diff options
Diffstat (limited to 'source/fitz/output-tga.c')
| -rw-r--r-- | source/fitz/output-tga.c | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/source/fitz/output-tga.c b/source/fitz/output-tga.c index 3bee3640..0e7a213c 100644 --- a/source/fitz/output-tga.c +++ b/source/fitz/output-tga.c @@ -13,19 +13,22 @@ typedef struct { static inline void tga_put_pixel(fz_context *ctx, fz_output *out, const unsigned char *data, int n, int is_bgr) { + int a, inva; switch(n) { case 4: /* RGBA or BGRA */ + a = data[3]; + inva = a ? 256 * 255 / a : 0; if (!is_bgr) { - fz_write_byte(ctx, out, data[2]); - fz_write_byte(ctx, out, data[1]); - fz_write_byte(ctx, out, data[0]); + fz_write_byte(ctx, out, (data[2] * inva + 128)>>8); + fz_write_byte(ctx, out, (data[1] * inva + 128)>>8); + fz_write_byte(ctx, out, (data[0] * inva + 128)>>8); } else { - fz_write_byte(ctx, out, data[0]); - fz_write_byte(ctx, out, data[1]); - fz_write_byte(ctx, out, data[2]); + fz_write_byte(ctx, out, (data[0] * inva + 128)>>8); + fz_write_byte(ctx, out, (data[1] * inva + 128)>>8); + fz_write_byte(ctx, out, (data[2] * inva + 128)>>8); } - fz_write_byte(ctx, out, data[3]); + fz_write_byte(ctx, out, a); break; case 3: /* RGB or BGR */ if (!is_bgr) { @@ -39,10 +42,13 @@ static inline void tga_put_pixel(fz_context *ctx, fz_output *out, const unsigned } break; case 2: /* GA */ - fz_write_byte(ctx, out, data[0]); - fz_write_byte(ctx, out, data[0]); - fz_write_byte(ctx, out, data[0]); - fz_write_byte(ctx, out, data[1]); + a = data[1]; + inva = a ? 256 * 255 / a : 0; + inva = (data[0] * inva + 128)>>8; + fz_write_byte(ctx, out, inva); + fz_write_byte(ctx, out, inva); + fz_write_byte(ctx, out, inva); + fz_write_byte(ctx, out, a); break; case 1: /* G */ fz_write_byte(ctx, out, data[0]); |