list numbers
* - If no entry in the list table, update the table
*
\**************************************************************************/
void
ConvertStringToList( LPTSTR pszSrc, USHORT *usDst, WglFontContext *pwfc )
{
int strLen;
LISTENTRY *ple;
TCHAR c;
TUCHAR cindex; // use unsigned TCHAR for table indexing
#ifdef SS_DBCS_SUPPORT
BOOL bIsLeadByte;
#endif
if( !pwfc )
return;
/* Go thru the string, making sure every char has a display list
* Copy the display list # into usDst
*/
strLen = lstrlen( pszSrc );
if( strLen > TEXT_BUF_SIZE )
strLen = TEXT_BUF_SIZE;
/* Check for possible overflow with the extended LUT section, and
* invalidate the extended LUT if so
*/
if( pwfc->LUTIndex ) {
int roomLeft; // spaces left in extended lut table
roomLeft = SIZE_LIST_LUT - (pwfc->LUTIndex + MAX_DIRECT_LUT +1);
if( roomLeft < strLen ) {
/* If none of the characters in this string have entries in the
* table, we'll run out of room. Assume the worst, invalidate
* the whole table, and start over again.
*/
DeleteExtendedLUTTableEntries( pwfc );
}
}
for( ; strLen; strLen--, pszSrc++ ) {
c = *pszSrc;
cindex = (TUCHAR) c;
// see if char already has cmd list entry - if not, create it
#ifdef SS_DBCS_SUPPORT
bIsLeadByte = IsDBCSLeadByte(cindex);
if( !bIsLeadByte && (cindex < MAX_DIRECT_LUT) ) { // direct LUT
#else
if( cindex < MAX_DIRECT_LUT ) { // direct LUT entry
#endif
ple = &pwfc->listLUT[cindex];
if( !ple->listNum ) {
// have to create new cmd list for this glyph
if( ! UpdateReducedFontList( c, ple, pwfc ) ) {
DeleteLUTEntry( ple );
continue;
}
}
} else { // extended LUT entry
#ifdef SS_DBCS_SUPPORT
DWORD dwChar;
if( bIsLeadByte ) {
// Iterate over the lead byte
pszSrc++;
strLen--;
c = *pszSrc;
// Setup the double byte word so that :
// High byte is the lead byte
// Low byte is the next byte in the byte stream (this byte
// will be used to access the extended lut table)
dwChar = (DWORD) ( (cindex << 8) | ((TUCHAR) c) );
} else
dwChar = (DWORD) (TUCHAR) c;
if( !(ple = FindExtendedLUTEntry( c, pwfc )) ) {
ple = &pwfc->listLUT[pwfc->LUTIndex+MAX_DIRECT_LUT];
if( ! UpdateReducedFontListDBCS( dwChar, ple, pwfc ) ) {
DeleteLUTEntry( ple );
continue;
}
ple->glyph = c;
pwfc->LUTIndex++;
}
#else
if( !(ple = FindExtendedLUTEntry( c, pwfc )) ) {
ple = &pwfc->listLUT[pwfc->LUTIndex+MAX_DIRECT_LUT];
if( ! UpdateReducedFontList( c, ple, pwfc ) ) {
DeleteLUTEntry( ple );
continue;
}
ple->glyph = c;
pwfc->LUTIndex++;
}
#endif
}
*usDst++ = ple->listNum;
}
// zero terminate
*usDst = 0;
}
/******************************Public*Routine******************************\
* UpdateReducedFontList
*
* Calls wglUseFontOutlines() to create a command list for the supplied
* character.
*
* Allocates memory for the characters glyphmetrics as well
*
\**************************************************************************/
static BOOL
UpdateReducedFontList( TCHAR c, LISTENTRY *ple, WglFontContext *pwfc )
{
ple->lpgmf = (LPGLYPHMETRICSFLOAT) LocalAlloc( LMEM_FIXED,
sizeof( GLYPHMETRICSFLOAT ) );
if( !ple->lpgmf ) {
SS_ALLOC_FAILURE( "UpdateReducedFontList" );
return FAILURE;
}
// get next list # for this glyph.
ple->listNum = (USHORT) glGenLists( 1 );
if( !ple->listNum ) {
SS_WARNING( "glGenLists failed\n" );
return FAILURE;
}
if( !wglUseFontOutlines(pwfc->hdc, (TUCHAR) c, 1, ple->listNum,
pwfc->chordalDeviation,
pwfc->extrusion,
pwfc->type, ple->lpgmf) ) {
SS_WARNING( "wglUseFontOutlines failed\n" );
return FAILURE;
}
return SUCCESS;
}
#ifdef SS_DBCS_SUPPORT
// Modified version of UpdateReducedFontList that handles dbcs characters.
// This is a *patch* (as is all the SS_DBCS_SUPPORT stuff) to handle dbcs
// characters without jeopardizing SUR release stability. Later, the functions
// can be consolidated.
static BOOL
UpdateReducedFontListDBCS( DWORD c, LISTENTRY *ple, WglFontContext *pwfc )
{
ple->lpgmf = (LPGLYPHMETRICSFLOAT) LocalAlloc( LMEM_FIXED,
sizeof( GLYPHMETRICSFLOAT ) );
if( !ple->lpgmf ) {
SS_ALLOC_FAILURE( "UpdateReducedFontList" );
return FAILURE;
}
// get next list # for this glyph.
ple->listNum = (USHORT) glGenLists( 1 );
if( !ple->listNum ) {
SS_WARNING( "glGenLists failed\n" );
return FAILURE;
}
if( !wglUseFontOutlines(pwfc->hdc, c, 1, ple->listNum,
pwfc->chordalDeviation,
pwfc->extrusion,
pwfc->type, ple->lpgmf) ) {
SS_WARNING( "wglUseFontOutlines failed\n" );
return FAILURE;
}
return SUCCESS;
}
#endif
/******************************Public*Routine******************************\
* FindExtendedLUTEntry
*
* Searches through the extended character LUT, and returns ptr to the
* char's info if found, otherwise NULL.
*
\**************************************************************************/
static LISTENTRY*
FindExtendedLUTEntry( TCHAR c, WglFontContext *pwfc )
{
int i;
LISTENTRY *ple = pwfc->listLUT + MAX_DIRECT_LUT;
for( i = 0; i < pwfc->LUTIndex; i ++, ple++ ) {
if( ple->glyph == c )
return ple;
}
return NULL;
}
/******************************Public*Routine******************************\
* DrawString
*
* Draws string by calling cmd list for each char.
*
\**************************************************************************/
void
DrawString( USHORT *string,
int strLen,
WglFontContext *pwfc )
{
if( !pwfc )
return;
glCallLists(strLen, GL_UNSIGNED_SHORT, (GLushort *) string);
}
/******************************Public*Routine******************************\
* GetStringExtent
*
* Calculate a string's origin and extent in world coordinates.
*
* The origin is determined by the first character's location, and thereafter
* each char's location is determined by adding the previous char's cellInc
* values.
*
* This will work for all string orientations.
*
\**************************************************************************/
int
GetStringExtent( LPTSTR szString,
POINTFLOAT *extent,
POINTFLOAT *origin,
WglFontContext *pwfc )
{
int len, strLen;
TCHAR *c;
TUCHAR cindex;
LPGLYPHMETRICSFLOAT lpgmf;
POINTFLOAT cellOrigin = {0.0f, 0.0f};
POINTFLOAT extentOrigin = {FLT_MAX, -FLT_MAX};
POINTFLOAT extentLowerRight = {-FLT_MAX, FLT_MAX};
POINTFLOAT boxOrigin, boxLowerRight;
LISTENTRY *listLUT, *ple;
#ifdef SS_DBCS_SUPPORT
BOOL bIsLeadByte;
#endif
if( !pwfc )
return 0;
listLUT = pwfc->listLUT;
extent->x = extent->y = 0.0f;
origin->x = origin->y = 0.0f;
len = strLen = lstrlen( szString );
if( !len )
return 0; // otherwise extents will be calc'd erroneously
c = szString;
for( ; strLen; strLen--, c++ ) {
cindex = (TUCHAR) *c;
#ifdef SS_DBCS_SUPPORT
if( bIsLeadByte = IsDBCSLeadByte(cindex) ) {
// iterate over lead byte
c++;
strLen--;
cindex = (TUCHAR) *c;
}
if( !bIsLeadByte && (cindex < MAX_DIRECT_LUT) )
#else
if( cindex < MAX_DIRECT_LUT )
#endif
ple = &listLUT[cindex];
else
ple = FindExtendedLUTEntry( *c, pwfc );
lpgmf = ple->lpgmf;
if( !lpgmf )
// Memory must be running low, but keep going
continue;
// calc global position of this char's BlackBox (this is
// 'upper left')
boxOrigin.x = cellOrigin.x + lpgmf->gmfptGlyphOrigin.x;
boxOrigin.y = cellOrigin.y + lpgmf->gmfptGlyphOrigin.y;
// calc lower right position
boxLowerRight.x = boxOrigin.x + lpgmf->gmfBlackBoxX;
boxLowerRight.y = boxOrigin.y - lpgmf->gmfBlackBoxY;
// compare against the current bounding box
if( boxOrigin.x < extentOrigin.x )
extentOrigin.x = boxOrigin.x;
if( boxOrigin.y > extentOrigin.y )
extentOrigin.y = boxOrigin.y;
if( boxLowerRight.x > extentLowerRight.x )
extentLowerRight.x = boxLowerRight.x;
if( boxLowerRight.y < extentLowerRight.y )
extentLowerRight.y = boxLowerRight.y;
// set global position of next cell
cellOrigin.x = cellOrigin.x + lpgmf->gmfCellIncX;
cellOrigin.y = cellOrigin.y + lpgmf->gmfCellIncY;
}
// Check for possible total lack of glyphmetric info
if( extentOrigin.x == FLT_MAX ) {
// Can assume if this value is still maxed out that all glyphmetric
// info was NULL
origin->x = origin->y = 0.0f;
extent->x = extent->y = 0.0f;
return 0;
}
*origin = extentOrigin;
extent->x = extentLowerRight.x - extentOrigin.x;
extent->y = extentOrigin.y - extentLowerRight.y;
return len;
}