Informs retroarch that PNG extension is also supported (#2832)

* Informs retroarch that PNG extension is also supported

* Loading PNG cart from cart.c (fix PNG load in libretro)

Moved loadPngCart from studio.c to cart.c
The standalone binary loads carts from this stack:
studio.c: studio_create()
console.c: initConsole()
console.c: cmdLoadCart()

cmdLoadCart() had a working PNG cart load,
but libretro uses `tic.c: tic80_load()` directlty, but that had a
incompete PNG load.

So I tried to combine and bring the aproach from cmdLoadCart() to
tic80_load() by letting them both use the same PNG loading function.

* libpng CMakelist - order may matter

* target_link_libraries(tic80core PRIVATE png)

Author: imsys

CMakeLists.txt

@@ -152,6 +152,7 @@ include(cmake/gif.cmake)
 include(cmake/blipbuf.cmake)
 include(cmake/zlib.cmake)
 include(cmake/zip.cmake)
+include(cmake/png.cmake)
 include(cmake/tools.cmake)
 
 include(cmake/lua.cmake)
@@ -170,7 +171,6 @@ include(cmake/core.cmake)
 include(cmake/wave.cmake)
 include(cmake/argparse.cmake)
 include(cmake/naett.cmake)
-include(cmake/png.cmake)
 include(cmake/studio.cmake)
 
 include(cmake/sdl.cmake)

cmake/core.cmake

@@ -29,6 +29,7 @@ set(TIC80CORE_SRC
     ${TIC80CORE_DIR}/ext/fft.c
     ${TIC80CORE_DIR}/ext/kiss_fft.c
     ${TIC80CORE_DIR}/ext/kiss_fftr.c
+    ${TIC80CORE_DIR}/ext/png.c
 )
 
 if(BUILD_DEPRECATED)
@@ -55,6 +56,7 @@ target_include_directories(tic80core
         ${CMAKE_SOURCE_DIR}/include
         ${CMAKE_SOURCE_DIR}/src)
 
+target_link_libraries(tic80core PRIVATE png)
 target_link_libraries(tic80core PRIVATE blipbuf)
 
 if(BUILD_WITH_ZLIB)

cmake/studio.cmake

@@ -13,6 +13,7 @@ set(TIC80STUDIO_SRC
     ${TIC80LIB_DIR}/studio/fs.c
     ${TIC80LIB_DIR}/ext/md5.c
     ${TIC80LIB_DIR}/ext/json.c
+    ${TIC80LIB_DIR}/ext/png.c
 )
 
 if(BUILD_EDITORS)
@@ -28,7 +29,6 @@ if(BUILD_EDITORS)
         ${TIC80LIB_DIR}/studio/net.c
         ${TIC80LIB_DIR}/ext/history.c
         ${TIC80LIB_DIR}/ext/gif.c
-        ${TIC80LIB_DIR}/ext/png.c
     )
 endif()
 

src/cart.c

@@ -32,6 +32,7 @@
 #include <stdlib.h>
 #include "tic_assert.h"
 #include "tools.h"
+#include "ext/png.h"
 
 typedef enum
 {
@@ -81,6 +82,42 @@ static s32 chunkSize(const Chunk* chunk)
     return chunk->size == 0 && (chunk->type == CHUNK_CODE || chunk->type == CHUNK_BINARY) ? TIC_BANK_SIZE : retro_le_to_cpu16(chunk->size);
 }
 
+static png_buffer getRawCartFromPng(png_buffer buffer)
+{
+    png_buffer zip = png_decode(buffer);
+
+    if (zip.size)
+    {
+        png_buffer buf = png_create(sizeof(tic_cartridge));
+
+        buf.size = tic_tool_unzip(buf.data, buf.size, zip.data, zip.size);
+        free(zip.data);
+
+        if(buf.size)
+            return buf;
+
+        free(buf.data);
+    }
+
+    return (png_buffer){.data = NULL, .size = 0};
+}
+
+tic_cartridge* loadPngCart(png_buffer buffer)
+{
+    png_buffer buf = getRawCartFromPng(buffer);
+
+    if(buf.data)
+    {
+        tic_cartridge* cart = malloc(sizeof(tic_cartridge));
+        tic_cart_load(cart, buf.data, buf.size);
+        free(buf.data);
+
+        return cart;
+    }
+
+    return NULL;
+}
+
 void tic_cart_load(tic_cartridge* cart, const u8* buffer, s32 size)
 {
     memset(cart, 0, sizeof(tic_cartridge));
@@ -90,27 +127,16 @@ void tic_cart_load(tic_cartridge* cart, const u8* buffer, s32 size)
     // check if this cartridge is in PNG format
     if (!memcmp(buffer, "\x89PNG", 4))
     {
-        s32 siz;
-        const u8* ptr = buffer + 8;
-        // iterate on chunks until we find a cartridge
-        while (ptr < end)
+        png_buffer buf = getRawCartFromPng((png_buffer){.data = (u8*)buffer, .size = size});
+
+        if(buf.data)
         {
-            siz = ((ptr[0] << 24) | (ptr[1] << 16) | (ptr[2] << 8) | ptr[3]);
-            if (!memcmp(ptr + 4, "caRt", 4) && siz > 0)
-            {
-                chunk_cart = malloc(sizeof(tic_cartridge));
-                if (chunk_cart)
-                {
-                    size = tic_tool_unzip(chunk_cart, sizeof(tic_cartridge), ptr + 8, siz);
-                    buffer = chunk_cart;
-                    end = buffer + size;
-                }
-                break;
-            }
-            ptr += siz + 12;
+            chunk_cart = buf.data;
+            buffer = buf.data;
+            size = buf.size;
+            end = buffer + size;
         }
-        // error, no TIC-80 cartridge chunk in PNG???
-        if (!chunk_cart)
+        else
             return;
     }
 

src/studio/studio.c

@@ -1531,30 +1531,6 @@ bool project_ext(const char* name)
     return false;
 }
 
-tic_cartridge* loadPngCart(png_buffer buffer)
-{
-    png_buffer zip = png_decode(buffer);
-
-    if (zip.size)
-    {
-        png_buffer buf = png_create(sizeof(tic_cartridge));
-
-        buf.size = tic_tool_unzip(buf.data, buf.size, zip.data, zip.size);
-        free(zip.data);
-
-        if(buf.size)
-        {
-            tic_cartridge* cart = malloc(sizeof(tic_cartridge));
-            tic_cart_load(cart, buf.data, buf.size);
-            free(buf.data);
-
-            return cart;
-        }
-    }
-
-    return NULL;
-}
-
 void studioRomSaved(Studio* studio)
 {
     updateTitle(studio);

src/system/libretro/tic80_libretro.c

@@ -336,7 +336,7 @@ RETRO_API void retro_get_system_info(struct retro_system_info *info)
 	memset(info, 0, sizeof(*info));
 	info->library_name     = TIC_NAME;
 	info->library_version  = TIC_VERSION;
-	info->valid_extensions = "tic";
+	info->valid_extensions = "tic|png";
 	info->need_fullpath    = false;
 	info->block_extract    = false;
 }