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(svn r14479) -Add: initial (optional) support for handling bidirectional scripts and connecting Arabic characters.

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rubidium
2008-10-17 17:14:09 +00:00
parent b6ca10b05a
commit ae0715e8c3
2 changed files with 189 additions and 14 deletions
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142
src/gfx.cpp
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@@ -51,6 +51,7 @@ DrawPixelInfo *_cur_dpi;
byte _colour_gradient[COLOUR_END][8];
static void GfxMainBlitter(const Sprite *sprite, int x, int y, BlitterMode mode, const SubSprite *sub = NULL);
static int ReallyDoDrawString(const char *string, int x, int y, uint16 real_colour, bool parse_string_also_when_clipped = false);
FontSize _cur_fontsize;
static FontSize _last_fontsize;
@@ -238,6 +239,74 @@ void DrawBox(int x, int y, int dx1, int dy1, int dx2, int dy2, int dx3, int dy3)
}
#if !defined(WITH_ICU)
static void HandleBiDiAndArabicShapes(char *text, const char *lastof) {}
#else
#include "unicode/ubidi.h"
#include "unicode/ushape.h"
/**
* Function to be able to handle right-to-left text and Arabic chars properly.
*
* First: right-to-left (RTL) is stored 'logically' in almost all applications
* and so do we. This means that their text is stored from right to the
* left in memory and any non-RTL text (like numbers or English) are
* then stored from left-to-right. When we want to actually draw the
* text we need to reverse the RTL text in memory, which is what
* happens in ubidi_writeReordered.
* Second: Arabic characters "differ" based on their context. To draw the
* correct variant we pass it through u_shapeArabic. This function can
* add or remove some characters. This is the reason for the lastof
* so we know till where we can fill the output.
*
* Sadly enough these functions work with a custom character format, UChar,
* which isn't the same size as WChar. Because of that we need to transform
* our text first to UChars and then back to something we can use.
*
* To be able to truncate strings properly you must truncate before passing to
* this function. This way the logical begin of the string remains and the end
* gets chopped of instead of the other way around.
*
* The reshaping of Arabic characters might increase or decrease the width of
* the characters/string. So it might still overflow after truncation, though
* the chance is fairly slim as most characters get shorter instead of longer.
* @param buffer the buffer to read from/to
* @param lastof the end of the buffer
*/
static void HandleBiDiAndArabicShapes(char *buffer, const char *lastof)
{
UChar input_output[DRAW_STRING_BUFFER];
UChar intermediate[DRAW_STRING_BUFFER];
char *t = buffer;
size_t length = 0;
while (*t != '\0' && length < lengthof(input_output)) {
WChar tmp;
t += Utf8Decode(&tmp, t);
input_output[length++] = tmp;
}
input_output[length] = 0;
UErrorCode err = U_ZERO_ERROR;
UBiDi *para = ubidi_openSized(length, 0, &err);
if (para == NULL) return;
ubidi_setPara(para, input_output, length, UBIDI_DEFAULT_RTL, NULL, &err);
ubidi_writeReordered(para, intermediate, length, 0, &err);
length = u_shapeArabic(intermediate, length, input_output, lengthof(input_output), U_SHAPE_TEXT_DIRECTION_VISUAL_LTR | U_SHAPE_LETTERS_SHAPE, &err);
ubidi_close(para);
if (U_FAILURE(err)) return;
t = buffer;
for (size_t i = 0; i < length && t < (lastof - 4); i++) {
t += Utf8Encode(t, input_output[i]);
}
*t = '\0';
}
#endif /* WITH_ICU */
/** Truncate a given string to a maximum width if neccessary.
* If the string is truncated, add three dots ('...') to show this.
* @param *str string that is checked and possibly truncated
@@ -322,7 +391,8 @@ int DrawString(int x, int y, StringID str, uint16 color)
char buffer[DRAW_STRING_BUFFER];
GetString(buffer, str, lastof(buffer));
return DoDrawString(buffer, x, y, color);
HandleBiDiAndArabicShapes(buffer, lastof(buffer));
return ReallyDoDrawString(buffer, x, y, color);
}
/**
@@ -340,7 +410,8 @@ int DrawStringTruncated(int x, int y, StringID str, uint16 color, uint maxw)
{
char buffer[DRAW_STRING_BUFFER];
TruncateStringID(str, buffer, maxw, lastof(buffer));
return DoDrawString(buffer, x, y, color);
HandleBiDiAndArabicShapes(buffer, lastof(buffer));
return ReallyDoDrawString(buffer, x, y, color);
}
/**
@@ -359,8 +430,10 @@ int DrawStringRightAligned(int x, int y, StringID str, uint16 color)
int w;
GetString(buffer, str, lastof(buffer));
HandleBiDiAndArabicShapes(buffer, lastof(buffer));
w = GetStringBoundingBox(buffer).width;
DoDrawString(buffer, x - w, y, color);
ReallyDoDrawString(buffer, x - w, y, color);
return w;
}
@@ -379,7 +452,8 @@ void DrawStringRightAlignedTruncated(int x, int y, StringID str, uint16 color, u
char buffer[DRAW_STRING_BUFFER];
TruncateStringID(str, buffer, maxw, lastof(buffer));
DoDrawString(buffer, x - GetStringBoundingBox(buffer).width, y, color);
HandleBiDiAndArabicShapes(buffer, lastof(buffer));
ReallyDoDrawString(buffer, x - GetStringBoundingBox(buffer).width, y, color);
}
/**
@@ -412,9 +486,10 @@ int DrawStringCentered(int x, int y, StringID str, uint16 color)
int w;
GetString(buffer, str, lastof(buffer));
HandleBiDiAndArabicShapes(buffer, lastof(buffer));
w = GetStringBoundingBox(buffer).width;
DoDrawString(buffer, x - w / 2, y, color);
ReallyDoDrawString(buffer, x - w / 2, y, color);
return w;
}
@@ -433,8 +508,11 @@ int DrawStringCentered(int x, int y, StringID str, uint16 color)
int DrawStringCenteredTruncated(int xl, int xr, int y, StringID str, uint16 color)
{
char buffer[DRAW_STRING_BUFFER];
int w = TruncateStringID(str, buffer, xr - xl, lastof(buffer));
return DoDrawString(buffer, (xl + xr - w) / 2, y, color);
TruncateStringID(str, buffer, xr - xl, lastof(buffer));
HandleBiDiAndArabicShapes(buffer, lastof(buffer));
int w = GetStringBoundingBox(buffer).width;
return ReallyDoDrawString(buffer, (xl + xr - w) / 2, y, color);
}
/**
@@ -449,8 +527,12 @@ int DrawStringCenteredTruncated(int xl, int xr, int y, StringID str, uint16 colo
*/
int DoDrawStringCentered(int x, int y, const char *str, uint16 color)
{
int w = GetStringBoundingBox(str).width;
DoDrawString(str, x - w / 2, y, color);
char buffer[DRAW_STRING_BUFFER];
strecpy(buffer, str, lastof(buffer));
HandleBiDiAndArabicShapes(buffer, lastof(buffer));
int w = GetStringBoundingBox(buffer).width;
ReallyDoDrawString(buffer, x - w / 2, y, color);
return w;
}
@@ -613,7 +695,7 @@ void DrawStringMultiCenter(int x, int y, StringID str, int maxw)
{
char buffer[DRAW_STRING_BUFFER];
uint32 tmp;
int num, w, mt;
int num, mt;
const char *src;
WChar c;
@@ -629,8 +711,11 @@ void DrawStringMultiCenter(int x, int y, StringID str, int maxw)
src = buffer;
for (;;) {
w = GetStringBoundingBox(src).width;
DoDrawString(src, x - (w >> 1), y, 0xFE, true);
char buf2[DRAW_STRING_BUFFER];
strecpy(buf2, src, lastof(buf2));
HandleBiDiAndArabicShapes(buf2, lastof(buf2));
int w = GetStringBoundingBox(buf2).width;
ReallyDoDrawString(buf2, x - (w >> 1), y, 0xFE, true);
_cur_fontsize = _last_fontsize;
for (;;) {
@@ -680,7 +765,10 @@ uint DrawStringMultiLine(int x, int y, StringID str, int maxw, int maxh)
src = buffer;
for (;;) {
DoDrawString(src, x, y, 0xFE, true);
char buf2[DRAW_STRING_BUFFER];
strecpy(buf2, src, lastof(buf2));
HandleBiDiAndArabicShapes(buf2, lastof(buf2));
ReallyDoDrawString(buf2, x, y, 0xFE, true);
_cur_fontsize = _last_fontsize;
for (;;) {
@@ -767,7 +855,7 @@ void DrawCharCentered(WChar c, int x, int y, uint16 real_color)
/** Draw a string at the given coordinates with the given colour.
* While drawing the string, parse it in case some formatting is specified,
* like new colour, new size or even positionning.
* @param string The string to draw
* @param string The string to draw. This is not yet bidi reordered.
* @param x Offset from left side of the screen
* @param y Offset from top side of the screen
* @param real_colour Colour of the string, see _string_colormap in
@@ -782,6 +870,32 @@ void DrawCharCentered(WChar c, int x, int y, uint16 real_color)
* If nothing is drawn, the originally passed x-coordinate is returned
*/
int DoDrawString(const char *string, int x, int y, uint16 real_colour, bool parse_string_also_when_clipped)
{
char buffer[DRAW_STRING_BUFFER];
strecpy(buffer, string, lastof(buffer));
HandleBiDiAndArabicShapes(buffer, lastof(buffer));
return ReallyDoDrawString(buffer, x, y, real_colour, parse_string_also_when_clipped);
}
/** Draw a string at the given coordinates with the given colour.
* While drawing the string, parse it in case some formatting is specified,
* like new colour, new size or even positionning.
* @param string The string to draw. This is already bidi reordered.
* @param x Offset from left side of the screen
* @param y Offset from top side of the screen
* @param real_colour Colour of the string, see _string_colormap in
* table/palettes.h or docs/ottd-colourtext-palette.png or the enum TextColour in gfx_type.h
* @param parse_string_also_when_clipped
* By default, always test the available space where to draw the string.
* When in multipline drawing, it would already be done,
* so no need to re-perform the same kind (more or less) of verifications.
* It's not only an optimisation, it's also a way to ensures the string will be parsed
* (as there are certain side effects on global variables, which are important for the next line)
* @return the x-coordinates where the drawing has finished.
* If nothing is drawn, the originally passed x-coordinate is returned
*/
static int ReallyDoDrawString(const char *string, int x, int y, uint16 real_colour, bool parse_string_also_when_clipped)
{
DrawPixelInfo *dpi = _cur_dpi;
FontSize size = _cur_fontsize;