Prepare for texture streaming and locking.

The intention is to static stream the gui areas into one big texture.

src/texture.c

@@ -20,6 +20,7 @@
 #include <stdio.h>
 #include <physfs.h>
 #include <stdlib.h>
+#include <assert.h>
 #include "texture.h"
 #include "util.h"
 #include "io_util.h"
@@ -34,9 +35,40 @@ texture_create(void)
 	t->font = NULL;
 	t->lastAccess = SDL_GetTicks();
 	t->path = "";
+	t->textureAccessType = SDL_TEXTUREACCESS_STATIC;
+	t->locked = false;
 	return t;
 }
 
+void
+texture_create_blank(Texture *t,
+		     SDL_TextureAccess access,
+		     SDL_Renderer *renderer)
+{
+	t->texture = SDL_CreateTexture(renderer,
+				       SDL_PIXELFORMAT_RGBA8888,
+				       access,
+				       t->dim.width,
+				       t->dim.height);
+	t->textureAccessType = access;
+}
+
+void
+texture_lock(Texture *t, SDL_Rect *rect, void **pixels, int *pitch)
+{
+	assert (!t->locked);
+	t->locked = true;
+	SDL_LockTexture(t->texture, rect, pixels, pitch);
+}
+
+void
+texture_unlock(Texture *t)
+{
+	assert (t->locked);
+	t->locked = false;
+	SDL_UnlockTexture(t->texture);
+}
+
 void
 texture_load_from_file(Texture *texture,
 		       const char *path,

src/texture.h

@@ -31,11 +31,24 @@ typedef struct {
 	Dimension dim;
 	const char *path;
 	unsigned long lastAccess;
+	SDL_TextureAccess textureAccessType;
+	bool locked;
 } Texture;
 
 Texture*
 texture_create(void);
 
+void
+texture_create_blank(Texture *t,
+					 SDL_TextureAccess,
+					 SDL_Renderer*);
+
+void
+texture_lock(Texture*, SDL_Rect*, void **pixels, int *pitch);
+
+void
+texture_unlock(Texture*);
+
 void
 texture_load_from_file(Texture*, const char *path, SDL_Renderer*);