Add a helper for loading PCX as CEL from path

Source/CMakeLists.txt

@@ -84,6 +84,7 @@ set(libdevilutionx_SRCS
   engine/demomode.cpp
   engine/direction.cpp
   engine/load_cel.cpp
+  engine/load_pcx_as_cel.cpp
   engine/random.cpp
   engine/render/automap_render.cpp
   engine/render/cel_render.cpp

Source/engine/load_pcx_as_cel.cpp

@@ -0,0 +1,21 @@
+#include "engine/load_pcx_as_cel.hpp"
+
+#include <SDL.h>
+
+#include "engine/assets.hpp"
+#include "utils/log.hpp"
+#include "utils/pcx_to_cel.hpp"
+
+namespace devilution {
+
+std::optional<OwnedCelSpriteWithFrameHeight> LoadPcxAssetAsCel(const char *filename, unsigned numFrames, bool generateFrameHeaders, uint8_t transparentColorIndex)
+{
+	SDL_RWops *handle = OpenAsset(filename);
+	if (handle == nullptr) {
+		LogError("Missing file: {}", filename);
+		return std::nullopt;
+	}
+	return LoadPcxAsCel(handle, numFrames, generateFrameHeaders, transparentColorIndex);
+}
+
+} // namespace devilution

Source/engine/load_pcx_as_cel.hpp

@@ -0,0 +1,12 @@
+#pragma once
+
+#include <cstdint>
+
+#include "engine/cel_sprite.hpp"
+#include "utils/stdcompat/optional.hpp"
+
+namespace devilution {
+
+std::optional<OwnedCelSpriteWithFrameHeight> LoadPcxAssetAsCel(const char *filename, unsigned numFrames, bool generateFrameHeaders = false, uint8_t transparentColorIndex = 1);
+
+} // namespace devilution

Source/engine/render/text_render.cpp

@@ -17,11 +17,11 @@
 #include "engine.h"
 #include "engine/load_cel.hpp"
 #include "engine/load_file.hpp"
+#include "engine/load_pcx_as_cel.hpp"
 #include "engine/point.hpp"
 #include "palette.h"
 #include "utils/display.h"
 #include "utils/language.h"
-#include "utils/pcx_to_cel.hpp"
 #include "utils/sdl_compat.h"
 #include "utils/stdcompat/optional.hpp"
 #include "utils/utf8.hpp"
@@ -194,17 +194,10 @@ const OwnedCelSpriteWithFrameHeight *LoadFont(GameFontTables size, text_color co
 	GetFontPath(size, row, &path[0]);
 
 	std::optional<OwnedCelSpriteWithFrameHeight> &font = Fonts[fontId];
-	SDL_RWops *handle = OpenAsset(path);
-	if (handle == nullptr) {
-		LogError("Missing font: {}", path);
-		return nullptr;
-	}
-
 	constexpr unsigned NumFrames = 256;
-	font = LoadPcxAsCel(handle, NumFrames, /*generateFrameHeaders=*/false);
-	if (font->sprite.Data() == nullptr) {
+	font = LoadPcxAssetAsCel(path, NumFrames);
+	if (!font) {
 		LogError("Error loading font: {}", path);
-		font = std::nullopt;
 		return nullptr;
 	}
 

Source/utils/pcx_to_cel.cpp

@@ -18,8 +18,6 @@ namespace devilution {
 
 namespace {
 
-constexpr uint8_t PcxTransparentColorIndex = 1;
-
 void WriteLE32(uint8_t *out, uint32_t val)
 {
 	const uint32_t littleEndian = SDL_SwapLE32(val);
@@ -32,26 +30,40 @@ void WriteLE16(uint8_t *out, uint16_t val)
 	memcpy(out, &littleEndian, 2);
 }
 
-void AppendCelTransparentRun(uint8_t width, std::vector<uint8_t> &out)
+void AppendCelTransparentRun(unsigned width, std::vector<uint8_t> &out)
 {
+	while (width >= 128) {
+		out.push_back(0x80);
+		width -= 128;
+	}
+	if (width == 0)
+		return;
 	out.push_back(0xFF - (width - 1));
 }
 
 void AppendCelSolidRun(const uint8_t *src, unsigned width, std::vector<uint8_t> &out)
 {
-	assert(width < 126);
+	while (width >= 127) {
+		out.push_back(127);
+		for (size_t i = 0; i < 127; ++i)
+			out.push_back(src[i]);
+		width -= 127;
+		src += 127;
+	}
+	if (width == 0)
+		return;
 	out.push_back(width);
 	for (size_t i = 0; i < width; ++i)
 		out.push_back(src[i]);
 }
 
-void AppendCelLine(const uint8_t *src, unsigned width, std::vector<uint8_t> &out)
+void AppendCelLine(const uint8_t *src, unsigned width, uint8_t transparentColorIndex, std::vector<uint8_t> &out)
 {
 	unsigned runBegin = 0;
 	bool transparentRun = false;
 	for (unsigned i = 0; i < width; ++i) {
 		const uint8_t pixel = src[i];
-		if (pixel == PcxTransparentColorIndex) {
+		if (pixel == transparentColorIndex) {
 			if (transparentRun)
 				continue;
 			if (runBegin != i)
@@ -73,7 +85,7 @@ void AppendCelLine(const uint8_t *src, unsigned width, std::vector<uint8_t> &out
 
 } // namespace
 
-std::optional<OwnedCelSpriteWithFrameHeight> LoadPcxAsCel(SDL_RWops *handle, unsigned numFrames, bool generateFrameHeaders)
+std::optional<OwnedCelSpriteWithFrameHeight> LoadPcxAsCel(SDL_RWops *handle, unsigned numFrames, bool generateFrameHeaders, uint8_t transparentColorIndex)
 {
 	int width;
 	int height;
@@ -83,10 +95,9 @@ std::optional<OwnedCelSpriteWithFrameHeight> LoadPcxAsCel(SDL_RWops *handle, uns
 		return std::nullopt;
 	}
 	assert(bpp == 8);
-	assert(width <= 128);
 
-	uint32_t pixelDataSize = SDL_RWsize(handle);
-	if (pixelDataSize == static_cast<uint32_t>(-1)) {
+	ptrdiff_t pixelDataSize = SDL_RWsize(handle);
+	if (pixelDataSize < 0) {
 		SDL_RWclose(handle);
 		return std::nullopt;
 	}
@@ -141,20 +152,20 @@ std::optional<OwnedCelSpriteWithFrameHeight> LoadPcxAsCel(SDL_RWops *handle, uns
 
 		size_t line = frameHeight;
 		while (line-- != 0) {
-			AppendCelLine(&frameBuffer[line * width], width, celData);
+			AppendCelLine(&frameBuffer[line * width], width, transparentColorIndex, celData);
 			if (generateFrameHeaders) {
 				switch (line) {
 				case 32:
-					WriteLE16(&celData[frameHeaderPos + 2], celData.size() - frameHeaderPos);
+					WriteLE16(&celData[frameHeaderPos + 2], static_cast<uint16_t>(celData.size() - frameHeaderPos));
 					break;
 				case 64:
-					WriteLE16(&celData[frameHeaderPos + 4], celData.size() - frameHeaderPos);
+					WriteLE16(&celData[frameHeaderPos + 4], static_cast<uint16_t>(celData.size() - frameHeaderPos));
 					break;
 				case 96:
-					WriteLE16(&celData[frameHeaderPos + 6], celData.size() - frameHeaderPos);
+					WriteLE16(&celData[frameHeaderPos + 6], static_cast<uint16_t>(celData.size() - frameHeaderPos));
 					break;
 				case 128:
-					WriteLE16(&celData[frameHeaderPos + 8], celData.size() - frameHeaderPos);
+					WriteLE16(&celData[frameHeaderPos + 8], static_cast<uint16_t>(celData.size() - frameHeaderPos));
 					break;
 				}
 			}
@@ -168,7 +179,7 @@ std::optional<OwnedCelSpriteWithFrameHeight> LoadPcxAsCel(SDL_RWops *handle, uns
 	memcpy(&out[0], celData.data(), celData.size());
 	return OwnedCelSpriteWithFrameHeight {
 		OwnedCelSprite { std::move(out), static_cast<uint16_t>(width) },
-		static_cast<unsigned>(frameHeight)
+		frameHeight
 	};
 }
 

Source/utils/pcx_to_cel.hpp

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <cstdint>
+
 #include <SDL.h>
 
 #include "engine/cel_sprite.hpp"
@@ -14,7 +16,9 @@ namespace devilution {
  * @param handle A non-null SDL_RWops handle. Closed by this function.
  * @param numFrames The number of vertically stacked frames in the PCX file.
  * @param generateFrameHeaders Whether to generate frame headers in the CEL sprite.
+ * @param transparentColorIndex The PCX palette index of the transparent color.
  */
-std::optional<OwnedCelSpriteWithFrameHeight> LoadPcxAsCel(SDL_RWops *handle, unsigned numFrames, bool generateFrameHeaders);
+std::optional<OwnedCelSpriteWithFrameHeight> LoadPcxAsCel(SDL_RWops *handle, unsigned numFrames, bool generateFrameHeaders,
+    uint8_t transparentColorIndex = 1);
 
 } // namespace devilution