From e3bb3ba644aad61c50d10d4e7b750208efb176c6 Mon Sep 17 00:00:00 2001 From: Nicolas VIVIEN Date: Mon, 31 Jul 2023 13:44:22 +0200 Subject: [PATCH] Fix shadow text rendering on alpha buffer Signed-off-by: Nicolas VIVIEN --- src/libOpenImageIO/imagebufalgo_draw.cpp | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/src/libOpenImageIO/imagebufalgo_draw.cpp b/src/libOpenImageIO/imagebufalgo_draw.cpp index a88aacd182..184aa3360c 100644 --- a/src/libOpenImageIO/imagebufalgo_draw.cpp +++ b/src/libOpenImageIO/imagebufalgo_draw.cpp @@ -1078,7 +1078,9 @@ ImageBufAlgo::render_text(ImageBuf& R, int x, int y, string_view text, // If the buffer doesn't have an alpha, but the text color passed // has 4 values, assume the last value is supposed to be alpha. textalpha = textcolor[3]; - } + alpha_channel = 3; + } else + alpha_channel = -1; // Convert the UTF to 32 bit unicode std::vector utext; @@ -1162,8 +1164,14 @@ ImageBufAlgo::render_text(ImageBuf& R, int x, int y, string_view text, float val = t[0]; float alpha = a[0] * textalpha; R.getpixel(r.x(), r.y(), pixelcolor); - for (int c = 0; c < nchannels; ++c) - pixelcolor[c] = val * textcolor[c] + (1.0f - alpha) * pixelcolor[c]; + if (alpha == 0.0) + continue; + for (int c = 0; c < nchannels; ++c) { + if (c == alpha_channel) + pixelcolor[c] = alpha + (1.0f - alpha) * pixelcolor[c]; + else + pixelcolor[c] = (val * alpha * textcolor[c]) + (1.0f - alpha) * pixelcolor[c]; + } R.setpixel(r.x(), r.y(), pixelcolor); }