From e40b7c1a295e63984ec9802a5afafba3367eb0fb Mon Sep 17 00:00:00 2001
From: King_DuckZ <king_duckz@gmx.com>
Date: Fri, 14 Sep 2018 19:35:29 +0100
Subject: [PATCH] Fix 8bit to float to 8bit conversion

---
 src/gui/icon_fetch.cpp | 42 ++++++++++++++++++++++++++----------------
 1 file changed, 26 insertions(+), 16 deletions(-)

diff --git a/src/gui/icon_fetch.cpp b/src/gui/icon_fetch.cpp
index 6cb43a7..71528b7 100644
--- a/src/gui/icon_fetch.cpp
+++ b/src/gui/icon_fetch.cpp
@@ -49,6 +49,10 @@ namespace {
 
 	[[gnu::pure]]
 	float to_srgb (float l) {
+		if (l <= 0.00313066844250063f)
+			return l * 12.92f;
+		else
+			return 1.055f * std::pow(l, 1.0f / 2.4f) - 0.055f;
 	}
 
 	void srgb_to_linear (std::vector<float>& data, int, int) {
@@ -56,17 +60,16 @@ namespace {
 	}
 
 	void linear_to_srgb (std::vector<float>& data, int w, int h) {
-		assert(false);
+		std::transform(data.begin(), data.end(), data.begin(), &to_srgb);
 	}
 
 	std::vector<float> bilinear_resize (int in_w, int in_h, const std::vector<float>& data, int out_w, int out_h) {
-		assert(false);
-		return std::vector<float>();
+		return data;
 	}
 
 	std::vector<float> rgb4_to_float (const std::vector<char>& data, const std::vector<uint8_t>& palette, int w, int h) {
 		assert(w * h);
-		std::vector<float> retval(w * h);
+		std::vector<float> retval(w * h * 3);
 		const int scanl_sz = scanline_size(w, 4);
 
 		std::vector<float> float_palette;
@@ -82,10 +85,10 @@ namespace {
 			const int row = y * scanl_sz;
 			for (int x = 0; x < w / 2; ++x) {
 				const uint8_t curr = data[row + x];
-				const int dst_index_a = y * scanl_sz + x * 2 * 3;
+				const int dst_index_a = y * (w * 3) + x * 2 * 3;
 				const int dst_index_b = dst_index_a + 3;
-				const int src_index_a = (curr bitand 0x0f) * 4;
-				const int src_index_b = ((curr bitand 0xf0) >> 4) * 4;
+				const int src_index_b = (curr bitand 0x0f) * 4;
+				const int src_index_a = ((curr bitand 0xf0) >> 4) * 4;
 
 				retval[dst_index_a + 0] = float_palette[src_index_a + 0];
 				retval[dst_index_a + 1] = float_palette[src_index_a + 1];
@@ -98,11 +101,17 @@ namespace {
 		return retval;
 	}
 
-	std::vector<char> float_to_rgb24 (const std::vector<float>& data) {
-		std::vector<char> retval;
-		retval.reserve(data.size());
-		for (auto f : data) {
-			retval.push_back(static_cast<char>(static_cast<uint8_t>(f * 255.0f)));
+	std::vector<char> float_to_rgb24 (const std::vector<float>& data, int w, int h) {
+		const int scanl_sz = scanline_size(w, 24);
+		std::vector<char> retval(scanl_sz * h);
+		assert(retval.size() >= data.size());
+
+		for (int y = 0; y < h; ++y) {
+			for (int x = 0; x < w; ++x) {
+				for (int c = 0; c < 3; ++c) {
+					retval[y * scanl_sz + x * 3 + c] = static_cast<char>(static_cast<uint8_t>(data[y * scanl_sz + x * 3 + c] * 255.0f));
+				}
+			}
 		}
 		return retval;
 	}
@@ -163,10 +172,11 @@ std::vector<std::vector<char>> icon_fetch (const ConstBlock& block, int width, i
 		std::vector<char> resized_rgb;
 		if (scale) {
 			std::vector<float> float_data = rgb4_to_float(orig_rgb, palette, in_width, in_height);
-			srgb_to_linear(float_data, in_width, in_height);
-			auto float_resized_rgb = bilinear_resize(in_width, in_height, float_data, width, height);
-			linear_to_srgb(float_resized_rgb, width, height);
-			resized_rgb = float_to_rgb24(float_resized_rgb);
+			//srgb_to_linear(float_data, in_width, in_height);
+			//auto float_resized_rgb = bilinear_resize(in_width, in_height, float_data, width, height);
+			//linear_to_srgb(float_resized_rgb, width, height);
+			//resized_rgb = float_to_rgb24(float_resized_rgb, width, height);
+			resized_rgb = float_to_rgb24(float_data, width, height);
 		}
 		else {
 			std::swap(resized_rgb, orig_rgb);