diff options
| -rw-r--r-- | bin/pngo.c | 119 |
1 files changed, 53 insertions, 66 deletions
diff --git a/bin/pngo.c b/bin/pngo.c index 37fd6af7..993593f4 100644 --- a/bin/pngo.c +++ b/bin/pngo.c @@ -113,7 +113,6 @@ enum PACKED Color { GRAYSCALE_ALPHA = 4, TRUECOLOR_ALPHA = 6 }; -#define ALPHA (0x04) static struct PACKED { uint32_t width; @@ -200,6 +199,22 @@ static struct { uint8_t entries[256][3]; } palette; +static uint16_t paletteIndex(const uint8_t *rgb) { + uint16_t i; + for (i = 0; i < palette.len; ++i) { + if (0 == memcmp(palette.entries[i], rgb, 3)) break; + } + return i; +} + +static bool paletteAdd(const uint8_t *rgb) { + uint16_t i = paletteIndex(rgb); + if (i < palette.len) return true; + if (i == 256) return false; + memcpy(palette.entries[palette.len++], rgb, 3); + return true; +} + static void readPalette(void) { struct Chunk chunk; for (;;) { @@ -231,10 +246,12 @@ static void writePalette(void) { static uint8_t *data; -static void readData(void) { +static void allocData(void) { data = malloc(dataSize()); if (!data) err(EX_OSERR, "malloc(%zu)", dataSize()); +} +static void readData(void) { struct z_stream_s stream = { .next_out = data, .avail_out = dataSize() }; int error = inflateInit(&stream); if (error != Z_OK) errx(EX_SOFTWARE, "%s: inflateInit: %s", path, stream.msg); @@ -345,10 +362,12 @@ static struct { uint8_t *data; } *lines; -static void scanlines(void) { +static void allocLines(void) { lines = calloc(header.height, sizeof(*lines)); if (!lines) err(EX_OSERR, "calloc(%u, %zu)", header.height, sizeof(*lines)); +} +static void scanlines(void) { size_t stride = 1 + lineSize(); for (uint32_t y = 0; y < header.height; ++y) { lines[y].type = &data[y * stride]; @@ -399,113 +418,78 @@ static void filterData(void) { } static void discardAlpha(void) { - if (!(header.color & ALPHA)) return; + if (header.color != GRAYSCALE_ALPHA && header.color != TRUECOLOR_ALPHA) return; size_t sampleSize = header.depth / 8; - size_t pixelSize = 4 * sampleSize; + size_t pixelSize = sampleSize * (header.color == GRAYSCALE_ALPHA ? 2 : 4); + size_t colorSize = pixelSize - sampleSize; for (uint32_t y = 0; y < header.height; ++y) { for (uint32_t x = 0; x < header.width; ++x) { for (size_t i = 0; i < sampleSize; ++i) { - if (lines[y].data[x * pixelSize + 3 * sampleSize + i] != 0xFF) return; + if (lines[y].data[x * pixelSize + colorSize + i] != 0xFF) return; } } } + header.color = (header.color == GRAYSCALE_ALPHA) ? GRAYSCALE : TRUECOLOR; uint8_t *ptr = data; for (uint32_t y = 0; y < header.height; ++y) { - uint8_t *type = ptr++; - uint8_t *data = ptr; - *type = *lines[y].type; + *ptr++ = *lines[y].type; for (uint32_t x = 0; x < header.width; ++x) { - memcpy(ptr, &lines[y].data[x * pixelSize], 3 * sampleSize); - ptr += 3 * sampleSize; + memcpy(ptr, &lines[y].data[x * pixelSize], colorSize); + ptr += colorSize; } - lines[y].type = type; - lines[y].data = data; } - header.color &= ~ALPHA; + scanlines(); } static void discardColor(void) { if (header.color != TRUECOLOR && header.color != TRUECOLOR_ALPHA) return; size_t sampleSize = header.depth / 8; - size_t pixelSize = ((header.color & ALPHA) ? 4 : 3) * sampleSize; + size_t pixelSize = sampleSize * (header.color == TRUECOLOR ? 3 : 4); for (uint32_t y = 0; y < header.height; ++y) { for (uint32_t x = 0; x < header.width; ++x) { - if ( - 0 != memcmp( - &lines[y].data[x * pixelSize], - &lines[y].data[x * pixelSize + 1 * sampleSize], - sampleSize - ) - ) return; - if ( - 0 != memcmp( - &lines[y].data[x * pixelSize + 1 * sampleSize], - &lines[y].data[x * pixelSize + 2 * sampleSize], - sampleSize - ) - ) return; + uint8_t *r = &lines[y].data[x * pixelSize]; + uint8_t *g = r + sampleSize; + uint8_t *b = g + sampleSize; + if (0 != memcmp(r, g, sampleSize)) return; + if (0 != memcmp(g, b, sampleSize)) return; } } + header.color = (header.color == TRUECOLOR) ? GRAYSCALE : GRAYSCALE_ALPHA; uint8_t *ptr = data; for (uint32_t y = 0; y < header.height; ++y) { - uint8_t *type = ptr++; - uint8_t *data = ptr; - *type = *lines[y].type; + *ptr++ = *lines[y].type; for (uint32_t x = 0; x < header.width; ++x) { - memcpy(ptr, &lines[y].data[x * pixelSize], sampleSize); + uint8_t *pixel = &lines[y].data[x * pixelSize]; + memcpy(ptr, pixel, sampleSize); ptr += sampleSize; - if (header.color & ALPHA) { - memcpy( - ptr, - &lines[y].data[x * pixelSize + 3 * sampleSize], - sampleSize - ); + if (header.color == TRUECOLOR_ALPHA) { + memcpy(ptr, pixel + 3 * sampleSize, sampleSize); ptr += sampleSize; } } - lines[y].type = type; - lines[y].data = data; } - header.color &= ~TRUECOLOR; + scanlines(); } static void indexColor(void) { if (header.color != TRUECOLOR || header.depth != 8) return; for (uint32_t y = 0; y < header.height; ++y) { for (uint32_t x = 0; x < header.width; ++x) { - uint32_t i; - for (i = 0; i < palette.len; ++i) { - if (0 == memcmp(palette.entries[i], &lines[y].data[x * 3], 3)) { - break; - } - } - if (i < palette.len) continue; - if (palette.len == 256) return; - memcpy(palette.entries[i], &lines[y].data[x * 3], 3); - palette.len++; + if (!paletteAdd(&lines[y].data[x * 3])) return; } } + header.color = INDEXED; uint8_t *ptr = data; for (uint32_t y = 0; y < header.height; ++y) { - uint8_t *type = ptr++; - uint8_t *data = ptr; - *type = *lines[y].type; + *ptr++ = *lines[y].type; for (uint32_t x = 0; x < header.width; ++x) { - uint32_t i; - for (i = 0; i < palette.len; ++i) { - if (0 == memcmp(palette.entries[i], &lines[y].data[x * 3], 3)) { - break; - } - } - *ptr++ = i; + *ptr++ = paletteIndex(&lines[y].data[x * 3]); } - lines[y].type = type; - lines[y].data = data; } - header.color = INDEXED; + scanlines(); } static void optimize(const char *inPath, const char *outPath) { @@ -527,13 +511,16 @@ static void optimize(const char *inPath, const char *outPath) { ); } if (header.color == INDEXED) readPalette(); + allocData(); readData(); int error = fclose(file); if (error) err(EX_IOERR, "%s", path); + allocLines(); scanlines(); reconData(); + discardAlpha(); discardColor(); indexColor(); @@ -553,8 +540,8 @@ static void optimize(const char *inPath, const char *outPath) { writeHeader(); if (header.color == INDEXED) writePalette(); writeData(); - writeEnd(); free(data); + writeEnd(); error = fclose(file); if (error) err(EX_IOERR, "%s", path); |