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authorhecks <42101236+hecktest@users.noreply.github.com>2021-07-29 05:10:10 +0200
committerGitHub <noreply@github.com>2021-07-29 05:10:10 +0200
commit80d12dbedb67191a5eb3e4f3c36b04baed1f8afb (patch)
treeca8346be45852e0c08f444f8a8eb6c0cdfd37e39 /src
parent2866918f3293c486609ff46ad0bfa5ce833aaaf2 (diff)
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Add a simple PNG image encoder with Lua API (#11485)
* Add a simple PNG image encoder with Lua API Add ColorSpec to RGBA converter Make a safety wrapper for the encoder Create devtest examples Co-authored-by: hecktest <> Co-authored-by: sfan5 <sfan5@live.de>
Diffstat (limited to 'src')
-rw-r--r--src/script/lua_api/l_util.cpp43
-rw-r--r--src/script/lua_api/l_util.h6
-rw-r--r--src/util/CMakeLists.txt1
-rwxr-xr-xsrc/util/png.cpp68
-rwxr-xr-xsrc/util/png.h27
5 files changed, 145 insertions, 0 deletions
diff --git a/src/script/lua_api/l_util.cpp b/src/script/lua_api/l_util.cpp
index 8de2d67c8..87436fce0 100644
--- a/src/script/lua_api/l_util.cpp
+++ b/src/script/lua_api/l_util.cpp
@@ -40,6 +40,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
#include "version.h"
#include "util/hex.h"
#include "util/sha1.h"
+#include "util/png.h"
#include <algorithm>
#include <cstdio>
@@ -497,6 +498,43 @@ int ModApiUtil::l_colorspec_to_colorstring(lua_State *L)
return 0;
}
+// colorspec_to_bytes(colorspec)
+int ModApiUtil::l_colorspec_to_bytes(lua_State *L)
+{
+ NO_MAP_LOCK_REQUIRED;
+
+ video::SColor color(0);
+ if (read_color(L, 1, &color)) {
+ u8 colorbytes[4] = {
+ (u8) color.getRed(),
+ (u8) color.getGreen(),
+ (u8) color.getBlue(),
+ (u8) color.getAlpha(),
+ };
+ lua_pushlstring(L, (const char*) colorbytes, 4);
+ return 1;
+ }
+
+ return 0;
+}
+
+// encode_png(w, h, data, level)
+int ModApiUtil::l_encode_png(lua_State *L)
+{
+ NO_MAP_LOCK_REQUIRED;
+
+ // The args are already pre-validated on the lua side.
+ u32 width = readParam<int>(L, 1);
+ u32 height = readParam<int>(L, 2);
+ const char *data = luaL_checklstring(L, 3, NULL);
+ s32 compression = readParam<int>(L, 4);
+
+ std::string out = encodePNG((const u8*)data, width, height, compression);
+
+ lua_pushlstring(L, out.data(), out.size());
+ return 1;
+}
+
void ModApiUtil::Initialize(lua_State *L, int top)
{
API_FCT(log);
@@ -532,6 +570,9 @@ void ModApiUtil::Initialize(lua_State *L, int top)
API_FCT(get_version);
API_FCT(sha1);
API_FCT(colorspec_to_colorstring);
+ API_FCT(colorspec_to_bytes);
+
+ API_FCT(encode_png);
LuaSettings::create(L, g_settings, g_settings_path);
lua_setfield(L, top, "settings");
@@ -557,6 +598,7 @@ void ModApiUtil::InitializeClient(lua_State *L, int top)
API_FCT(get_version);
API_FCT(sha1);
API_FCT(colorspec_to_colorstring);
+ API_FCT(colorspec_to_bytes);
}
void ModApiUtil::InitializeAsync(lua_State *L, int top)
@@ -585,6 +627,7 @@ void ModApiUtil::InitializeAsync(lua_State *L, int top)
API_FCT(get_version);
API_FCT(sha1);
API_FCT(colorspec_to_colorstring);
+ API_FCT(colorspec_to_bytes);
LuaSettings::create(L, g_settings, g_settings_path);
lua_setfield(L, top, "settings");
diff --git a/src/script/lua_api/l_util.h b/src/script/lua_api/l_util.h
index 6943a6afb..54d2be619 100644
--- a/src/script/lua_api/l_util.h
+++ b/src/script/lua_api/l_util.h
@@ -104,6 +104,12 @@ private:
// colorspec_to_colorstring(colorspec)
static int l_colorspec_to_colorstring(lua_State *L);
+ // colorspec_to_bytes(colorspec)
+ static int l_colorspec_to_bytes(lua_State *L);
+
+ // encode_png(w, h, data, level)
+ static int l_encode_png(lua_State *L);
+
public:
static void Initialize(lua_State *L, int top);
static void InitializeAsync(lua_State *L, int top);
diff --git a/src/util/CMakeLists.txt b/src/util/CMakeLists.txt
index cd2e468d1..6bc97915f 100644
--- a/src/util/CMakeLists.txt
+++ b/src/util/CMakeLists.txt
@@ -15,4 +15,5 @@ set(UTIL_SRCS
${CMAKE_CURRENT_SOURCE_DIR}/string.cpp
${CMAKE_CURRENT_SOURCE_DIR}/srp.cpp
${CMAKE_CURRENT_SOURCE_DIR}/timetaker.cpp
+ ${CMAKE_CURRENT_SOURCE_DIR}/png.cpp
PARENT_SCOPE)
diff --git a/src/util/png.cpp b/src/util/png.cpp
new file mode 100755
index 000000000..7ac2e94a1
--- /dev/null
+++ b/src/util/png.cpp
@@ -0,0 +1,68 @@
+/*
+Minetest
+Copyright (C) 2021 hecks
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "png.h"
+#include <string>
+#include <sstream>
+#include <zlib.h>
+#include <cassert>
+#include "util/serialize.h"
+#include "serialization.h"
+#include "irrlichttypes.h"
+
+static void writeChunk(std::ostringstream &target, const std::string &chunk_str)
+{
+ assert(chunk_str.size() >= 4);
+ assert(chunk_str.size() - 4 < U32_MAX);
+ writeU32(target, chunk_str.size() - 4); // Write length minus the identifier
+ target << chunk_str;
+ writeU32(target, crc32(0,(const u8*)chunk_str.data(), chunk_str.size()));
+}
+
+std::string encodePNG(const u8 *data, u32 width, u32 height, s32 compression)
+{
+ auto file = std::ostringstream(std::ios::binary);
+ file << "\x89PNG\r\n\x1a\n";
+
+ {
+ auto IHDR = std::ostringstream(std::ios::binary);
+ IHDR << "IHDR";
+ writeU32(IHDR, width);
+ writeU32(IHDR, height);
+ // 8 bpp, color type 6 (RGBA)
+ IHDR.write("\x08\x06\x00\x00\x00", 5);
+ writeChunk(file, IHDR.str());
+ }
+
+ {
+ auto IDAT = std::ostringstream(std::ios::binary);
+ IDAT << "IDAT";
+ auto scanlines = std::ostringstream(std::ios::binary);
+ for(u32 i = 0; i < height; i++) {
+ scanlines.write("\x00", 1); // Null predictor
+ scanlines.write((const char*) data + width * 4 * i, width * 4);
+ }
+ compressZlib(scanlines.str(), IDAT, compression);
+ writeChunk(file, IDAT.str());
+ }
+
+ file.write("\x00\x00\x00\x00IEND\xae\x42\x60\x82", 12);
+
+ return file.str();
+}
diff --git a/src/util/png.h b/src/util/png.h
new file mode 100755
index 000000000..92387aef0
--- /dev/null
+++ b/src/util/png.h
@@ -0,0 +1,27 @@
+/*
+Minetest
+Copyright (C) 2021 hecks
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include <string>
+#include "irrlichttypes.h"
+
+/* Simple PNG encoder. Encodes an RGBA image with no predictors.
+ Returns a binary string. */
+std::string encodePNG(const u8 *data, u32 width, u32 height, s32 compression);