attempt to build web version out of emscripten legacy gl wrapper

CMakeLists.txt

@@ -30,15 +30,15 @@ option(TWN_USE_AMALGAM "Enable use of twn_amalgam.c as a single compilation unit
 option(TWN_FEATURE_DYNLIB_GAME "Enable dynamic library loading support" ON)
 set(TWN_OUT_DIR ${CMAKE_SOURCE_DIR} CACHE PATH "Artifact destination")
 
-# todo: figure out how to compile for dynamic linking instead
+# todo: figure out how to compile for dynamic linking instead?
-if(EMSCRIPTEN)
+if(HAIKU OR EMSCRIPTEN)
         if(TWN_FEATURE_DYNLIB_GAME)
                 message(WARNING "TWN_FEATURE_DYNLIB_GAME is set, but not supported - it is turned off")
                 set(TWN_FEATURE_DYNLIB_GAME OFF CACHE INTERNAL "")
         endif()
 endif()
 
-if(HAIKU)
+if(HAIKU OR EMSCRIPTEN)
         if(TWN_SANITIZE)
                 message(WARNING "TWN_SANITIZE is set, but not supported - it is turned off")
                 set(TWN_SANITIZE OFF CACHE INTERNAL "")
@@ -64,11 +64,7 @@ set(PHYSFS_ARCHIVE_7Z OFF CACHE INTERNAL "")
 add_subdirectory(third-party/physfs ${CMAKE_CURRENT_BINARY_DIR}/third-party/physfs SYSTEM)
 add_subdirectory(third-party/libxm ${CMAKE_CURRENT_BINARY_DIR}/third-party/libxm SYSTEM)
 
-if(EMSCRIPTEN)
+set(TWN_RENDERING_API OPENGL_15)
-        set(TWN_RENDERING_API WEBGL1)
-else()
-        set(TWN_RENDERING_API OPENGL_15)
-endif()
 
 if(TWN_RENDERING_API MATCHES OPENGL_15)
         set(SYSTEM_SOURCE_FILES ${SYSTEM_SOURCE_FILES}
@@ -140,7 +136,7 @@ set_target_properties(${TWN_TARGET} PROPERTIES
 # precompile commonly used not-so-small headers
 target_precompile_headers(${TWN_TARGET} PRIVATE
         $<$<NOT:$<BOOL:${EMSCRIPTEN}>>:third-party/glad/include/glad/glad.h>
-        ${SDL2_INCLUDE_DIR}/SDL.h
+        $<$<NOT:$<BOOL:${EMSCRIPTEN}>>:${SDL2_INCLUDE_DIR}/SDL.h>
         third-party/physfs/src/physfs.h)
 
 
@@ -170,6 +166,13 @@ function(give_options_without_warnings target)
 		$<$<BOOL:${TWN_SANITIZE}>:-fstack-protector-all -fsanitize=undefined -fsanitize=address>
                 $<$<BOOL:${EMSCRIPTEN}>:-gsource-map>)
 
+        set(LINK_FLAGS
+                -Bsymbolic-functions
+
+                $<$<BOOL:${EMSCRIPTEN}>:-sLEGACY_GL_EMULATION -sGL_FFP_ONLY -sGL_UNSAFE_OPTS>
+                $<$<NOT:$<BOOL:${EMSCRIPTEN}>>:-Wl,--as-needed>
+                $<$<BOOL:${LINUX}>:-Wl,--hash-style=gnu>)
+
         set(LINK_FLAGS_RELEASE
                 $<$<STREQUAL:${CMAKE_C_COMPILER_ID},Clang>:-Wl,--strip-all>
                 ${BUILD_FLAGS_RELEASE})
@@ -194,12 +197,10 @@ function(give_options_without_warnings target)
 
         target_link_options(${target} PUBLIC
                                       ${BUILD_FLAGS}
+                                      ${LINK_FLAGS}
                                       # -Wl,--no-undefined # TODO: use later for implementing no-libc
                                       $<$<CONFIG:Release>:${LINK_FLAGS_RELEASE}>
-                                      $<$<CONFIG:Debug>:${BUILD_FLAGS_DEBUG}>
+                                      $<$<CONFIG:Debug>:${BUILD_FLAGS_DEBUG}>)
-                                      -Bsymbolic-functions
-                                      -Wl,--as-needed
-                                      $<$<BOOL:${LINUX}>:-Wl,--hash-style=gnu>)
 
         get_target_property(target_type ${target} TYPE)
         if (target_type MATCHES SHARED_LIBRARY)
@@ -274,7 +275,7 @@ endfunction()
 function(link_deps target)
         target_link_libraries(${target} PUBLIC
                                         $<$<NOT:$<BOOL:${EMSCRIPTEN}>>:SDL2::SDL2>
-                                        $<$<NOT:$<BOOL:${TWN_FEATURE_DYNLIB_GAME}>>:SDL2::SDL2main>
+                                        $<$<NOT:$<OR:$<BOOL:${TWN_FEATURE_DYNLIB_GAME}>,$<BOOL:${EMSCRIPTEN}>>>:SDL2::SDL2main>
                                         physfs-static
                                         xms)
 	target_include_directories(${target} PUBLIC ${SDL2_INCLUDE_DIRS})

apps/demos/platformer/CMakeLists.txt

@@ -6,7 +6,7 @@ if(NOT CMAKE_BUILD_TYPE)
         set(CMAKE_BUILD_TYPE Debug)
 endif()
 
-add_subdirectory($ENV{TWNROOT} $ENV{TWNROOT}/build)
+add_subdirectory($ENV{TWNROOT} ${CMAKE_BINARY_DIR}/twn)
 
 set(SOURCE_FILES
         game.c
@@ -20,4 +20,4 @@ set(SOURCE_FILES
         scenes/ingame.c scenes/ingame.h
 )
 
-use_townengine("${SOURCE_FILES}" ${CMAKE_CURRENT_SOURCE_DIR})
+use_townengine("${SOURCE_FILES}" ${TWN_OUT_DIR})

bin/twnbuild

@@ -7,45 +7,56 @@ from pathlib import Path
 from sys import argv
 import tomllib
 
+#TODO: support for default pack override
+#TODO: automatic full rebuild on git head change (such as new commits)
+
 has_ninja = getoutput("command -v ninja") != ""
 has_clang = getoutput("command -v clang") != ""
 
-#TODO: support for default pack override
+target_web = "--target=web" in argv
+
+#TODO: infer what "native" means for current env
+build_dir = "build/web" if target_web else "build/native"
+build_dir += "/release" if "--release" in argv else "/debug"
+
+cmake = ["emcmake", "cmake"] if target_web else ["cmake"]
+# cmake configuration command
+command = []
 
-cmake = ["cmake"]
 # check whether clang is around (it's just better)
 if has_clang:
-    cmake += ["-DCMAKE_C_COMPILER=clang"]
+    command += ["-DCMAKE_C_COMPILER=clang"]
 # check whether ninja is around (you better start running)
 if has_ninja:
-    cmake += ["-G", "Ninja"]
+    command += ["-G", "Ninja"]
-cmake += ["-B", "build"]
+
+command += ["-B", build_dir]
 
 # TODO: have it --fast=1 instead, where separate --debug=0 would mean stripping the debug info
 if "--release" in argv:
-    cmake += ["-DCMAKE_BUILD_TYPE=Release"]
+    command += ["-DCMAKE_BUILD_TYPE=Release"]
 elif "--debug" in argv:
-    cmake += ["-DCMAKE_BUILD_TYPE=Debug"]
+    command += ["-DCMAKE_BUILD_TYPE=Debug"]
 
 if "--unified=1" in argv:
-    cmake += ["-DTWN_FEATURE_DYNLIB_GAME=ON"]
+    command += ["-DTWN_FEATURE_DYNLIB_GAME=ON"]
 elif "--unified=0" in argv:
-    cmake += ["-DTWN_FEATURE_DYNLIB_GAME=OFF"]
+    command += ["-DTWN_FEATURE_DYNLIB_GAME=OFF"]
 
 if "--sanitize=1" in argv:
-    cmake += ["-DTWN_SANITIZE=ON"]
+    command += ["-DTWN_SANITIZE=ON"]
 elif "--sanitize=0" in argv:
-    cmake += ["-DTWN_SANITIZE=OFF"]
+    command += ["-DTWN_SANITIZE=OFF"]
 
-cmake += [f"-DTWN_OUT_DIR={getcwd()}"]
+command += [f"-DTWN_OUT_DIR={getcwd()}"]
 # pass arbitrary arguments over
 if "--" in argv:
-    cmake += argv[argv.index("--")+1:]
+    command += argv[argv.index("--")+1:]
 
 # if no root cmake file is present, infer it from `twn.toml:game.interpreter`
 if not Path("CMakeLists.txt").is_file():
     config = tomllib.loads(Path("data/twn.toml").read_text())
-    cmake += ["-S", expandvars(config["game"]["interpreter"])]
+    command += ["-S", expandvars(config["game"]["interpreter"])]
 
-run(cmake, check=True)
+run(cmake + command, check=True)
-run(["cmake", "--build", "build", "--parallel"], check=True)
+run(["cmake"] + ["--build", build_dir, "--parallel"], check=True)

src/rendering/twn_gl_15_rendering.c

@@ -5,7 +5,13 @@
 #include "twn_types.h"
 #include "twn_deferred_commands.h"
 
+#ifdef EMSCRIPTEN
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glext.h>
+#else
 #include <glad/glad.h>
+#endif
 #include <stb_ds.h>
 
 
@@ -35,13 +41,16 @@ static void APIENTRY opengl_log(GLenum source,
 
 
 bool render_init(void) {
+#ifndef EMSCRIPTEN
     if (gladLoadGLLoader(&SDL_GL_GetProcAddress) == 0) {
         CRY("Init", "GLAD failed");
         return false;
     }
+#endif
 
     log_info("OpenGL context: %s\n", glGetString(GL_VERSION));
 
+#ifndef EMSCRIPTEN
     glHint(GL_TEXTURE_COMPRESSION_HINT, GL_NICEST);
     glHint(GL_GENERATE_MIPMAP_HINT, GL_NICEST);
     glHint(GL_FOG_HINT, GL_FASTEST);
@@ -51,6 +60,7 @@ bool render_init(void) {
         glEnable(GL_DEBUG_OUTPUT);
         glDebugMessageCallback(opengl_log, NULL);
     }
+#endif
 
     return true;
 }
@@ -88,16 +98,21 @@ static void finally_use_space_pipeline(void) {
     depth_range_high = 1.0;
     depth_range_low = 0.0;
 
+#ifndef EMSCRIPTEN
     static GLuint list = 0;
     if (!list) {
         list = glGenLists(1);
 
-        glNewList(list, GL_COMPILE); {
+        glNewList(list, GL_COMPILE);
+#endif
+        {
             glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
             glShadeModel(GL_FLAT);
 
+        #ifndef EMSCRIPTEN
             if (GLAD_GL_ARB_depth_clamp)
                 glDisable(GL_DEPTH_CLAMP);
+        #endif
 
             if (ctx.cull_faces)
                 glEnable(GL_CULL_FACE);
@@ -110,10 +125,12 @@ static void finally_use_space_pipeline(void) {
 
             /* solid white, no modulation */
             glColor4ub(255, 255, 255, 255);
+#ifndef EMSCRIPTEN
         } glEndList();
-    }
 
     glCallList(list);
+#endif
+    }
 
     glMatrixMode(GL_PROJECTION);
     glLoadMatrixf(&camera_projection_matrix.row[0].x);
@@ -135,26 +152,30 @@ static void finally_use_2d_pipeline(void) {
     if (pipeline_last_used == PIPELINE_2D)
         return;
 
+#ifndef EMSCRIPTEN
     static GLuint list = 0;
     if (!list) {
         list = glGenLists(1);
-
         glNewList(list, GL_COMPILE); {
+#endif
             glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST);
             glShadeModel(GL_FLAT);
 
+        #ifndef EMSCRIPTEN
             /* removes near/far plane comparison and discard */
             if (GLAD_GL_ARB_depth_clamp)
                 glEnable(GL_DEPTH_CLAMP);
+        #endif
 
             glEnable(GL_TEXTURE_2D);
             glActiveTexture(GL_TEXTURE0);
             glDisable(GL_CULL_FACE);
             glEnable(GL_DEPTH_TEST);
+#ifndef EMSCRIPTEN
         } glEndList();
-    }
 
-    glCallList(list);
+    } glCallList(list);
+#endif
 
     glMatrixMode(GL_PROJECTION);
     glLoadIdentity();
@@ -180,34 +201,41 @@ static void finally_use_texture_mode(TextureMode mode) {
     if (texture_mode_last_used == mode)
         return;
 
+#ifndef EMSCRIPTEN
     static GLuint lists = 0;
     if (!lists) {
         lists = glGenLists(3);
 
         /* ghostly */
         glNewList(lists + 0, GL_COMPILE); {
+#endif
             glEnable(GL_BLEND);
             glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
             glDepthFunc(GL_LESS);
             glDepthMask(GL_FALSE);
             glDisable(GL_ALPHA_TEST);
+#ifndef EMSCRIPTEN
         } glEndList();
 
         /* seethrough */
         glNewList(lists + 1, GL_COMPILE); {
+#endif
             glDisable(GL_BLEND);
             glDepthFunc(GL_LESS);
             glDepthMask(GL_TRUE);
             glEnable(GL_ALPHA_TEST);
             glAlphaFunc(GL_EQUAL, 1.0f);
+#ifndef EMSCRIPTEN
         } glEndList();
 
         /* opaque */
         glNewList(lists + 2, GL_COMPILE); {
+#endif
             glDisable(GL_BLEND);
             glDepthFunc(GL_LESS);
             glDepthMask(GL_TRUE);
             glDisable(GL_ALPHA_TEST);
+#ifndef EMSCRIPTEN
         } glEndList();
     }
 
@@ -219,6 +247,8 @@ static void finally_use_texture_mode(TextureMode mode) {
         glCallList(lists + 2);
     }
 
+#endif
+
     texture_mode_last_used = mode;
 }
 
@@ -227,7 +257,11 @@ VertexBufferBuilder build_vertex_buffer(VertexBuffer buffer, size_t bytes) {
     SDL_assert(bytes != 0);
     glBindBuffer(GL_ARRAY_BUFFER, buffer);
     glBufferData(GL_ARRAY_BUFFER, bytes, NULL, GL_STREAM_DRAW);
+#ifndef EMSCRIPTEN
     void *mapping = glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY);
+#else
+    void *mapping = SDL_malloc(bytes);
+#endif
     if (!mapping)
         CRY("build_vertex_buffer", "Error mapping a vertex array buffer");
 
@@ -239,8 +273,13 @@ VertexBufferBuilder build_vertex_buffer(VertexBuffer buffer, size_t bytes) {
 
 
 void finish_vertex_builder(VertexBufferBuilder *builder) {
+#ifndef EMSCRIPTEN
     if (!glUnmapBuffer(GL_ARRAY_BUFFER))
         CRY("finish_vertex_builder", "Error unmapping a vertex array buffer");
+#else
+    glBufferData(GL_ARRAY_BUFFER, builder->size, builder->base, GL_STREAM_DRAW);
+    SDL_free(builder->base);
+#endif
     glBindBuffer(GL_ARRAY_BUFFER, 0);
 
     builder->base = 0;
@@ -333,18 +372,23 @@ void finally_render_skybox(DeferredCommandDrawSkybox command) {
     /* TODO: figure out which coordinates to use to not have issues with far z */
     /* TODO: recalculate the list if far z requirement changes */
 
+#ifndef EMSCRIPTEN
     static GLuint list = 0;
     if (!list) {
         list = glGenLists(1);
 
-        glNewList(list, GL_COMPILE); {
+        glNewList(list, GL_COMPILE);
+#endif
+        {
             /* note: assumes that space pipeline is applied already */
             glDisable(GL_ALPHA_TEST);
             glDepthMask(GL_FALSE);
 
+        #ifndef EMSCRIPTEN
             /* removes near/far plane comparison and discard */
             if (GLAD_GL_ARB_depth_clamp)
                 glEnable(GL_DEPTH_CLAMP);
+        #endif
 
             glBegin(GL_QUADS); {
                 /* up */
@@ -408,16 +452,19 @@ void finally_render_skybox(DeferredCommandDrawSkybox command) {
                 glVertex3f(-50.f, 50.f, -50.f);
             } glEnd();
 
+        #ifndef EMSCRIPTEN
             if (GLAD_GL_ARB_depth_clamp)
                 glDisable(GL_DEPTH_CLAMP);
+        #endif
 
             glDepthMask(GL_TRUE);
             glDisable(GL_TEXTURE_CUBE_MAP);
 
+#ifndef EMSCRIPTEN
         } glEndList();
-    }
-
     glCallList(list);
+#endif
+    }
 }
 
 

src/rendering/twn_gl_any_rendering.c

@@ -5,12 +5,13 @@
 #include <stb_ds.h>
 
 #ifdef EMSCRIPTEN
-#include <GLES2/gl2.h>
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glext.h>
 #else
 #include <glad/glad.h>
 #endif
 
-
 void setup_viewport(int x, int y, int width, int height) {
     glViewport(x, y, width, height);
 }
@@ -127,12 +128,7 @@ GPUTexture create_gpu_texture(TextureFilter filter, bool generate_mipmaps, int c
     SDL_assert(width > 0 && height > 0);
     SDL_assert(channels > 0 && channels <= 4);
 
-#if !defined(EMSCRIPTEN)
     glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, (GLboolean)generate_mipmaps);
-#else
-    if (generate_mipmaps)
-        glGenerateMipmap(GL_TEXTURE_2D);
-#endif
 
     if (filter == TEXTURE_FILTER_NEAREAST) {
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
@@ -145,24 +141,14 @@ GPUTexture create_gpu_texture(TextureFilter filter, bool generate_mipmaps, int c
     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 
-#if !defined(EMSCRIPTEN)
     glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
-#endif
 
     int format_internal, format;
     if (channels == 4) {
-        #ifdef EMSCRIPTEN
-        format_internal = GL_RGBA;
-        #else
         format_internal = GL_RGBA8;
-        #endif
         format = GL_RGBA;
     } else if (channels == 3) {
-        #ifdef EMSCRIPTEN
-        format_internal = GL_RGBA;
-        #else
         format_internal = GL_RGBA8;
-        #endif
         format = GL_RGB;
     } else if (channels == 1) {
         format_internal = GL_ALPHA;

src/rendering/twn_text.c

@@ -398,7 +398,4 @@ void finally_draw_text(FontData const *font_data,
     };
 
     arrpush(deferred_commands, final_command);
-
-    /* TODO: why doesn't it get restored if not placed here? */
-    // glDepthMask(GL_TRUE);
 }

src/shell_minimal.html

@@ -127,7 +127,8 @@
         monitorRunDependencies: (left) => {
           this.totalDependencies = Math.max(this.totalDependencies, left);
           Module.setStatus(left ? 'Preparing... (' + (this.totalDependencies-left) + '/' + this.totalDependencies + ')' : 'All downloads complete.');
-        }
+        },
+        GL_MAX_TEXTURE_IMAGE_UNITS = 2
       };
       Module.setStatus('Downloading...');
       window.onerror = () => {

src/twn_filewatch.c

@@ -2,12 +2,12 @@
 #include "twn_util.h"
 #include "twn_engine_context_c.h"
 
+#ifndef EMSCRIPTEN
 #define DMON_IMPL
 #include <dmon.h>
 #include <stb_ds.h>
 #include <SDL2/SDL.h>
 
-
 struct FilewatchEntry {
     char *path;
     FilewatchCallback callback;
@@ -118,3 +118,19 @@ void filewatch_poll(void) {
 
     SDL_UnlockMutex(filewatcher_lock);
 }
+
+#else
+
+bool filewatch_add_directory(char const *dir, FilewatchCallback callback) {
+    (void)dir; (void)callback;
+    return true;
+}
+
+bool filewatch_add_file(char const *filepath, FilewatchCallback callback) {
+    (void)filepath; (void)callback;
+    return true;
+}
+
+void filewatch_poll(void) { (void)0; }
+
+#endif

src/twn_loop.c

@@ -425,11 +425,6 @@ static bool initialize(void) {
     toml_datum_t datum_debug = toml_bool_in(game, "debug");
     ctx.game.debug = datum_debug.ok ? datum_debug.u.b : true;
 
-#ifdef EMSCRIPTEN
-    /* emscripten interpretes those as GL ES version against WebGL */
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2);
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
-#else
     SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 1);
     SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 5);
 
@@ -437,7 +432,6 @@ static bool initialize(void) {
         SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_DEBUG_FLAG);
     else
         SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_NO_ERROR);
-#endif
 
     SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 5);
     SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 6);

src/twn_stb.c

@@ -1,5 +1,7 @@
 /* single compilation unit for every stb implementation */
 
+#include <SDL2/SDL.h>
+
 #include <stdint.h>
 
 #define STB_DS_IMPLEMENTATION