/**
* =========================================================================
* File : cursor.cpp
* Project : 0 A.D.
* Description : mouse cursors (either via OpenGL texture or hardware)
* =========================================================================
*/
// license: GPL; see lib/license.txt
#include "precompiled.h"
#include "cursor.h"
#include <string.h>
#include <sstream>
// On Windows, allow runtime choice between system cursors and OpenGL
// cursors (Windows = more responsive, OpenGL = more consistent with what
// the game sees)
#if OS_WIN
#define ALLOW_SYS_CURSOR 1
#else
#define ALLOW_SYS_CURSOR 0
#endif
#include "lib/ogl.h"
#include "lib/sysdep/sysdep.h" // sys_cursor_*
#include "lib/res/res.h"
#include "ogl_tex.h"
/*
This is used to create the sys cursor to use together with the OpenGL
cursor. I.e. to set a transparent cursor on X-windows where we don't use
the X11 cursor, and on windows should the hardware cursor setup fail.
Shouldn't be called when both hardware/software cursor fails (i.e. invalid
cursor file given) - in that case we'd rather use the default cursor.
*/
static void *load_empty_sys_cursor()
{
void *sys_cursor = 0;
if(sys_cursor_create_empty(&sys_cursor) < 0)
{
debug_warn("sys_cursor_create_empty failed");
return NULL;
}
return sys_cursor;
}
static void* load_sys_cursor(const char* filename, int hx, int hy)
{
#if !ALLOW_SYS_CURSOR
UNUSED2(filename);
UNUSED2(hx);
UNUSED2(hy);
return 0;
#else
Tex t;
if(tex_load(filename, &t) < 0)
return 0;
{
void* sys_cursor = 0; // return value
// convert to required BGRA format.
const uint flags = (t.flags | TEX_BGR) & ~TEX_DXT;
if(tex_transform_to(&t, flags) < 0)
goto fail;
void* bgra_img = tex_get_data(&t);
if(!bgra_img)
goto fail;
if(sys_cursor_create(t.w, t.h, bgra_img, hx, hy, &sys_cursor) < 0)
goto fail;
(void)tex_free(&t);
return sys_cursor;
}
fail:
debug_warn("failed");
(void)tex_free(&t);
return 0;
#endif
}
// no init is necessary because this is stored in struct Cursor, which
// is 0-initialized by h_mgr.
class GLCursor
{
Handle ht;
uint w, h;
uint hotspotx, hotspoty;
public:
LibError create(const char* filename, uint hotspotx_, uint hotspoty_)
{
ht = ogl_tex_load(filename);
RETURN_ERR(ht);
(void)ogl_tex_get_size(ht, &w, &h, 0);
hotspotx = hotspotx_; hotspoty = hotspoty_;
(void)ogl_tex_set_filter(ht, GL_NEAREST);
(void)ogl_tex_upload(ht);
return INFO::OK;
}
void destroy()
{
// note: we're stored in a resource => ht is initially 0 =>
// this is safe, no need for an is_valid flag
(void)ogl_tex_free(ht);
}
void draw(uint x, uint y) const
{
(void)ogl_tex_bind(ht);
glEnable(GL_TEXTURE_2D);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glEnable(GL_BLEND);
glDisable(GL_DEPTH_TEST);
glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
// OpenGL's coordinate system is "upside-down"; correct for that.
y = g_yres -y;
glBegin(GL_QUADS);
glTexCoord2i(0, 0); glVertex2i( x-hotspotx, y+hotspoty );
glTexCoord2i(1, 0); glVertex2i( x-hotspotx+w, y+hotspoty );
glTexCoord2i(1, 1); glVertex2i( x-hotspotx+w, y+hotspoty-h );
glTexCoord2i(0, 1); glVertex2i( x-hotspotx, y+hotspoty-h );
glEnd();
}
LibError validate() const
{
const uint A = 128; // no cursor is expected to get this big
if(w > A || h > A || hotspotx > A || hotspoty > A)
WARN_RETURN(ERR::_1);
if(ht < 0)
WARN_RETURN(ERR::_2);
return INFO::OK;
}
};
struct Cursor
{
void* sys_cursor;
// valid iff sys_cursor == 0.
GLCursor gl_cursor;
// a system cursor to use together with the gl_cursor
void *gl_sys_cursor;
};
H_TYPE_DEFINE(Cursor);
static void Cursor_init(Cursor* UNUSED(c), va_list UNUSED(args))
{
}
static void Cursor_dtor(Cursor* c)
{
// (note: these are safe, no need for an is_valid flag)
if(c->sys_cursor)
WARN_ERR(sys_cursor_free(c->sys_cursor));
else
c->gl_cursor.destroy();
}
static LibError Cursor_reload(Cursor* c, const char* name, Handle)
{
char filename[PATH_MAX];
// read pixel offset of the cursor's hotspot [the bit of it that's
// drawn at (g_mouse_x,g_mouse_y)] from file.
uint hotspotx = 0, hotspoty = 0;
{
snprintf(filename, ARRAY_SIZE(filename), "art/textures/cursors/%s.txt", name);
FileIOBuf buf; size_t size;
RETURN_ERR(vfs_load(filename, buf, size));
std::stringstream s(std::string((const char*)buf, size));
s >> hotspotx >> hotspoty;
(void)file_buf_free(buf);
}
// load actual cursor
snprintf(filename, ARRAY_SIZE(filename), "art/textures/cursors/%s.dds", name);
// .. try loading as system cursor (2d, hardware accelerated)
c->sys_cursor = load_sys_cursor(filename, hotspotx, hotspoty);
// .. fall back to GLCursor (system cursor code is disabled or failed)
if(!c->sys_cursor)
{
LibError err=c->gl_cursor.create(filename, hotspotx, hotspoty);
if (err == INFO::OK)
c->gl_sys_cursor = load_empty_sys_cursor();
return err;
}
return INFO::OK;
}
static LibError Cursor_validate(const Cursor* c)
{
// note: system cursors have no state to speak of, so we don't need to
// validate them.
if(!c->sys_cursor)
RETURN_ERR(c->gl_cursor.validate());
return INFO::OK;
}
static LibError Cursor_to_string(const Cursor* c, char* buf)
{
const char* type = c->sys_cursor? "sys" : "gl";
snprintf(buf, H_STRING_LEN, "(%s)", type);
return INFO::OK;
}
// note: these standard resource interface functions are not exposed to the
// caller. all we need here is storage for the sys_cursor / GLCursor and
// a name -> data lookup mechanism, both provided by h_mgr.
// in other words, we continually create/free the cursor resource in
// cursor_draw and trust h_mgr's caching to absorb it.
static Handle cursor_load(const char* name)
{
return h_alloc(H_Cursor, name, 0);
}
static LibError cursor_free(Handle& h)
{
return h_free(h, H_Cursor);
}
// draw the specified cursor at the given pixel coordinates
// (origin is top-left to match the windowing system).
// uses a hardware mouse cursor where available, otherwise a
// portable OpenGL implementation.
LibError cursor_draw(const char* name, int x, int y)
{
// Use 'null' to disable the cursor
if(!name)
{
WARN_ERR(sys_cursor_set(0));
return INFO::OK;
}
Handle hc = cursor_load(name);
H_DEREF(hc, Cursor, c);
if(c->sys_cursor)
WARN_ERR(sys_cursor_set(c->sys_cursor));
else
{
c->gl_cursor.draw(x, y);
// Here, gl_sys_cursor is either a pointer to a valid cursor or NULL.
// It is NULL if the gl_cursor init failed or if load_empty_sys_cursor
// failed - in the first case, we want to use the default system cursor,
// in the second case setting the default cursor yields no change.
WARN_ERR(sys_cursor_set(c->gl_sys_cursor));
}
(void)cursor_free(hc);
return INFO::OK;
}