blues/decode.c

70 lines
1.6 KiB
C

#include "decode.h"
void decode_ega_spr(const uint8_t *src, int src_pitch, int w, int h, uint8_t *dst, int dst_pitch, int dst_x, int dst_y) {
assert((src_pitch & 7) == 0);
src_pitch /= 8;
assert((w & 7) == 0);
w /= 8;
dst += dst_y * dst_pitch + dst_x;
const int bitplane_size = w * h;
for (int y = 0; y < h; ++y) {
for (int x = 0; x < w; ++x) {
for (int i = 0; i < 8; ++i) {
int color = 0;
const int mask = 1 << (7 - i);
for (int bit = 0; bit < 4; ++bit) {
if (src[bit * bitplane_size] & mask) {
color |= 1 << (3 - bit);
}
}
dst[x * 8 + i] = color;
}
++src;
}
src += src_pitch - w;
dst += dst_pitch;
}
}
void decode_amiga_planar8(const uint8_t *src, int w, int h, int depth, uint8_t *dst, int dst_pitch, int dst_x, int dst_y) {
dst += dst_y * dst_pitch + dst_x;
const int plane_size = w * h;
for (int y = 0; y < h; ++y) {
for (int x = 0; x < w; ++x) {
for (int i = 0; i < 8; ++i) {
int color = 0;
const int mask = 1 << (7 - i);
for (int bit = 0; bit < depth; ++bit) {
if (src[bit * plane_size] & mask) {
color |= 1 << bit;
}
}
dst[x * 8 + i] = color;
}
++src;
}
dst += dst_pitch;
}
}
void decode_amiga_blk(const uint8_t *src, uint8_t *dst, int dst_pitch) {
uint16_t data[4];
for (int y = 0; y < 16; ++y) {
for (int p = 0; p < 4; ++p) {
data[p] = READ_BE_UINT16(src); src += 2;
}
for (int b = 0; b < 16; ++b) {
const int mask = 1 << (15 - b);
uint8_t color = 0;
for (int p = 0; p < 4; ++p) {
if (data[p] & mask) {
color |= 1 << p;
}
}
dst[b] = color;
}
dst += dst_pitch;
}
}