Now, having OpenGL ES projects for 2 different platforms, we can see what is common and what is different.<\/p>\n\n\n\n
Common is generic structure: Creating GL context, initializing data, main loop with frames rendering, exit. GL calls (Thank God!) look similar too. The difference is in program and GL initialization, in GL-related includes (gl\/egl on Android and glfw\/glad in Windows). Events and input handling are different as well.<\/p>\n\n\n\n
Well, let\u2019s encapsulate platform-specific stuff in 2 separate sets (one for PC and another one for Android).<\/p>\n\n\n\n
We will start here from printf-alike function, which is essential for development, and obviously will require 2 different implementations for Windows and for Android. We’ll start in<\/p>\n\n\n\n
2. Add a placeholder: right-click on \u201cp_windows<\/em> \u201d project -> Add -> New Filter<\/strong><\/em><\/p>\n\n\n\n Name – xPlatform<\/strong><\/p>\n\n\n\n 3. Physically we will keep Windows-specific files in C:\\CPP\\p_windows<\/em> folder. Need to inform Project about this new location:<\/p>\n\n\n\n Right-click on \u201cp_windows<\/strong>\u201d project -> Properties<\/em>, All configurations<\/strong>, Win32<\/strong>, Configuration properties -> C++ -> General<\/em> -> Additional Include Directories -> Edit<\/em>, add New Line, browse to<\/p>\n\n\n\n C:\\CPP\\p_windows<\/em><\/p>\n\n\n\n Select Folder, Ok, Apply, Ok<\/strong><\/p>\n\n\n\n 4. Under xPlatform<\/em> add a header file: Right-click on xPlatform<\/em>, Add -> New Item<\/em>,<\/p>\n\n\n\n Then \u2013 Add<\/strong>.<\/p>\n\n\n\n As was announced above, we will write a function that can print something on the screen (in our case \u2013 in Console window), something like printf.<\/p>\n\n\n\n We can\u2019t use printf directly because:<\/p>\n\n\n\n I’ll call it mylog()<\/em>. I want it to accept parameters the same way as printf (format string first and then \u2013 whatever).<\/p>\n\n\n\n Also, it should do nothing in Release configuration. So, the code is:<\/p>\n\n\n <\/p>\n\n\n\n Now we are ready to try it. <\/p>\n\n\n\n 5. Open main.cpp<\/em>.<\/p>\n\n\n\n On the top, in ‘includes’ section add a new line:<\/p>\n\n\n\n In main(void)<\/em> function, in the very beginning, right after \u201c{\u201c add a new line<\/p>\n\n\n\n Pick Debug <\/strong>configuration.<\/p>\n\n\n\n Build and run (green arrow). Look at Console window:<\/p>\n\n\n\n Hello Windows !<\/strong><\/p>\n\n\n\n 6. Now we can remove \u201c#include <stdio.h>\u201d from main.cpp<\/em> and change error_callback()<\/em> from using printf to mylog <\/em>(it was an only printf occurrence in main.cpp):<\/p>\n\n\n <\/p>\n\n\n\n Build and run – good.<\/p>\n\n\n\n Now – on <\/p>\n\n\n\n On Android it will be a bit different. First \u2013 there is no Console window. Second \u2013 no \u201cwindows\u201d at all (in Windows sense). However, it has \u201cLogCat\u201d – Android\u2019s own mechanism for printing debug\/development messages.<\/p>\n\n\n\n 7. Close and re-start Visual Studio, open C:\\CPP\\a999hello\\p_android\\p_android.sln<\/em>.<\/p>\n\n\n\n 8. Again, need to add a filter (virtual folder): right-click on p_android.NativeActivity<\/em> project -> Add -> New Filter<\/strong><\/em>.<\/p>\n\n\n\n Same name, xPlatform<\/strong><\/p>\n\n\n\n 9. Under xPlatform <\/em>create a header file: Right-click on xPlatform<\/em>, Add -> New Item<\/em>,<\/p>\n\n\n\n Then \u2013 Add<\/strong>.<\/p>\n\n\n\n The code:<\/p>\n\n\n <\/p>\n\n\n\n This code relies on _DEBUG<\/strong> constant, but it is missed in Android’s debug configuration.<\/p>\n\n\n\n 10. Open p_android.NativeApplication<\/em> project properties, pick Debug <\/strong>configuration, ARM64,<\/em> <\/p>\n\n\n\n go to Configuration Properties -> C\/C++ -> Preprocessor<\/em>, open Preprocessor Definitions -> Edit<\/em>. If _DEBUG<\/strong> is missed – add it, then OK, Apply, Ok.<\/p>\n\n\n\n 11. Now open main.cpp<\/em>.<\/p>\n\n\n\n In #include section add a new line:<\/p>\n\n\n\n In android_main (\u2026)<\/em>, in the very beginning, right after \u201c{\u201c add a new line:<\/p>\n\n\n\n <\/p>\n\n\n\n 12. Again, we need to inform p_android.NativeActivity<\/em> project where to look for platform.h<\/em> header.<\/p>\n\n\n\n Right-click on p_android.NativeActivity<\/em> project -> Properties, All Configurations<\/strong>, ARM64<\/em>. Open Configuration Properties -> C\/C++ -> General -> Additional Include Directories -> Edit<\/em>, Add new line, navigate to<\/p>\n\n\n\n C:\\CPP\\p_android<\/em><\/p>\n\n\n\n Select Folder, Ok, Apply, Ok.<\/p>\n\n\n\n 13. Turn on and unlock <\/strong>your Android device, plug it in with USB cable, allow USB Debugging.<\/p>\n\n\n\n 14. Build and run (green arrow). On Android side nothing changed, same green flashing screen, but now we can open LogCat<\/strong>.<\/p>\n\n\n\n 15. On VS screen open top menu -> Tools -> Android Tools -> Logcat<\/em>.<\/p>\n\n\n\n In <Search Logcat> field print \u201cmylog\u201d, Enter. What do we have here?:<\/p>\n\n\n\n Hello Android !<\/strong><\/p>\n\n\n\n VS top menu -> Debug -> Stop Debugging.<\/em> <\/p>\n\n\n\n <\/p>\n","protected":false},"excerpt":{"rendered":" Now, having OpenGL ES projects for 2 different platforms, we can see what is common and what is different. Common is generic structure: Creating GL context, initializing data, main loop with frames rendering, exit. GL calls (Thank God!) look similar too. The difference is in program and GL initialization, in GL-related includes (gl\/egl on Android […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-335","post","type-post","status-publish","format-standard","hentry","category-cross-platform-3d"],"_links":{"self":[{"href":"https:\/\/writingagame.com\/index.php\/wp-json\/wp\/v2\/posts\/335","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/writingagame.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/writingagame.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/writingagame.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/writingagame.com\/index.php\/wp-json\/wp\/v2\/comments?post=335"}],"version-history":[{"count":19,"href":"https:\/\/writingagame.com\/index.php\/wp-json\/wp\/v2\/posts\/335\/revisions"}],"predecessor-version":[{"id":1279,"href":"https:\/\/writingagame.com\/index.php\/wp-json\/wp\/v2\/posts\/335\/revisions\/1279"}],"wp:attachment":[{"href":"https:\/\/writingagame.com\/index.php\/wp-json\/wp\/v2\/media?parent=335"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/writingagame.com\/index.php\/wp-json\/wp\/v2\/categories?post=335"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/writingagame.com\/index.php\/wp-json\/wp\/v2\/tags?post=335"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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\n\n\n\n\n#pragma once\n#include "stdio.h"\n#include <stdarg.h>\n\ninline void mylog(const char* _Format, ...) {\n#ifdef _DEBUG\n va_list _ArgList;\n va_start(_ArgList, _Format);\n vprintf(_Format, _ArgList);\n va_end(_ArgList);\n#endif\n};\n\n<\/pre><\/div>\n\n\n
\n\n\n\n#include \"platform.h\"<\/code><\/pre>\n\n\n\nmylog(\" Hello %s !\\n\", \"Windows\");<\/code><\/pre>\n\n\n\n
\n\n\n\n\nstatic void error_callback(int error, const char* description)\n{\n mylog("Error: %s\\n", description);\n}\n\n<\/pre><\/div>\n\n\n
\n\n\n\nAndroid:<\/h2>\n\n\n\n
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\n\n\n\n\n#pragma once\n#include <android\/log.h>\n#include "stdio.h"\n\ninline void mylog(const char* _Format, ...) {\n#ifdef _DEBUG\n char outStr[1024];\n va_list _ArgList;\n va_start(_ArgList, _Format);\n vsprintf(outStr, _Format, _ArgList);\n __android_log_print(ANDROID_LOG_INFO, "mylog", outStr, NULL);\n va_end(_ArgList);\n#endif\n};\n\n<\/pre><\/div>\n\n\n
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\n\n\n\n#include \"platform.h\"<\/code><\/pre>\n\n\n\nmylog(\" Hello %s ! \\n\", \"Android\");<\/code><\/pre>\n\n\n\n
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