sampling textures in game.

1 files changed, 22 insertions, 0 deletions

diff --git a/testbc1.c b/testbc1.c
index 2b9aab4..8475bb2 100644
--- a/testbc1.c
+++ b/testbc1.c
@@ -13,6 +13,8 @@ void lerp(vec3* d, const vec3* a, const vec3* b, float t) {
 	d->b = a->b + t * (b->b - a->b);
 }
 
+#define use_float_sample 0
+#if use_float_sample
 Colour get_pixel(unsigned* data, int x, int y, int w) {
 	vec3 start, end, col;
 	float t;
@@ -35,6 +37,26 @@ Colour get_pixel(unsigned* data, int x, int y, int w) {
 	r.b = (int)(col.b * 255.0f);
 	return r;
 }
+#else
+Colour get_pixel(unsigned* data, int x, int y, int w) {
+	Colour r;
+	int s[3];
+	int i;
+	int coord = ((x >> 2) + (y >> 2) * (w >> 2)) << 1;
+	unsigned pal = data[coord];
+	unsigned ind = data[coord + 1];
+	s[0] = (pal & (31 << 27)) >> 24;
+	s[1] = (pal & (63 << 21)) >> 19;
+	s[2] = (pal & (31 << 16)) >> 13;
+	i = ((x & 3) + ((y & 3) << 2)) << 1;
+	i = (ind & (3 << i)) >> i;
+	r.r = s[0] + (i * ((int)((pal & (31 << 11)) >> 8) - s[0]) / 3);
+	r.g = s[1] + (i * ((int)((pal & (63 << 5))  >> 3) - s[1]) / 3);
+	r.b = s[2] + (i * ((int)((pal & (31     ))  << 3) - s[2]) / 3);
+	r.a = 0xff;
+	return r;
+}
+#endif
 
 int main(int argc, const char** argv) {
 	FILE* infile, * outfile;