Alternative library and kernel for add-in development on fx-9860G and fx-CG50 under Linux.
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gint/src/render/topti.c

112 lines
2.7 KiB

#include <gint/defs/types.h>
#include <gint/display.h>
#include <display/common.h>
/* TODO: These parameters will eventually be specified by the font */
#define CHAR_SPACING 1
#define PROP_SPACING 5
/* dfont(): Set the default font for text rendering */
GSECTION(".pretext")
void dfont(font_t const * font)
{
topti_font = font ? font : gint_default_font;
}
/* charset_size(): Number of elements in each character set */
GSECTION(".pretext")
int charset_size(enum topti_charset set)
{
int size[] = { 10, 26, 52, 62, 95, 128 };
return (uint)set < 6 ? size[set] : -1;
}
/* charset_decode(): Translate ASCII into reduced character sets */
GSECTION(".pretext")
int charset_decode(enum topti_charset set, uint c)
{
int x, y;
switch(set)
{
case charset_numeric:
x = c - '0';
return (x < 10) ? x : -1;
case charset_upper:
x = (c - 'A') & ~0x20;
return (x < 26) ? x : -1;
case charset_alnum:
x = c - '0';
if(x < 10) return x;
/* Intentional fallthrough */
case charset_alpha:
y = c & 0x20;
x = (c ^ y) - 'A';
/* Turn 32 into 26 and leave 0 as 0 */
y = y - (y >> 3) - (y >> 4);
return (x < 26) ? (x + y) : -1;
case charset_print:
x = c - 0x20;
return (x < 0x5f) ? x : -1;
case charset_ascii:
return c;
}
return -1;
}
/* topti_offset(): Use a font index to find the location of a glyph */
GSECTION(".pretext")
int topti_offset(font_t const *f, uint glyph)
{
/* Non-proportional fonts don't need an index */
if(!f->prop) return glyph * f->storage_size;
uint8_t const *width = f->sized_data;
/* The index gives us the position of all glyphs whose IDs are mutiples
of 8. Start with a close one and iterate from there. */
uint g = glyph & ~0x7;
int offset = f->index[g >> 3];
/* Traverse the width array (which is in bits) while converting to
longword size */
while(g < glyph) offset += (width[g++] * f->data_height + 31) >> 5;
return offset;
}
/* dsize() - get the width and height of rendered text */
void dsize(const char *str, font_t const * f, int *w, int *h)
{
if(!f) f = topti_font;
if(h) *h = f->line_height;
if(!w) return;
/* Width for monospaced fonts is easy, unfortunately we still need to
compute the length of [str]. Critical applications might do the
product themselves to avoid this cost. */
if(!f->prop)
{
int length = 0;
while(*str++) length++;
*w = (f->width + CHAR_SPACING) * length - CHAR_SPACING;
return;
}
/* For proportional fonts, fetch the width of each individual glyphs */
int width = 0, c;
while((c = *str++))
{
if(c == ' ')
{
width += PROP_SPACING + CHAR_SPACING;
continue;
}
int glyph = charset_decode(f->charset, c);
if(glyph > 0) width += f->sized_data[glyph] + CHAR_SPACING;
}
*w = width - CHAR_SPACING;
}