diff options
Diffstat (limited to 'source/blender/blenlib/intern/math_color_blend_inline.c')
| -rw-r--r-- | source/blender/blenlib/intern/math_color_blend_inline.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/source/blender/blenlib/intern/math_color_blend_inline.c b/source/blender/blenlib/intern/math_color_blend_inline.c index 121750fe919..52947fcee08 100644 --- a/source/blender/blenlib/intern/math_color_blend_inline.c +++ b/source/blender/blenlib/intern/math_color_blend_inline.c @@ -242,6 +242,28 @@ MINLINE void blend_color_add_alpha_byte(unsigned char dst[4], const unsigned cha } } +MINLINE void blend_color_interpolate_byte(unsigned char dst[4], const unsigned char src1[4], const unsigned char src2[4], float ft) +{ + /* do color interpolation, but in premultiplied space so that RGB colors + * from zero alpha regions have no influence */ + const int t = (int)(255 * ft); + const int mt = 255 - t; + int tmp = (mt * src1[3] + t * src2[3]); + + if (tmp > 0) { + dst[0] = divide_round_i(mt * src1[0] * src1[3] + t * src2[0] * src2[3], tmp); + dst[1] = divide_round_i(mt * src1[1] * src1[3] + t * src2[1] * src2[3], tmp); + dst[2] = divide_round_i(mt * src1[2] * src1[3] + t * src2[2] * src2[3], tmp); + dst[3] = divide_round_i(tmp, 255); + } + else { + dst[0] = src1[0]; + dst[1] = src1[1]; + dst[2] = src1[2]; + dst[3] = src1[3]; + } +} + /* premultiplied alpha float blending modes */ MINLINE void blend_color_mix_float(float dst[4], const float src1[4], const float src2[4]) @@ -420,4 +442,15 @@ MINLINE void blend_color_add_alpha_float(float dst[4], const float src1[4], cons } } +MINLINE void blend_color_interpolate_float(float dst[4], const float src1[4], const float src2[4], float t) +{ + /* interpolation, colors are premultiplied so it goes fine */ + float mt = 1.0f - t; + + dst[0] = mt * src1[0] + t * src2[0]; + dst[1] = mt * src1[1] + t * src2[1]; + dst[2] = mt * src1[2] + t * src2[2]; + dst[3] = mt * src1[3] + t * src2[3]; +} + #endif /* __MATH_COLOR_BLEND_INLINE_C__ */ |