From bb0592ade8e027403d83ad8a073226631a0c3f74 Mon Sep 17 00:00:00 2001
From: Gary Talent <gary@drinkingtea.net>
Date: Wed, 16 Feb 2022 02:11:27 -0600
Subject: [PATCH] [nostalgia/core] Fix NostalgiaGraphic::setPixel

---
 src/nostalgia/core/gfx.hpp | 39 ++++++++++++++++++++++++++++----------
 1 file changed, 29 insertions(+), 10 deletions(-)

diff --git a/src/nostalgia/core/gfx.hpp b/src/nostalgia/core/gfx.hpp
index 882d62990..8256ef526 100644
--- a/src/nostalgia/core/gfx.hpp
+++ b/src/nostalgia/core/gfx.hpp
@@ -47,9 +47,8 @@ struct NostalgiaGraphic {
 	ox::Vector<uint8_t> pixels;
 
 	[[nodiscard]]
-	constexpr auto getPixel4Bpp(const geo::Point &pt) const noexcept {
+	constexpr auto getPixel4Bpp(std::size_t idx) const noexcept {
 		oxAssert(bpp == 4, "NostalgiaGraphic::getPixel4Bpp: wrong bpp");
-		const auto idx = ptToIdx(pt, this->columns);
 		if (idx & 1) {
 			return this->pixels[idx / 2];
 		} else {
@@ -58,30 +57,50 @@ struct NostalgiaGraphic {
 	}
 
 	[[nodiscard]]
-	constexpr auto getPixel8Bpp(const geo::Point &pt) const noexcept {
+	constexpr auto getPixel8Bpp(std::size_t idx) const noexcept {
 		oxAssert(bpp == 8, "NostalgiaGraphic::getPixel8Bpp: wrong bpp");
-		const auto idx = ptToIdx(pt, this->columns);
 		return this->pixels[idx];
 	}
 
 	[[nodiscard]]
-	constexpr auto getPixel(const geo::Point &pt) const noexcept {
+	constexpr auto getPixel(std::size_t idx) const noexcept {
 		if (this->bpp == 4) {
-			return getPixel4Bpp(pt);
+			return getPixel4Bpp(idx);
 		} else {
-			return getPixel8Bpp(pt);
+			return getPixel8Bpp(idx);
 		}
 	}
 
+	[[nodiscard]]
+	constexpr auto getPixel4Bpp(const geo::Point &pt) const noexcept {
+		oxAssert(bpp == 4, "NostalgiaGraphic::getPixel4Bpp: wrong bpp");
+		const auto idx = ptToIdx(pt, this->columns);
+		return getPixel4Bpp(idx);
+	}
+
+	[[nodiscard]]
+	constexpr auto getPixel8Bpp(const geo::Point &pt) const noexcept {
+		oxAssert(bpp == 8, "NostalgiaGraphic::getPixel8Bpp: wrong bpp");
+		const auto idx = ptToIdx(pt, this->columns);
+		return getPixel8Bpp(idx);
+	}
+
+	[[nodiscard]]
+	constexpr auto getPixel(const geo::Point &pt) const noexcept {
+		const auto idx = ptToIdx(pt, this->columns);
+		return getPixel(idx);
+	}
+
 	constexpr void setPixel(uint64_t idx, uint8_t palIdx) noexcept {
+		 auto &pixel = this->pixels[idx / 2];
 		if (bpp == 4) {
 			if (idx & 1) {
-				pixels[idx / 2] &= 0b0000'1111 | (palIdx << 4);
+				pixel = (pixel & 0b0000'1111) | (palIdx << 4);
 			} else {
-				pixels[idx / 2] &= 0b1111'0000 | (palIdx);
+				pixel = (pixel & 0b1111'0000) | (palIdx);
 			}
 		} else {
-			this->pixels[idx] = palIdx;
+			pixel = palIdx;
 		}
 	}