static void dt_guides_draw_harmonious_triangles(cairo_t *cr, const float left, const float top, const float width,
const float height/*, const float dst*/)
{
int dst = (int)((height * cos(atan(width / height)) / (cos(atan(height / width)))));
dt_draw_line(cr, -width / 2, -height / 2, width / 2, height / 2);
dt_draw_line(cr, -width / 2 + dst, -height / 2, -width / 2, height / 2);
dt_draw_line(cr, width / 2, -height / 2, width / 2 - dst, height / 2);
}
void
dt_guides_draw_rules_of_thirds(cairo_t *cr, const float left, const float top, const float right, const float bottom, const float xThird, const float yThird)
{
dt_draw_line(cr, left + xThird, top, left + xThird, bottom);
dt_draw_line(cr, left + 2*xThird, top, left + 2*xThird, bottom);
dt_draw_line(cr, left, top + yThird, right, top + yThird);
dt_draw_line(cr, left, top + 2*yThird, right, top + 2*yThird);
}
void
dt_guides_draw_harmonious_triangles(cairo_t *cr, const float left, const float top, const float right, const float bottom, const float dst)
{
float width, height;
width = right - left;
height = bottom - top;
dt_draw_line(cr, -width/2, -height/2, width/2, height/2);
dt_draw_line(cr, -width/2+dst, -height/2, -width/2, height/2);
dt_draw_line(cr, width/2, -height/2, width/2-dst, height/2);
}
static void dt_guides_draw_rules_of_thirds(cairo_t *cr, const float left, const float top,
const float width, const float height)
{
const float right = left + width, bottom = top + height;
const float x_3 = width / 3.0, y_3 = height / 3.0;
dt_draw_line(cr, left + x_3, top, left + x_3, bottom);
dt_draw_line(cr, left + 2 * x_3, top, left + 2 * x_3, bottom);
dt_draw_line(cr, left, top + y_3, right, top + y_3);
dt_draw_line(cr, left, top + 2 * y_3, right, top + 2 * y_3);
}
static void dt_guides_draw_metering(cairo_t *cr, const float x, const float y, const float w, const float h)
{
const float x_step = w / (X_LINES - 1), y_step = h / (Y_LINES - 1), length_short = MIN(w, h) * 0.02,
length_middle = length_short * 1.5,
length_long = length_middle * 1.5; // these are effectively * 2!
cairo_save(cr);
cairo_translate(cr, x, y);
// along x axis
cairo_save(cr);
cairo_translate(cr, 0, h * 0.5);
for(int i = 0; i < X_LINES; i++)
if(i % 4 != 0)
dt_draw_line(cr, i * x_step, -length_short, i * x_step, length_short); // short lines
else if(i % 12 != 0)
dt_draw_line(cr, i * x_step, -length_middle, i * x_step, length_middle); // medium lines
else if(i != X_LINES / 2)
dt_draw_line(cr, i * x_step, -length_long, i * x_step, length_long); // long lines
else
dt_draw_line(cr, i * x_step, -h * 0.5, i * x_step, h * 0.5); // middle line
cairo_restore(cr);
// along y axis
cairo_save(cr);
cairo_translate(cr, w * 0.5, 0);
for(int i = 0; i < Y_LINES; i++)
if((i - 4) % 4 != 0)
dt_draw_line(cr, -length_short, i * y_step, length_short, i * y_step); // short lines
else if(i == Y_LINES / 2)
dt_draw_line(cr, -w * 0.5, i * y_step, w * 0.5, i * y_step); // middle line
else if((i - 4) % 12 != 0)
dt_draw_line(cr, -length_middle, i * y_step, length_middle, i * y_step); // medium lines
else
dt_draw_line(cr, -length_long, i * y_step, length_long, i * y_step); // long lines
cairo_restore(cr);
// small crosses
const float length_cross = length_short * .5, cross_x_step = w / CROSSES, cross_y_step = h / CROSSES;
for(int x = 1; x < CROSSES; x++)
for(int y = 1; y < CROSSES; y++)
if(x != CROSSES / 2 && y != CROSSES / 2)
{
float _x = x * cross_x_step, _y = y * cross_y_step;
dt_draw_line(cr, _x - length_cross, _y, _x + length_cross, _y);
dt_draw_line(cr, _x, _y - length_cross, _x, _y + length_cross);
}
cairo_restore(cr);
}
static int _draw_line(lua_State *L)
{
cairo_t *cr;
luaA_to(L, dt_lua_cairo_t, &cr, 1);
lua_Number left = luaL_checknumber(L, 2);
lua_Number top = luaL_checknumber(L, 3);
lua_Number right = luaL_checknumber(L, 4);
lua_Number bottom = luaL_checknumber(L, 5);
dt_draw_line(cr, left, top, right, bottom);
return 0;
}
static void dt_guides_draw_diagonal_method(cairo_t *cr, const float x, const float y, const float w, const float h)
{
if(w > h)
{
dt_draw_line(cr, x, y, x + h, y + h);
dt_draw_line(cr, x, y + h, x + h, y);
dt_draw_line(cr, x + w - h, y, x + w, y + h);
dt_draw_line(cr, x + w - h, y + h, x + w, y);
}
else
{
dt_draw_line(cr, x, y, x + w, y + w);
dt_draw_line(cr, x, y + w, x + w, y);
dt_draw_line(cr, x, y + h - w, x + w, y + h);
dt_draw_line(cr, x, y + h, x + w, y + h - w);
}
}
static void dt_guides_draw_perspective(cairo_t *cr, const float x, const float y, const float w, const float h)
{
const float rotation_step = 2.0 / PERSPECTIVE_LINES,
line_length = w * w + h * h; // no need for sqrt or *0.25, this is inside a cairo_clip anyway
cairo_save(cr);
for(int i = 0; i < PERSPECTIVE_LINES; i++)
{
cairo_save(cr);
cairo_rotate(cr, -M_PI * rotation_step * i);
dt_draw_line(cr, 0, 0, line_length, 0);
cairo_restore(cr);
}
cairo_restore(cr);
}
void
dt_guides_draw_golden_mean(cairo_t *cr, dt_QRect_t* R1, dt_QRect_t* R2, dt_QRect_t* R3, dt_QRect_t* R4, dt_QRect_t* R5, dt_QRect_t* R6, dt_QRect_t* R7, gboolean goldenSection, gboolean goldenTriangle, gboolean goldenSpiralSection, gboolean goldenSpiral)
{
// Drawing Golden sections.
if (goldenSection)
{
// horizontal lines:
dt_draw_line(cr, R1->left, R2->top, R2->right, R2->top);
dt_draw_line(cr, R1->left, R1->top + R2->height, R2->right, R1->top + R2->height);
// vertical lines:
dt_draw_line(cr, R1->right, R1->top, R1->right, R1->bottom);
dt_draw_line(cr, R1->left+R2->width, R1->top, R1->left+R2->width, R1->bottom);
}
// Drawing Golden triangle guides.
if (goldenTriangle)
{
dt_draw_line(cr, R1->left, R1->bottom, R2->right, R1->top);
dt_draw_line(cr, R1->left, R1->top, R2->right-R1->width, R1->bottom);
dt_draw_line(cr, R1->left + R1->width, R1->top, R2->right, R1->bottom);
}
// Drawing Golden spiral sections.
if (goldenSpiralSection)
{
dt_draw_line(cr, R1->right, R1->top, R1->right, R1->bottom);
dt_draw_line(cr, R2->left, R2->top, R2->right, R2->top);
dt_draw_line(cr, R3->left, R3->top, R3->left, R3->bottom);
dt_draw_line(cr, R4->left, R4->bottom, R4->right, R4->bottom);
dt_draw_line(cr, R5->right, R5->top, R5->right, R5->bottom);
dt_draw_line(cr, R6->left, R6->top, R6->right, R6->top);
dt_draw_line(cr, R7->left, R7->top, R7->left, R7->bottom);
}
// Drawing Golden Spiral.
if (goldenSpiral)
{
cairo_save(cr);
cairo_new_sub_path(cr);
cairo_scale(cr, R1->width/R1->height, 1);
cairo_arc ( cr, R1->right/R1->width*R1->height, R1->top, R1->height, RADIANS(90), RADIANS(180) );
cairo_restore(cr);
cairo_save(cr);
cairo_new_sub_path(cr);
cairo_scale(cr, R2->width/R2->height, 1);
cairo_arc ( cr, R2->left/R2->width*R2->height, R2->top, R2->height, RADIANS(0), RADIANS(90));
cairo_restore(cr);
cairo_save(cr);
cairo_new_sub_path(cr);
cairo_scale(cr, R3->width/R3->height, 1);
cairo_arc ( cr, R3->left/R3->width*R3->height, R3->bottom, R3->height, RADIANS(270), RADIANS(360));
cairo_restore(cr);
cairo_save(cr);
cairo_new_sub_path(cr);
cairo_scale(cr, 1, R4->height/R4->width);
cairo_arc ( cr, R4->right, R4->bottom/R4->height*R4->width, R4->width, RADIANS(180), RADIANS(270));
cairo_restore(cr);
cairo_save(cr);
cairo_new_sub_path(cr);
cairo_scale(cr, 1, R5->height/R5->width);
cairo_arc ( cr, R5->right, R5->top/R5->height*R5->width, R5->width, RADIANS(90), RADIANS(180));
cairo_restore(cr);
cairo_save(cr);
cairo_new_sub_path(cr);
cairo_scale(cr, 1, R6->height/R6->width);
cairo_arc ( cr, R6->left, R6->top/R6->height*R6->width, R6->width, RADIANS(0), RADIANS(90));
cairo_restore(cr);
cairo_save(cr);
cairo_new_sub_path(cr);
cairo_scale(cr, R7->width/R7->height, 1);
cairo_arc ( cr, R7->left/R7->width*R7->height, R7->bottom, R7->height, RADIANS(270), RADIANS(360));
cairo_restore(cr);
cairo_save(cr);
cairo_new_sub_path(cr);
cairo_scale(cr, (R6->width-R7->width)/R7->height, 1);
cairo_arc ( cr, R7->left/(R6->width-R7->width)*R7->height, R7->bottom, R7->height, RADIANS(210), RADIANS(270));
cairo_restore(cr);
}
}
