(svn r10143) -Add: store the filename of the grfs opened and allow easy access to the name

-Codechange: store the SpriteID in the spritecache too
-Add: add a PNG loader for graphical files
-Documentation: added a document to explain the PNG format

8 files changed, 244 insertions, 6 deletions

diff --git a/src/fileio.cpp b/src/fileio.cpp
index 171f6bfcd..f8173ab86 100644
--- a/src/fileio.cpp
+++ b/src/fileio.cpp
@@ -28,11 +28,12 @@ struct Fio {
 	byte *buffer, *buffer_end;          ///< position pointer in local buffer and last valid byte of buffer
 	uint32 pos;                         ///< current (system) position in file
 	FILE *cur_fh;                       ///< current file handle
+	const char *filename;               ///< current filename
 	FILE *handles[MAX_HANDLES];         ///< array of file handles we can have open
 	byte buffer_start[FIO_BUFFER_SIZE]; ///< local buffer when read from file
+	const char *filenames[MAX_HANDLES]; ///< array of filenames we (should) have open
 #if defined(LIMITED_FDS)
 	uint open_handles;                  ///< current amount of open handles
-	const char *filename[MAX_HANDLES];  ///< array of filenames we (should) have open
 	uint usage_count[MAX_HANDLES];      ///< count how many times this file has been opened
 #endif /* LIMITED_FDS */
 };
@@ -45,6 +46,11 @@ uint32 FioGetPos()
 	return _fio.pos + (_fio.buffer - _fio.buffer_start) - FIO_BUFFER_SIZE;
 }
 
+const char *FioGetFilename()
+{
+	return _fio.filename;
+}
+
 void FioSeekTo(uint32 pos, int mode)
 {
 	if (mode == SEEK_CUR) pos += FioGetPos();
@@ -76,6 +82,7 @@ void FioSeekToFile(uint32 pos)
 	f = _fio.handles[pos >> 24];
 	assert(f != NULL);
 	_fio.cur_fh = f;
+	_fio.filename = _fio.filenames[pos >> 24];
 	FioSeekTo(GB(pos, 0, 24), SEEK_SET);
 }
 
@@ -174,8 +181,8 @@ void FioOpenFile(int slot, const char *filename)
 
 	FioCloseFile(slot); // if file was opened before, close it
 	_fio.handles[slot] = f;
+	_fio.filenames[slot] = filename;
 #if defined(LIMITED_FDS)
-	_fio.filename[slot] = filename;
 	_fio.usage_count[slot] = 0;
 	_fio.open_handles++;
 #endif /* LIMITED_FDS */
diff --git a/src/fileio.h b/src/fileio.h
index 7835a5c8a..97a62249f 100644
--- a/src/fileio.h
+++ b/src/fileio.h
@@ -8,6 +8,7 @@
 void FioSeekTo(uint32 pos, int mode);
 void FioSeekToFile(uint32 pos);
 uint32 FioGetPos();
+const char *FioGetFilename();
 byte FioReadByte();
 uint16 FioReadWord();
 uint32 FioReadDword();
diff --git a/src/spritecache.cpp b/src/spritecache.cpp
index 4a43faf2a..1a2721946 100644
--- a/src/spritecache.cpp
+++ b/src/spritecache.cpp
@@ -4,6 +4,8 @@
 
 #include "stdafx.h"
 #include "openttd.h"
+#include "variables.h"
+#include "string.h"
 #include "debug.h"
 #include "functions.h"
 #include "macros.h"
@@ -12,6 +14,7 @@
 #include "fileio.h"
 #include "helpers.hpp"
 #include "spriteloader/grf.hpp"
+#include "spriteloader/png.hpp"
 #include "blitter/blitter.hpp"
 
 /* Default of 4MB spritecache */
@@ -22,6 +25,8 @@ struct SpriteCache {
 	void *ptr;
 	uint32 file_pos;
 	int16 lru;
+	uint32 id;
+	const char *grf_name;
 };
 
 
@@ -132,6 +137,20 @@ static void* ReadSprite(SpriteCache *sc, SpriteID id, bool real_sprite)
 		file_pos = GetSpriteCache(SPR_IMG_QUERY)->file_pos;
 	}
 
+	if (BlitterFactoryBase::GetCurrentBlitter()->GetScreenDepth() == 32) {
+		/* Try loading 32bpp graphics in case we are 32bpp output */
+		SpriteLoaderPNG sprite_loader;
+		SpriteLoader::Sprite sprite;
+
+		if (sprite_loader.LoadSprite(&sprite, sc->grf_name, sc->id)) {
+			sc->ptr = BlitterFactoryBase::GetCurrentBlitter()->Encode(&sprite, &AllocSprite);
+			free(sprite.data);
+
+			return sc->ptr;
+		}
+		/* If the PNG couldn't be loaded, fall back to 8bpp grfs */
+	}
+
 	FioSeekToFile(file_pos);
 
 	/* Read the size and type */
@@ -203,7 +222,7 @@ static void* ReadSprite(SpriteCache *sc, SpriteID id, bool real_sprite)
 	SpriteLoaderGrf sprite_loader;
 	SpriteLoader::Sprite sprite;
 
-	if (!sprite_loader.LoadSprite(&sprite, file_pos)) return NULL;
+	if (!sprite_loader.LoadSprite(&sprite, sc->grf_name, file_pos)) return NULL;
 	if (id == 142) sprite.height = 10; // Compensate for a TTD bug
 	sc->ptr = BlitterFactoryBase::GetCurrentBlitter()->Encode(&sprite, &AllocSprite);
 	free(sprite.data);
@@ -227,6 +246,17 @@ bool LoadNextSprite(int load_index, byte file_index)
 	sc->file_pos = file_pos;
 	sc->ptr = NULL;
 	sc->lru = 0;
+	sc->id = load_index;
+
+	char *grf_name = strrchr(FioGetFilename(), PATHSEPCHAR);
+	if (grf_name == NULL) grf_name = (char *)FioGetFilename();
+	/* Copy the string, make it lowercase, strip .grf */
+	grf_name = strdup(grf_name);
+	char *t = strrchr(grf_name, '.');
+	if (t != NULL) *t = '\0';
+	strtolower(grf_name);
+	free((char *)sc->grf_name);
+	sc->grf_name = grf_name;
 
 	return true;
 }
@@ -239,6 +269,8 @@ void DupSprite(SpriteID old_spr, SpriteID new_spr)
 
 	scnew->file_pos = scold->file_pos;
 	scnew->ptr = NULL;
+	scnew->id = scold->id;
+	scnew->grf_name = strdup(scold->grf_name);
 }
 
 
diff --git a/src/spriteloader/grf.cpp b/src/spriteloader/grf.cpp
index 7b72f1ac1..79095e4db 100644
--- a/src/spriteloader/grf.cpp
+++ b/src/spriteloader/grf.cpp
@@ -8,7 +8,7 @@
 #include "../debug.h"
 #include "grf.hpp"
 
-bool SpriteLoaderGrf::LoadSprite(SpriteLoader::Sprite *sprite, uint32 file_pos)
+bool SpriteLoaderGrf::LoadSprite(SpriteLoader::Sprite *sprite, const char *filename, uint32 file_pos)
 {
 	/* Open the right file and go to the correct position */
 	FioSeekToFile(file_pos);
diff --git a/src/spriteloader/grf.hpp b/src/spriteloader/grf.hpp
index 27083f993..e6e67be15 100644
--- a/src/spriteloader/grf.hpp
+++ b/src/spriteloader/grf.hpp
@@ -12,7 +12,7 @@ public:
 	/**
 	 * Load a sprite from the disk and return a sprite struct which is the same for all loaders.
 	 */
-	bool LoadSprite(SpriteLoader::Sprite *sprite, uint32 file_pos);
+	bool LoadSprite(SpriteLoader::Sprite *sprite, const char *filename, uint32 file_pos);
 };
 
 #endif /* SPRITELOADER_GRF_HPP */
diff --git a/src/spriteloader/png.cpp b/src/spriteloader/png.cpp
new file mode 100644
index 000000000..bd735ce43
--- /dev/null
+++ b/src/spriteloader/png.cpp
@@ -0,0 +1,180 @@
+/* $Id$ */
+
+/** @file grf.cpp */
+
+#include "../stdafx.h"
+#include "../gfx.h"
+#include "../fileio.h"
+#include "../variables.h"
+#include "../debug.h"
+#include "png.hpp"
+#include <png.h>
+
+#define PNG_SLOT 62
+
+static void PNGAPI png_my_read(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+	FioReadBlock(data, length);
+}
+
+static void PNGAPI png_my_error(png_structp png_ptr, png_const_charp message)
+{
+	DEBUG(sprite, 0, "ERROR (libpng): %s - %s", message, (char *)png_get_error_ptr(png_ptr));
+	longjmp(png_ptr->jmpbuf, 1);
+}
+
+static void PNGAPI png_my_warning(png_structp png_ptr, png_const_charp message)
+{
+	DEBUG(sprite, 0, "WARNING (libpng): %s - %s", message, (char *)png_get_error_ptr(png_ptr));
+}
+
+static bool OpenPNGFile(const char *filename, uint32 id, bool mask)
+{
+	char png_file[MAX_PATH];
+
+	snprintf(png_file, sizeof(png_file), "sprites" PATHSEP "%s" PATHSEP "%d%s.png", filename, id, mask ? "m" : "");
+	if (FioCheckFileExists(png_file)) {
+		FioOpenFile(PNG_SLOT, png_file);
+		return true;
+	}
+
+	/* TODO -- Add TAR support */
+	return false;
+}
+
+static bool LoadPNG(SpriteLoader::Sprite *sprite, const char *filename, uint32 id, bool mask)
+{
+	png_byte header[8];
+	png_structp png_ptr;
+	png_infop info_ptr, end_info;
+	uint bit_depth, color_type;
+	uint i, pixelsize;
+	png_bytep row_pointer;
+	SpriteLoader::CommonPixel *dst;
+
+	if (!OpenPNGFile(filename, id, mask)) return mask; // If mask is true, and file not found, continue true anyway, as it isn't a show-stopper
+
+	/* Check the header */
+	FioReadBlock(header, 8);
+	if (png_sig_cmp(header, 0, 8) != 0) return false;
+
+	/* Create the reader */
+	png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL, png_my_error, png_my_warning);
+	if (png_ptr == NULL) return false;
+
+	/* Create initial stuff */
+	info_ptr = png_create_info_struct(png_ptr);
+	if (info_ptr == NULL) {
+		png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
+		return false;
+	}
+	end_info = png_create_info_struct(png_ptr);
+	if (end_info == NULL) {
+		png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
+		return false;
+	}
+
+	/* Make sure that upon error, we can clean up graceful */
+	if (setjmp(png_jmpbuf(png_ptr))) {
+		png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+		return false;
+	}
+
+	/* Read the file */
+	png_set_read_fn(png_ptr, NULL, png_my_read);
+	png_set_sig_bytes(png_ptr, 8);
+
+	png_read_info(png_ptr, info_ptr);
+
+	if (!mask) {
+		/* Read the text chunks */
+		png_textp text_ptr;
+		int num_text = 0;
+		png_get_text(png_ptr, info_ptr, &text_ptr, &num_text);
+		if (num_text == 0) DEBUG(misc, 0, "Warning: PNG Sprite '%s/%d.png' doesn't have x_offs and y_offs; expect graphical problems", filename, id);
+		for (int i = 0; i < num_text; i++) {
+			/* x_offs and y_offs are in the text-chunk of PNG */
+			if (strcmp("x_offs", text_ptr[i].key) == 0) sprite->x_offs = strtol(text_ptr[i].text, NULL, 0);
+			if (strcmp("y_offs", text_ptr[i].key) == 0) sprite->y_offs = strtol(text_ptr[i].text, NULL, 0);
+		}
+
+		sprite->height = info_ptr->height;
+		sprite->width  = info_ptr->width;
+		sprite->data = CallocT<SpriteLoader::CommonPixel>(sprite->width * sprite->height);
+	}
+
+	bit_depth  = png_get_bit_depth(png_ptr, info_ptr);
+	color_type = png_get_color_type(png_ptr, info_ptr);
+
+	if (mask && (bit_depth != 8 || color_type != PNG_COLOR_TYPE_PALETTE)) {
+		DEBUG(misc, 0, "Ignoring mask for SpriteID %d as it isn't a 8 bit palette image", id);
+		return true;
+	}
+
+	if (!mask) {
+		if (bit_depth == 16) png_set_strip_16(png_ptr);
+
+		if (color_type == PNG_COLOR_TYPE_PALETTE) png_set_palette_to_rgb(png_ptr);
+	/* TODO 32bpp: Convert grayscale to rgb */
+
+#ifdef TTD_LITTLE_ENDIAN
+		png_set_bgr(png_ptr);
+#else
+		if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) png_set_swap_alpha(png_ptr);
+#endif
+
+		if (color_type == PNG_COLOR_TYPE_RGB) {
+#ifdef TTD_LITTLE_ENDIAN
+			png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
+#else
+			png_set_filler(png_ptr, 0xff, PNG_FILLER_BEFORE);
+#endif
+		}
+
+		pixelsize = sizeof(uint32);
+	} else {
+		pixelsize = sizeof(uint8);
+	}
+
+	row_pointer = (png_byte *)malloc(info_ptr->width * pixelsize);
+	if (row_pointer == NULL) {
+		png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+		return false;
+	}
+
+	for (i = 0; i < info_ptr->height; i++) {
+		png_read_row(png_ptr, row_pointer, NULL);
+
+		dst = sprite->data + i * info_ptr->width;
+
+		for (uint x = 0; x < info_ptr->width; x++) {
+			if (mask) {
+				if (row_pointer[x * sizeof(uint8)] != 0) {
+					dst[x].b = 0;
+					dst[x].g = 0;
+					dst[x].r = 0;
+					/* Alpha channel is used from the original image (to allow transparency in remap colors) */
+					dst[x].m = row_pointer[x * sizeof(uint8)];
+				}
+			} else {
+				dst[x].b = row_pointer[x * sizeof(uint32) + 0];
+				dst[x].g = row_pointer[x * sizeof(uint32) + 1];
+				dst[x].r = row_pointer[x * sizeof(uint32) + 2];
+				dst[x].a = row_pointer[x * sizeof(uint32) + 3];
+				dst[x].m = 0;
+			}
+		}
+	}
+
+	free(row_pointer);
+	png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+
+	return true;
+}
+
+bool SpriteLoaderPNG::LoadSprite(SpriteLoader::Sprite *sprite, const char *filename, uint32 file_pos)
+{
+	if (!LoadPNG(sprite, filename, file_pos, false)) return false;
+	if (!LoadPNG(sprite, filename, file_pos, true)) return false;
+	return true;
+}
diff --git a/src/spriteloader/png.hpp b/src/spriteloader/png.hpp
new file mode 100644
index 000000000..737501268
--- /dev/null
+++ b/src/spriteloader/png.hpp
@@ -0,0 +1,18 @@
+/* $Id$ */
+
+/** @file png.hpp */
+
+#ifndef SPRITELOADER_PNG_HPP
+#define SPRITELOADER_PNG_HPP
+
+#include "spriteloader.hpp"
+
+class SpriteLoaderPNG : public SpriteLoader {
+public:
+	/**
+	 * Load a sprite from the disk and return a sprite struct which is the same for all loaders.
+	 */
+	bool LoadSprite(SpriteLoader::Sprite *sprite, const char *filename, uint32 file_pos);
+};
+
+#endif /* SPRITELOADER_PNG_HPP */
diff --git a/src/spriteloader/spriteloader.hpp b/src/spriteloader/spriteloader.hpp
index 658277236..fe0e6ab8e 100644
--- a/src/spriteloader/spriteloader.hpp
+++ b/src/spriteloader/spriteloader.hpp
@@ -26,7 +26,7 @@ public:
 	/**
 	 * Load a sprite from the disk and return a sprite struct which is the same for all loaders.
 	 */
-	virtual bool LoadSprite(SpriteLoader::Sprite *sprite, uint32 file_pos) = 0;
+	virtual bool LoadSprite(SpriteLoader::Sprite *sprite, const char *filename, uint32 file_pos) = 0;
 
 	virtual ~SpriteLoader() { }
 };