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| author | June McEnroe <june@causal.agency> | 2018-02-06 20:18:38 -0500 |
|---|---|---|
| committer | June McEnroe <june@causal.agency> | 2018-02-06 20:18:38 -0500 |
| commit | 45a9d3baeeb5424d9d23044fb9661dce286fc328 (patch) | |
| tree | 4387ca4598f030c1a2ba14aca36be244b54d1ee4 /bin | |
| parent | Rename gfxx space indexed and add palette sampling (diff) | |
| download | src-45a9d3baeeb5424d9d23044fb9661dce286fc328.tar.gz src-45a9d3baeeb5424d9d23044fb9661dce286fc328.zip | |
Replace gfxx SCALE macro with interp function
Short-circuits for b = 8.
Diffstat (limited to '')
| -rw-r--r-- | bin/gfxx.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/bin/gfxx.c b/bin/gfxx.c index 6ad57e0a..184699b8 100644 --- a/bin/gfxx.c +++ b/bin/gfxx.c @@ -29,7 +29,6 @@ #define RGB(r,g,b) ((uint32_t)(r) << 16 | (uint32_t)(g) << 8 | (uint32_t)(b)) #define GRAY(n) RGB(n, n, n) #define MASK(b) ((1 << (b)) - 1) -#define SCALE(b,n) ((b) ? (uint8_t)(255 * (uint32_t)(n) / MASK(b)) : 0) static enum { COLOR_INDEXED, @@ -201,6 +200,12 @@ static void put(const struct Iter *it, uint32_t p) { } } +static uint8_t interp(uint8_t b, uint32_t n) { + if (b == 8) return n; + if (b == 0) return 0; + return n * MASK(8) / MASK(b); +} + static uint32_t interpolate(uint32_t n) { uint32_t r, g, b; if (bitOrder == ENDIAN_LITTLE) { @@ -212,7 +217,7 @@ static uint32_t interpolate(uint32_t n) { g = (n >>= bits[1]) & MASK(bits[2]); b = (n >>= bits[2]) & MASK(bits[3]); } - return RGB(SCALE(bits[1], r), SCALE(bits[2], g), SCALE(bits[3], b)); + return RGB(interp(bits[1], r), interp(bits[2], g), interp(bits[3], b)); } static void drawBits(struct Iter *it) { @@ -227,7 +232,7 @@ static void drawBits(struct Iter *it) { if (space == COLOR_INDEXED) { put(it, palette[n]); } else if (space == COLOR_GRAYSCALE) { - put(it, GRAY(SCALE(BITS_COLOR, n))); + put(it, GRAY(interp(BITS_COLOR, n & MASK(BITS_COLOR)))); } else if (space == COLOR_RGB) { put(it, interpolate(n)); } @@ -247,7 +252,7 @@ static void drawBytes(struct Iter *it) { if (space == COLOR_INDEXED) { put(it, palette[n & 0xFF]); } else if (space == COLOR_GRAYSCALE) { - put(it, GRAY(SCALE(BITS_COLOR, n & MASK(BITS_COLOR)))); + put(it, GRAY(interp(BITS_COLOR, n & MASK(BITS_COLOR)))); } else if (space == COLOR_RGB) { put(it, interpolate(n)); } |