/** bezier curve algorithm **/
static void
bezier_point(VALUE points, float u, float * x, float * y, int n, int format,
int draw_offset_x, int draw_offset_y)
{
int xy_index;
double sumx = 0, sumy = 0;
for(int k = 0; k < n; k++) {
switch(format) {
case POINT_FORMAT:
sumx += NUM2DBL(point_x(get_from_array(points, k))) * bernstein(n - 1, k, u);
sumy += NUM2DBL(point_y(get_from_array(points, k))) * bernstein(n - 1, k, u);
break;
case SIMPLE_FORMAT:
xy_index = k * 2;
sumx += NUM2DBL(get_from_array(points, xy_index)) * bernstein(n - 1, k, u);
sumy += NUM2DBL(get_from_array(points, xy_index + 1)) * bernstein(n - 1, k, u);
break;
default:
rb_raise(rb_eArgError, "pixel format must be either POINT_FORMAT or SIMPLE_FORMAT");
}
}
*x = sumx + draw_offset_x;
*y = sumy + draw_offset_y;
}
static void
process_x_y_pairs(VALUE image, int num_pairs, VALUE * argv, ...)
{
va_list ap;
int i;
int draw_offset_x;
int draw_offset_y;
VALUE offset_val;
offset_val = get_image_local(image, DRAW_OFFSET);
draw_offset_x = NUM2INT(get_from_array(offset_val, 0));
draw_offset_y = NUM2INT(get_from_array(offset_val, 1));
va_start(ap, argv);
if(is_a_point(argv[0])) {
for(i = 0; i < num_pairs; i++) {
int *x_ptr, *y_ptr;
x_ptr = va_arg(ap, int*);
y_ptr = va_arg(ap, int*);
*x_ptr = NUM2INT(rb_funcall(argv[i], rb_intern("x"), 0)) + draw_offset_x;
*y_ptr = NUM2INT(rb_funcall(argv[i], rb_intern("y"), 0)) + draw_offset_y;
}
}
else {
for(i = 0; i < (num_pairs * 2); i+=2) {
bool
is_rb_raw_color(VALUE cval)
{
return TYPE(cval) == T_ARRAY &&
is_a_num(get_from_array(cval, 0)) &&
is_a_num(get_from_array(cval, 1)) &&
is_a_num(get_from_array(cval, 2)) &&
is_a_num(get_from_array(cval, 3));
}
rgba
convert_image_local_color_to_rgba(VALUE image)
{
rgba color;
VALUE image_local_color = get_image_local(image, IMAGE_COLOR);
color.red = NUM2DBL(get_from_array(image_local_color, red));
color.green = NUM2DBL(get_from_array(image_local_color, green));
color.blue = NUM2DBL(get_from_array(image_local_color, blue));
color.alpha = NUM2DBL(get_from_array(image_local_color, alpha));
return color;
}
void
update_lazy_bounds(action_struct * cur, texture_info * tex)
{
/* only update global bounds if we're doing a lazy_sync */
if (cur->sync_mode != lazy_sync)
return;
VALUE lazy_bounds;
int xmin, ymin, xmax, ymax;
lazy_bounds = get_image_local(tex->image, LAZY_BOUNDS);
xmin = INT2FIX(MIN(cur->xmin, FIX2INT(get_from_array(lazy_bounds, 0))));
ymin = INT2FIX(MIN(cur->ymin, FIX2INT(get_from_array(lazy_bounds, 1))));
xmax = INT2FIX(MAX(cur->xmax, FIX2INT(get_from_array(lazy_bounds, 2))));
ymax = INT2FIX(MAX(cur->ymax, FIX2INT(get_from_array(lazy_bounds, 3))));
set_array_value(lazy_bounds, 0, xmin);
set_array_value(lazy_bounds, 1, ymin);
set_array_value(lazy_bounds, 2, xmax);
set_array_value(lazy_bounds, 3, ymax);
}
static void
process_select_color_list(rgba_list * clist, VALUE try_color)
{
/* is a general array of colors? i.e [:red, Gosu::Color::RED, [1,1,1,1] ] */
if (TYPE(try_color) == T_ARRAY && not_rb_raw_color(try_color)) {
int num_colors = RARRAY_LEN(try_color);
if (num_colors > RGBA_LIST_SIZE)
rb_raise(rb_eArgError, "Too many colors given in array. Maximum is %d\n. Got %d\n",
RGBA_LIST_SIZE, num_colors);
for (int i = 0; i < RARRAY_LEN(try_color); ++i) {
clist->colors[i] = convert_rb_color_to_rgba(get_from_array(try_color, i));
}
clist->size = num_colors;
}
/* is a single color value? i.e :red, [1,1,1,1], Gosu::Color::GREEN */
else {
clist->colors[0] = convert_rb_color_to_rgba(try_color);
clist->size = 1;
}
}
bool
not_rb_raw_color(VALUE cval)
{
return TYPE(cval) != T_ARRAY ||
!is_a_num(get_from_array(cval, 0));
}
VALUE
get_image_local(VALUE image, int name)
{
VALUE image_local;
VALUE val;
init_image_local(image);
/* this var holds all the image local variables in an array */
image_local = rb_iv_get(image, "__image_local__");
/* a particular image_local variable */
val = get_from_array(image_local, name);
/* if the variable exists then return it */
if(!NIL_P(val))
return val;
/* otherwise initialize the variable and then return it */
else {
switch(name) {
VALUE init_offset, init_bounds, init_color, init_defaults;
case DRAW_OFFSET:
init_offset = rb_ary_new2(2);
set_array_value(init_offset, 0, INT2FIX(0));
set_array_value(init_offset, 1, INT2FIX(0));
set_array_value(image_local, DRAW_OFFSET, init_offset);
return init_offset;
break;
case LAZY_BOUNDS:
init_bounds = rb_ary_new2(4);
set_array_value(init_bounds, 0, INT2FIX(XMAX_OOB));
set_array_value(init_bounds, 1, INT2FIX(YMAX_OOB));
set_array_value(init_bounds, 2, INT2FIX(XMIN_OOB));
set_array_value(init_bounds, 3, INT2FIX(YMIN_OOB));
set_array_value(image_local, LAZY_BOUNDS, init_bounds);
return init_bounds;
break;
case IMAGE_COLOR:
init_color = rb_ary_new2(4);
set_array_value(init_color, 0, rb_float_new(1.0));
set_array_value(init_color, 1, rb_float_new(1.0));
set_array_value(init_color, 2, rb_float_new(1.0));
set_array_value(init_color, 3, rb_float_new(1.0));
set_array_value(image_local, IMAGE_COLOR, init_color);
return init_color;
break;
case USER_DEFAULTS:
init_defaults = rb_hash_new();
set_array_value(image_local, USER_DEFAULTS, init_defaults);
return init_defaults;
break;
default:
rb_raise(rb_eArgError, "unrecognized image_local variable number. got %d", name);
}
}
/* never reached */
return Qnil;
}
void
bezier_do_action(VALUE points, texture_info * tex, VALUE hash_arg, texplay_sync sync_mode,
bool primary, action_struct * payload)
{
float u = 0.0;
action_struct cur;
float x1, y1, x2, y2;
int first_x, first_y;
int format;
int num_point_pairs;
bool closed = false;
VALUE offset_val;
int draw_offset_x, draw_offset_y;
/* defaults to 200 (1 / 0.005) samples per curve */
float step_size = 0.005;
draw_prologue(&cur, tex, XMAX_OOB, YMAX_OOB, XMIN_OOB, YMIN_OOB, &hash_arg, sync_mode, primary, &payload);
/* calculate offset */
offset_val = get_image_local(tex->image, DRAW_OFFSET);
draw_offset_x = NUM2INT(get_from_array(offset_val, 0));
draw_offset_y = NUM2INT(get_from_array(offset_val, 1));
if(is_a_hash(hash_arg)) {
/* if the polyline is 'closed' make the last point the first */
if(RTEST(get_from_hash(hash_arg, "closed")) || RTEST(get_from_hash(hash_arg, "close"))) {
/* so that our additional point is not persistent */
points = rb_obj_dup(points);
closed = true;
}
/* number of points to sample */
if(RTEST(get_from_hash(hash_arg, "sample_size"))) {
VALUE c = get_from_hash(hash_arg, "sample_size");
Check_Type(c, T_FIXNUM);
step_size = 1.0 / (float)FIX2INT(c);
}
}
if(is_a_point(get_from_array(points, 0))) {
format = POINT_FORMAT;
if(closed)
rb_ary_push(points, get_from_array(points, 0));
num_point_pairs = RARRAY_LEN(points);
}
else {
format = SIMPLE_FORMAT;
/* ensure points are given in pairs */
if(RARRAY_LEN(points) % 2)
rb_raise(rb_eArgError, "bezier needs an even number of points. got %d\n", (int)RARRAY_LEN(points));
if(closed) {
rb_ary_push(points, get_from_array(points, 0));
rb_ary_push(points, get_from_array(points, 1));
}
num_point_pairs = RARRAY_LEN(points) / 2;
}
if(num_point_pairs > 17)
rb_raise(rb_eArgError, "too many points for bezier curve. 17 points is current maximum. got %d\n",
num_point_pairs);
/* get the first point */
bezier_point(points, 0, &x1, &y1, num_point_pairs, format, draw_offset_x, draw_offset_y);
/* save it so we can link up with last point properly if the curve is 'closed' */
first_x = x1;
first_y = y1;
while(u <= 1) {
bezier_point(points, u, &x2, &y2, num_point_pairs, format, draw_offset_x, draw_offset_y);
line_do_action(x1, y1, x2, y2, tex, hash_arg, no_sync, false, payload);
/* update drawing rectangle */
update_bounds(payload, x1, y1, x2, y2);
x1 = x2;
y1 = y2;
u += step_size;
}
/* sometimes beziers dont close properly, so we'll ensure it's closed */
if(closed)
line_do_action(x2, y2, first_x, first_y, tex, hash_arg, no_sync, false, payload);
draw_epilogue(&cur, tex, primary);
}
trace_match
line_do_action(int x1, int y1, int x2, int y2, texture_info * tex, VALUE hash_arg,
texplay_sync sync_mode, bool primary, action_struct * payload)
{
int x, y, W, H, F;
int xinc, yinc;
action_struct cur;
int thickness = 1;
bool has_trace = false;
rgba trace_color;
trace_mode_type trace_mode = no_mode;
if(has_optional_hash_arg(hash_arg, "thickness"))
thickness = NUM2INT(get_from_hash(hash_arg, "thickness"));
if(has_optional_hash_arg(hash_arg, "trace") && primary) {
VALUE trace_hash = get_from_hash(hash_arg, "trace");
/* we're tracing (not drawing) */
has_trace = true;
/* since we're not drawing, no need to sync */
sync_mode = no_sync;
if(has_optional_hash_arg(trace_hash, "until_color")) {
VALUE c = get_from_hash(trace_hash, "until_color");
trace_color = convert_rb_color_to_rgba(c);
trace_mode = until_color;
}
else if(has_optional_hash_arg(trace_hash, "while_color")) {
VALUE c = get_from_hash(trace_hash, "while_color");
trace_color = convert_rb_color_to_rgba(c);
trace_mode = while_color;
}
}
draw_prologue(&cur, tex, x1, y1,
x2, y2, &hash_arg, sync_mode, primary, &payload);
/* clip the line */
cohen_sutherland_clip(&x1, &y1, &x2, &y2, 0, 0, tex->width - 1, tex->height - 1);
W = ABS(x2 - x1);
H = ABS(y2 - y1);
if(x1 < x2)
xinc = 1;
else
xinc = -1;
if(y1 < y2)
yinc = 1;
else
yinc = -1;
x = x1;
y = y1;
if(W >= H) {
F = 2 * H - W;
while(x != x2) {
if(thickness <= 1) {
if(!has_trace)
set_pixel_color_with_style(payload, tex, x, y);
else {
rgba c = get_pixel_color(tex, x, y);
if (is_trace_match(payload, c, trace_color, trace_mode))
return (trace_match) { x, y, c };
}
}
else {
set_hash_value(hash_arg, "fill", Qtrue);
circle_do_action(x, y, thickness / 2, tex, hash_arg, no_sync, false, payload);
}
if(F < 0)
F += 2 * H;
else {
F += 2 * (H - W);
y += yinc;
}
x += xinc;
}
}
else {
F = 2 * W - H;
while(y != y2 ) {
if(thickness <= 1) {
if(!has_trace)
set_pixel_color_with_style(payload, tex, x, y);
else {
rgba c = get_pixel_color(tex, x, y);
if (is_trace_match(payload, c, trace_color, trace_mode))
return (trace_match) { x, y, c };
}
}
else {
set_hash_value(hash_arg, "fill", Qtrue);
circle_do_action(x, y, thickness / 2, tex, hash_arg, no_sync, false, payload);
}
if(F < 0)
F += 2 * W;
else {
F += 2 * (W - H);
x += xinc;
}
y += yinc;
}
}
if(thickness <= 1) {
if(!has_trace)
set_pixel_color_with_style(payload, tex, x2, y2);
else {
rgba c = get_pixel_color(tex, x, y);
if (is_trace_match(payload, c, trace_color, trace_mode))
return (trace_match) { x, y, c };
}
}
else {
set_hash_value(hash_arg, "fill", Qtrue);
circle_do_action(x2, y2, thickness / 2, tex, hash_arg, no_sync, false, payload);
}
draw_epilogue(&cur, tex, primary);
return (trace_match) { .x = -9999, .y = -9999, .color = not_a_color_v };
}
/** end line **/
/** polyline algorithm **/
/* used by both polyline and bezier */
#define SIMPLE_FORMAT 0
#define POINT_FORMAT 1
/* calculate a single point */
static void
polyline_point(VALUE points, int k, int * x, int * y, int format, int draw_offset_x,
int draw_offset_y)
{
int xy_index;
switch(format) {
case POINT_FORMAT:
*x = NUM2INT(point_x(get_from_array(points, k))) + draw_offset_x;
*y = NUM2INT(point_y(get_from_array(points, k))) + draw_offset_y;
break;
case SIMPLE_FORMAT:
xy_index = k * 2;
*x = NUM2INT(get_from_array(points, xy_index)) + draw_offset_x;
*y = NUM2INT(get_from_array(points, xy_index + 1)) + draw_offset_y;
break;
default:
rb_raise(rb_eArgError, "pixel format must be either POINT_FORMAT or SIMPLE_FORMAT");
}
}
void
polyline_do_action(VALUE points, texture_info * tex, VALUE hash_arg,
texplay_sync sync_mode, bool primary, action_struct * payload)
{
int x1, y1, x2, y2;
int format;
int num_point_pairs;
int k;
int draw_offset_y, draw_offset_x;
action_struct cur;
VALUE offset_val;
bool closed = false;
draw_prologue(&cur, tex, XMAX_OOB, YMAX_OOB, XMIN_OOB, YMIN_OOB, &hash_arg, sync_mode, primary, &payload);
/* calculate offset */
offset_val = get_image_local(tex->image, DRAW_OFFSET);
draw_offset_x = NUM2INT(get_from_array(offset_val, 0));
draw_offset_y = NUM2INT(get_from_array(offset_val, 1));
/* if the polyline is 'closed' make the last point the first */
if(is_a_hash(hash_arg))
if(RTEST(get_from_hash(hash_arg, "closed")) || RTEST(get_from_hash(hash_arg, "close"))) {
/* so that our additional point is not persistent */
points = rb_obj_dup(points);
closed = true;
}
/* determine format of points */
if(is_a_point(get_from_array(points, 0))) {
format = POINT_FORMAT;
/* if the polyline is closed to form a polygon then make the last point and first point identical */
if(closed)
rb_ary_push(points, get_from_array(points, 0));
num_point_pairs = RARRAY_LEN(points);
}
else {
format = SIMPLE_FORMAT;
/* ensure there is an 'x' for every 'y' */
if(RARRAY_LEN(points) % 2)
rb_raise(rb_eArgError, "polyline needs an even number of points. got %d\n",
(int)RARRAY_LEN(points));
if(closed) {
rb_ary_push(points, get_from_array(points, 0));
rb_ary_push(points, get_from_array(points, 1));
}
num_point_pairs = RARRAY_LEN(points) / 2;
}
/* calculate first point */
polyline_point(points, 0, &x1, &y1, format, draw_offset_x, draw_offset_y);
/* calc the points and draw the polyline */
for(k = 1; k < num_point_pairs; k++) {
polyline_point(points, k, &x2, &y2, format, draw_offset_x, draw_offset_y);
line_do_action(x1, y1, x2, y2, tex, hash_arg, no_sync, false, payload);
/* update drawing rectangle */
update_bounds(payload, x1, y1, x2, y2);
x1 = x2; y1 = y2;
}
draw_epilogue(&cur, tex, primary);
}