Fixes for Mac App Bundle and OpenGL on macOS

Modifications to pull the data from Application Support in macOS in order to facilitate distribution as a n App Bundle.

Also incorporated code from this unmerged PR to fix issues with OpenGL
Interrupt#409

Author: tomkidd

.gitignore

@@ -58,3 +58,4 @@ savgam*.dat
 # Eclipse CDT
 .project
 .cproject
+.DS_Store

src/GameSrc/setup.c

@@ -1207,7 +1207,13 @@ errtype load_savegame_names(void) {
     for (i = 0; i < NUM_SAVE_SLOTS; i++) {
         Poke_SaveName(i);
 
+#ifdef __APPLE__
+        char full_save_game_name[1024];
+        sprintf(full_save_game_name, "%s%s", SDL_GetPrefPath("Interrupt", "SystemShock"), save_game_name);
+        if (access(full_save_game_name, F_OK) != -1) {
+#else
         if (access(save_game_name, F_OK) != -1) {
+#endif
             file = ResOpenFile(save_game_name);
             if (ResInUse(OLD_SAVE_GAME_ID_BASE)) {
 #ifdef OLD_SG_FORMAT

src/Libraries/RES/Source/caseless.c

@@ -23,6 +23,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <string.h>
 #include <stdio.h>
 #include <sys/stat.h>
+#ifdef __APPLE__
+#include <SDL.h>
+#endif
 
 #ifndef PATH_MAX
 #define PATH_MAX 4096
@@ -245,7 +248,16 @@ FILE *fopen_caseless(const char *path, const char *mode) {
     if (path == NULL || mode == NULL)
         return NULL;
 
+#ifdef __APPLE__
+    char *macpath;
+    const char * prefix = SDL_GetPrefPath("Interrupt", "SystemShock");
+    macpath = (char *)malloc(strlen(prefix) + strlen(path) + 1);
+    strcpy(macpath, prefix);
+    strcpy(&macpath[strlen(prefix)], path);    
+    ret = fopen(macpath, mode);
+#else 
     ret = fopen(path, mode);
+#endif
 
 #ifndef _WIN32 // not windows
     if (ret == NULL) {

src/MacSrc/OpenGL.cc

@@ -184,8 +184,13 @@ static GLuint loadShader(GLenum type, const char *filename) {
 
     DEBUG("Loading shader %s", filename);
 
+#ifdef __APPLE__
+    char fb[1024];
+    sprintf(fb, "%s/shaders/%s", SDL_GetBasePath(), filename);
+#else
     char fb[256];
     sprintf(fb, "shaders/%s", filename);
+#endif
 
     FILE *file = fopen(fb, "r");
     if (file == nullptr) {
@@ -294,6 +299,7 @@ int init_opengl() {
     }
 
     // Can we create the world rendering context?
+    SDL_GL_SetAttribute(SDL_GL_SHARE_WITH_CURRENT_CONTEXT, 1);
     context = SDL_GL_CreateContext(window);
     if (context == nullptr) {
         ERROR("Could not create an OpenGL context! Falling back to Software mode.");
@@ -444,21 +450,21 @@ void get_hdpi_scaling(int *x_scale, int *y_scale) {
     *y_scale = output_height / screen_height;
 }
 
-void opengl_swap_and_restore() {
+void opengl_swap_and_restore(SDL_Surface *ui) {
     // restore the view backup (without HUD overlay) for incremental
     // updates in the subsequent frame
     SDL_GL_MakeCurrent(window, context);
-    SDL_GL_SwapWindow(window);
-
     glClear(GL_COLOR_BUFFER_BIT);
 
     int x_hdpi_scale, y_hdpi_scale;
     get_hdpi_scaling(&x_hdpi_scale, &y_hdpi_scale);
 
+    // Set the drawable area for the 3d view
     glViewport(phys_offset_x * x_hdpi_scale, phys_offset_y * y_hdpi_scale, phys_width * x_hdpi_scale,
                phys_height * y_hdpi_scale);
     set_blend_mode(false);
 
+    // Bind and setup our general shader program
     glUseProgram(textureShaderProgram.shaderProgram);
     GLint tcAttrib = textureShaderProgram.tcAttrib;
     GLint lightAttrib = textureShaderProgram.lightAttrib;
@@ -468,6 +474,7 @@ void opengl_swap_and_restore() {
     glUniformMatrix4fv(textureShaderProgram.uniView, 1, false, IdentityMatrix);
     glUniformMatrix4fv(textureShaderProgram.uniProj, 1, false, IdentityMatrix);
 
+    // Draw the frame buffer to the screen as a quad
     bind_texture(backupBuffer.texture);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
@@ -487,14 +494,25 @@ void opengl_swap_and_restore() {
     glVertex3f(-1.0f, 1.0f, 0.0f);
     glEnd();
 
+    // Finish drawing the 3d view
     glFlush();
 
     glUniform1i(textureShaderProgram.uniNightSight, false);
 
-    // check OpenGL error
+    // Check for OpenGL errors that might have happened
     GLenum err = glGetError();
     if (err != GL_NO_ERROR)
         ERROR("OpenGL error: %i", err);
+
+    // Blit the UI canvas over the 3d view
+    SDL_Texture *texture = SDL_CreateTextureFromSurface(renderer, ui);
+    SDL_SetTextureBlendMode(texture, SDL_BLENDMODE_BLEND);
+
+    SDL_RenderCopy(renderer, texture, NULL, NULL);
+    SDL_DestroyTexture(texture);
+
+    // Finally, swap to the screen
+    SDL_RenderPresent(renderer);
 }
 
 void toggle_opengl() {

src/MacSrc/OpenGL.h

@@ -6,6 +6,7 @@ extern "C" {
 #endif
 
 #include <3d.h>
+#include <SDL.h>
 
 #ifdef USE_OPENGL
 
@@ -18,7 +19,7 @@ bool use_opengl();
 void toggle_opengl();
 void opengl_resize(int width, int height);
 bool should_opengl_swap();
-void opengl_swap_and_restore();
+void opengl_swap_and_restore(SDL_Surface *ui);
 void opengl_change_palette();
 
 void opengl_set_viewport(int x, int y, int width, int height);
@@ -46,7 +47,7 @@ static bool use_opengl() { return false; }
 static void toggle_opengl() {}
 static void opengl_resize(int width, int height) {}
 static bool should_opengl_swap() { return false; }
-static void opengl_swap_and_restore() {}
+static void opengl_swap_and_restore(SDL_Surface *ui) {}
 static void opengl_change_palette() {}
 
 static void opengl_set_viewport(int x, int y, int width, int height) {}

src/MacSrc/Shock.c

@@ -232,7 +232,7 @@ void SetSDLPalette(int index, int count, uchar *pal) {
     static bool gammalut_init = 0;
     static uchar gammalut[100 - 10 + 1][256];
     if (!gammalut_init) {
-        double factor = (can_use_opengl() ? 1.0 : 2.2); // OpenGL uses 2.2
+        double factor = (use_opengl() ? 1.0 : 2.2); // OpenGL uses 2.2
         int i, j;
         for (i = 10; i <= 100; i++) {
             double gamma = (double)i * 1.0 / 100;
@@ -279,26 +279,28 @@ void SetSDLPalette(int index, int count, uchar *pal) {
 
 void SDLDraw() {
     if (should_opengl_swap()) {
+        // We want the UI background to be transparent!
         sdlPalette->colors[255].a = 0x00;
-    }
 
-    SDL_Texture *texture = SDL_CreateTextureFromSurface(renderer, drawSurface);
+        // Draw the OpenGL view
+        opengl_swap_and_restore(drawSurface);
 
-    if (should_opengl_swap()) {
+        // Set the palette back, and we are done
         sdlPalette->colors[255].a = 0xff;
-        SDL_SetTextureBlendMode(texture, SDL_BLENDMODE_BLEND);
+        return;
     }
 
+    // Clear the screen!
+    SDL_RenderClear(renderer);
+    SDL_Texture *texture = SDL_CreateTextureFromSurface(renderer, drawSurface);
+
+    // Blit to the screen by drawing the surface 
     SDL_Rect srcRect = {0, 0, gScreenWide, gScreenHigh};
     SDL_RenderCopy(renderer, texture, &srcRect, NULL);
     SDL_DestroyTexture(texture);
 
-    if (should_opengl_swap()) {
-        opengl_swap_and_restore();
-    } else {
-        SDL_RenderPresent(renderer);
-        SDL_RenderClear(renderer);
-    }
+    // Show everything we've drawn
+    SDL_RenderPresent(renderer);
 }
 
 bool MouseCaptured = FALSE;

src/MusicSrc/MusicDevice.c

@@ -18,6 +18,9 @@
 # include <sys/types.h>
 # include <dirent.h>
 #endif
+#ifdef __APPLE__
+#include <SDL.h>
+#endif
 
 //------------------------------------------------------------------------------
 // Dummy MIDI player
@@ -1023,9 +1026,15 @@ static int FluidMidiInit(MusicDevice *dev, const unsigned int outputIndex, unsig
     fluid_settings_t *settings;
     fluid_synth_t *synth;
     int sfid;
-    char fileName[1024] = "res/";
+#ifdef __APPLE__
+    char fileName[1024] = "";
+    sprintf(fileName, "%sres/", SDL_GetBasePath());
 
+    FluidMidiGetOutputName(dev, outputIndex, &fileName[strlen(fileName)], 1024 - strlen(fileName));
+#else
+    char fileName[1024] = "res/";
     FluidMidiGetOutputName(dev, outputIndex, &fileName[4], 1020);
+#endif
     if (strlen(fileName) == 4)
     {
         WARN("Failed to locate SoundFont for outputIndex=%d", outputIndex);
@@ -1183,8 +1192,14 @@ static unsigned int FluidMidiGetOutputCount(MusicDevice *dev)
         do { ++outputCount; } while (FindNextFile(hFind, &data));
         FindClose(hFind);
     }
+#else
+#ifdef __APPLE__
+    char *respath[1024];
+    sprintf(respath, "%sres/", SDL_GetBasePath());
+    DIR *dirp = opendir(respath);
 #else
     DIR *dirp = opendir("res");
+#endif
     struct dirent *dp = 0;
     while ((dp = readdir(dirp)))
     {
@@ -1237,7 +1252,13 @@ static void FluidMidiGetOutputName(MusicDevice *dev, const unsigned int outputIn
     unsigned int outputCount = 0; // subtract 1 to get index
     // count .sf2 files in res/ subdirectory until we find the one that the user
     //  probably wants
+#ifdef __APPLE__
+    char *respath[1024];
+    sprintf(respath, "%sres/", SDL_GetBasePath());
+    DIR *dirp = opendir(respath);
+#else
     DIR *dirp = opendir("res");
+#endif
     struct dirent *dp = 0;
     while ((outputCount <= outputIndex) &&
            (dp = readdir(dirp)))