Some basic rendering

Makefile

@@ -22,7 +22,7 @@ RM      := rm -f
 DEBUG   ?= 1
 
 COMMON_CFLAGS  := -std=$(STD) -Werror -Wextra -Wall -MMD -MP -I$(SRC_DIR) `pkg-config --cflags glib-2.0`
-COMMON_LDFLAGS := -std=$(STD) -lm `pkg-config --libs glib-2.0`
+COMMON_LDFLAGS := -std=$(STD) -lm `pkg-config --libs glib-2.0 sdl3 sdl3-image`
 
 ifeq ($(DEBUG),1)
 	COMMON_CFLAGS  += -g -DDEBUG
@@ -32,8 +32,8 @@ else
 endif
 
 
-CLIENT_CFLAGS := $(COMMON_CFLAGS) `pkg-config --cflags sdl3 sdl3-image`
-CLIENT_LDFLAGS := $(COMMON_LDFLAGS) `pkg-config --libs sdl3 sdl3-image`
+CLIENT_CFLAGS := $(COMMON_CFLAGS) # `pkg-config --cflags sdl3`
+CLIENT_LDFLAGS := $(COMMON_LDFLAGS) # `pkg-config --libs sdl3`
 
 SERVER_CFLAGS := $(COMMON_CFLAGS)
 SERVER_LDFLAGS := $(COMMON_LDFLAGS)

src/client/client.c

@@ -31,6 +31,18 @@
 #include <client/gfx_context.h>
 
 static GfxContext *gfx_ctx;
+static World *test_world;
+
+World *
+_make_test_World ()
+{
+  World *self = World_load_from_file ("res/test_map_2.png");
+
+  /* TODO: add players and so on. That will be in GameState,
+     though. Or GameData. */
+
+  return self;
+}
 
 SDL_AppResult
 SDL_AppInit (void **appstate, int argc, char **argv)
@@ -55,6 +67,8 @@ SDL_AppInit (void **appstate, int argc, char **argv)
     }
 
   gfx_ctx = GfxContext_new ();
+  test_world = _make_test_World ();
+  GfxContext_cache_World (gfx_ctx, test_world);
 
   return SDL_APP_CONTINUE;
 }
@@ -78,6 +92,7 @@ SDL_AppIterate (void *appstate)
   UNUSED (appstate);
 
   GfxContext_prerender (gfx_ctx);
+  GfxContext_render_World (gfx_ctx, test_world);
   GfxContext_postrender (gfx_ctx);
 
   return SDL_APP_CONTINUE;

src/client/gfx_context.c

@@ -36,7 +36,7 @@ GfxContext_new ()
 
   self->renderer = SDL_CreateRenderer (self->window, NULL);
 
-  if (!self->window)
+  if (!self->renderer)
     {
       g_critical ("Couldn't create renderer for context %p: %s", self,
 		  SDL_GetError ());
@@ -48,6 +48,7 @@ GfxContext_new ()
 void
 GfxContext_prerender (GfxContext *self)
 {
+  SDL_SetRenderDrawColor (self->renderer, 0, 0, 0, 255);
   SDL_RenderClear (self->renderer);
 }
 
@@ -64,3 +65,75 @@ GfxContext_free (GfxContext *self)
   SDL_DestroyWindow (self->window);
   g_free (self);
 }
+
+void
+GfxContext_cache_World (GfxContext *self, World *world)
+{
+  if (self->world_texture)
+    {
+      SDL_DestroyTexture (self->world_texture);
+    }
+
+  self->world_texture = SDL_CreateTexture (self->renderer,
+					   SDL_PIXELFORMAT_RGBA32,
+					   SDL_TEXTUREACCESS_TARGET,
+					   world->width, world->height);
+
+  if (!self->world_texture)
+    {
+      g_error ("Failed to create world texture: %s", SDL_GetError ());
+    }
+
+  SDL_Texture *old_target = SDL_GetRenderTarget (self->renderer);
+
+  SDL_SetRenderTarget (self->renderer, self->world_texture);
+  SDL_SetRenderDrawColor (self->renderer, 0, 0, 0, 0);
+  SDL_RenderClear (self->renderer);
+
+  for (unsigned int y = 0; y < world->height; ++y)
+    {
+      for (unsigned int x = 0; x < world->width; ++x)
+	{
+	  MapTile *mt =
+	    g_array_index (world->tiles, MapTile *, y * world->width + x);
+
+	  if (!mt)
+	    continue;
+
+	  switch (mt->terrain_type)
+	    {
+	    case TERRAIN_WATER:
+	      SDL_SetRenderDrawColor (self->renderer, 0, 0, 255, 255);
+	      break;
+	    case TERRAIN_FLAT:
+	      SDL_SetRenderDrawColor (self->renderer, 0, 255, 0, 255);
+	      break;
+	    case TERRAIN_HILL:
+	      SDL_SetRenderDrawColor (self->renderer, 0, 127, 0, 255);
+	      break;
+	    default:
+	      SDL_SetRenderDrawColor (self->renderer, 255, 255, 255, 255);
+	      break;
+	    }
+
+	  SDL_RenderPoint (self->renderer, x, y);
+	}
+    }
+
+  SDL_SetRenderTarget (self->renderer, old_target);
+}
+
+void
+GfxContext_render_World (GfxContext *self, World *world)
+{
+  UNUSED (world);
+
+  if (!self->world_texture)
+    {
+      g_warning ("No world texture present");
+      return;
+    }
+
+  SDL_FRect dest = { 0, 0, 800, 600 };
+  SDL_RenderTexture (self->renderer, self->world_texture, NULL, &dest);
+}

src/client/gfx_context.h

@@ -31,6 +31,10 @@ typedef struct GfxContext
 {
   SDL_Window *window;
   SDL_Renderer *renderer;
+
+  SDL_Texture *world_texture;	/* Generated once per every game. */
+  SDL_Texture *player_texture;	/* Probably changes every tick. */
+
 } GfxContext;
 
 GfxContext *GfxContext_new ();
@@ -38,4 +42,5 @@ void GfxContext_prerender (GfxContext * self);
 void GfxContext_postrender (GfxContext * self);
 void GfxContext_free (GfxContext * self);
 
-void GfxContext_renderWorld (GfxContext * self, World * world);
+void GfxContext_cache_World (GfxContext * self, World * world);
+void GfxContext_render_World (GfxContext * self, World * world);

src/common/game_state.c

@@ -1 +1 @@
-#include "game_state.h"
+#include <common/game_state.h>

src/common/game_state.h

@@ -1,12 +1,9 @@
 #pragma once
 
-/* This houses the state of an actual, running game; your player, the
-   other players, the world map, buildings. */
-
 #include <glib-2.0/glib.h>
 #include <SDL3/SDL.h>
 
-#include "world.h"
+#include <common/world.h>
 
 typedef struct Player
 {
@@ -24,5 +21,6 @@ typedef struct GameState
 {
   World *world;
   GArray *players;
-  Player *me;
+
+  gboolean has_started:1;
 } GameState;

src/common/world.c

@@ -1 +1,91 @@
-#include "world.h"
+#include <common/world.h>
+
+static inline Uint32
+_surf_pixel (SDL_Surface *surface, int x, int y)
+{
+  int bpp = SDL_BYTESPERPIXEL (surface->format);
+  Uint8 *p = (Uint8 *) surface->pixels + y * surface->pitch + x * bpp;
+
+  switch (bpp)
+    {
+    case 1:
+      return *p;
+    case 2:
+      return *(Uint16 *) p;
+    case 3:
+      if (SDL_BYTEORDER == SDL_BIG_ENDIAN)
+	{
+	  return p[0] << 16 | p[1] << 8 | p[2];
+	}
+      else
+	{
+	  return p[0] | p[1] << 8 | p[2] << 16;
+	}
+    case 4:
+      return *(Uint32 *) p;
+    default:
+      return 0;			// shouldn't happen
+    }
+}
+
+World *
+World_load_from_file (const char *path)
+{
+  World *self = g_new0 (World, 1);
+  self->buildings = g_array_new (FALSE, FALSE, sizeof (Building *));
+
+  SDL_Surface *surf = IMG_Load (path);
+
+  if (!surf)
+    {
+      g_warning ("Failed to load map from path %s (returning NULL): %s", path,
+		 SDL_GetError ());
+      return NULL;
+    }
+
+  self->width = surf->w;
+  self->height = surf->h;
+  self->tiles =
+    g_array_sized_new (FALSE, FALSE, sizeof (MapTile *), surf->w * surf->h);
+
+  SDL_LockSurface (surf);
+  const SDL_PixelFormatDetails *details =
+    SDL_GetPixelFormatDetails (surf->format);
+
+  for (int y = 0; y < surf->h; ++y)
+    {
+      for (int x = 0; x < surf->w; ++x)
+	{
+	  MapTile *mt = g_new0 (MapTile, 1);
+	  mt->x = x;
+	  mt->y = y;
+
+	  Uint32 pixel = _surf_pixel (surf, x, y);
+	  Uint8 r, g, b, a;
+	  /* NULL is a palette, only used in indexed images. */
+	  SDL_GetRGBA (pixel, details, NULL, &r, &g, &b, &a);
+
+	  /* The ranges here can be tweaked to work better or
+	     worse. */
+	  if (b > 196 && r < 50 && g < 50)
+	    {
+	      mt->terrain_type = TERRAIN_WATER;
+	    }
+	  else if (g > 200)
+	    {
+	      mt->terrain_type = TERRAIN_FLAT;
+	    }
+	  else
+	    {
+	      mt->terrain_type = TERRAIN_HILL;
+	    }
+
+	  g_array_append_val (self->tiles, mt);
+	}
+    }
+
+  SDL_UnlockSurface (surf);
+  SDL_DestroySurface (surf);
+
+  return self;
+}

src/common/world.h

@@ -1,5 +1,8 @@
 #pragma once
 
+#include <SDL3/SDL.h>
+#include <SDL3_image/SDL_image.h>
+
 #include <glib-2.0/glib.h>
 
 typedef enum TerrainType
@@ -26,15 +29,13 @@ typedef struct World
   GArray *buildings;
 } World;
 
-
-typedef struct Building Building;	// Typedef is needed to avoid circular dependency
-struct Building
+typedef struct Building
 {
   MapTile *parent_tile;
   unsigned int level;
 
-  unsigned int (*at_what_cost) (Building * self, World * world);
-};
+  unsigned int (*at_what_cost) (struct Building * self, World * world);
+} Building;
 
-World *World_new (unsigned int width, unsigned int height);
+World *World_load_from_file (const char *path);
 void World_tick (World * self);