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authorrubidium <rubidium@openttd.org>2008-10-17 17:14:09 +0000
committerrubidium <rubidium@openttd.org>2008-10-17 17:14:09 +0000
commitae0715e8c345046ef23fdd41dbc57a91b5f574f1 (patch)
treeaee965f46359694e98f85960c6ccc65756a89261 /src
parentb6ca10b05a316b801908cde1fe7de2f4236f6fb8 (diff)
downloadopenttd-ae0715e8c345046ef23fdd41dbc57a91b5f574f1.tar.xz
(svn r14479) -Add: initial (optional) support for handling bidirectional scripts and connecting Arabic characters.
Diffstat (limited to 'src')
-rw-r--r--src/gfx.cpp142
1 files changed, 128 insertions, 14 deletions
diff --git a/src/gfx.cpp b/src/gfx.cpp
index 9f896be32..ffe9e2387 100644
--- a/src/gfx.cpp
+++ b/src/gfx.cpp
@@ -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
@@ -783,6 +871,32 @@ void DrawCharCentered(WChar c, int x, int y, uint16 real_color)
*/
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;
WChar c;