/* * Clutter COGL * * A basic GL/GLES Abstraction/Utility Layer * * Authored By Matthew Allum * * Copyright (C) 2007 OpenedHand * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include "cogl.h" #include "cogl-internal.h" #include "cogl-context.h" #include #include #define _COGL_MAX_BEZ_RECURSE_DEPTH 16 /** * SECTION:cogl-primitives * @short_description: Functions that draw various primitive shapes and * allow for construction of more complex paths. * * There are three levels on which drawing with cogl can be used. The * highest level functions construct various simple primitive shapes * to be either filled or stroked. Using a lower-level set of functions * more complex and arbitrary paths can be constructed by concatenating * straight line, bezier curve and arc segments. Additionally there * are utility functions that draw the most common primitives - rectangles * and trapezoids - in a maximaly optimized fashion. * * When constructing arbitrary paths, the current pen location is * initialized using the move_to command. The subsequent path segments * implicitly use the last pen location as their first vertex and move * the pen location to the last vertex they produce at the end. Also * there are special versions of functions that allow specifying the * vertices of the path segments relative to the last pen location * rather then in the absolute coordinates. */ /** * cogl_fast_fill_rectangle: * @x: X coordinate of the top-left corner * @y: Y coordinate of the top-left corner * @width: Width of the rectangle * @height: Height of the rectangle * * Fills a rectangle at the given coordinates with the current * drawing color in a highly optimizied fashion. **/ void cogl_fast_fill_rectangle (gint x, gint y, guint width, guint height) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); cogl_enable (ctx->color_alpha < 255 ? COGL_ENABLE_BLEND : 0); GE( glRecti (x, y, x + width, y + height) ); } /** * cogl_fast_fill_rectanglex: * @x: X coordinate of the top-left corner * @y: Y coordinate of the top-left corner * @width: Width of the rectangle * @height: Height of the rectangle * * A fixed-point version of cogl_fast_fill_rectangle. **/ void cogl_fast_fill_rectanglex (ClutterFixed x, ClutterFixed y, ClutterFixed width, ClutterFixed height) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); cogl_enable (ctx->color_alpha < 255 ? COGL_ENABLE_BLEND : 0); GE( glRectf (CLUTTER_FIXED_TO_FLOAT (x), CLUTTER_FIXED_TO_FLOAT (y), CLUTTER_FIXED_TO_FLOAT (x + width), CLUTTER_FIXED_TO_FLOAT (y + height)) ); } /** * cogl_fast_fill_trapezoid: * @y1: Y coordinate of the top two vertices. * @x11: X coordinate of the top-left vertex. * @x21: X coordinate of the top-right vertex. * @y2: Y coordinate of the bottom two vertices. * @x12: X coordinate of the bottom-left vertex. * @x22: X coordinate of the bottom-right vertex. * * Fills a trapezoid at the given coordinates with the current * drawing color in a highly optimized fashion. **/ void cogl_fast_fill_trapezoid (gint y1, gint x11, gint x21, gint y2, gint x12, gint x22) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); cogl_enable (ctx->color_alpha < 255 ? COGL_ENABLE_BLEND : 0); GE( glBegin (GL_QUADS) ); GE( glVertex2i (x11, y1) ); GE( glVertex2i (x21, y1) ); GE( glVertex2i (x22, y2) ); GE( glVertex2i (x12, y2) ); GE( glEnd () ); } /** * cogl_fast_fill_trapezoidx: * @y1: Y coordinate of the top two vertices. * @x11: X coordinate of the top-left vertex. * @x21: X coordinate of the top-right vertex. * @y2: Y coordinate of the bottom two vertices. * @x12: X coordinate of the bottom-left vertex. * @x22: X coordinate of the bottom-right vertex. * * A fixed-point version of cogl_fast_fill_trapezoid. **/ void cogl_fast_fill_trapezoidx (ClutterFixed y1, ClutterFixed x11, ClutterFixed x21, ClutterFixed y2, ClutterFixed x12, ClutterFixed x22) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); cogl_enable (ctx->color_alpha < 255 ? COGL_ENABLE_BLEND : 0); GE( glBegin (GL_QUADS) ); GE( glVertex2f (CLUTTER_FIXED_TO_FLOAT (x11), CLUTTER_FIXED_TO_FLOAT (y1)) ); GE( glVertex2f (CLUTTER_FIXED_TO_FLOAT (x21), CLUTTER_FIXED_TO_FLOAT (y1)) ); GE( glVertex2f (CLUTTER_FIXED_TO_FLOAT (x22), CLUTTER_FIXED_TO_FLOAT (y2)) ); GE( glVertex2f (CLUTTER_FIXED_TO_FLOAT (x12), CLUTTER_FIXED_TO_FLOAT (y2)) ); GE( glEnd () ); } static void _cogl_path_clear_nodes () { _COGL_GET_CONTEXT (ctx, NO_RETVAL); if (ctx->path_nodes) g_free(ctx->path_nodes); ctx->path_nodes = (CoglFloatVec2*) g_malloc (2 * sizeof(CoglFloatVec2)); ctx->path_nodes_size = 0; ctx->path_nodes_cap = 2; } static void _cogl_path_add_node (ClutterFixed x, ClutterFixed y) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); CoglFloatVec2 *new_nodes = NULL; if (ctx->path_nodes_size == ctx->path_nodes_cap) { new_nodes = g_realloc (ctx->path_nodes, 2 * ctx->path_nodes_cap * sizeof (CoglFloatVec2)); if (new_nodes == NULL) return; ctx->path_nodes = new_nodes; ctx->path_nodes_cap *= 2; } ctx->path_nodes [ctx->path_nodes_size] .x = CLUTTER_FIXED_TO_FLOAT (x); ctx->path_nodes [ctx->path_nodes_size] .y = CLUTTER_FIXED_TO_FLOAT (y); ctx->path_nodes_size++; if (ctx->path_nodes_size == 1) { ctx->path_nodes_min.x = ctx->path_nodes_max.x = x; ctx->path_nodes_min.y = ctx->path_nodes_max.y = y; } else { if (x < ctx->path_nodes_min.x) ctx->path_nodes_min.x = x; if (x > ctx->path_nodes_max.x) ctx->path_nodes_max.x = x; if (y < ctx->path_nodes_min.y) ctx->path_nodes_min.y = y; if (y > ctx->path_nodes_max.y) ctx->path_nodes_max.y = y; } } static void _cogl_path_stroke_nodes () { _COGL_GET_CONTEXT (ctx, NO_RETVAL); cogl_enable (COGL_ENABLE_VERTEX_ARRAY | (ctx->color_alpha < 255 ? COGL_ENABLE_BLEND : 0)); GE( glVertexPointer (2, GL_FLOAT, 0, ctx->path_nodes) ); GE( glDrawArrays (GL_LINE_STRIP, 0, ctx->path_nodes_size) ); } static void _cogl_path_fill_nodes () { _COGL_GET_CONTEXT (ctx, NO_RETVAL); guint bounds_x; guint bounds_y; guint bounds_w; guint bounds_h; GE( glClear (GL_STENCIL_BUFFER_BIT) ); GE( glEnable (GL_STENCIL_TEST) ); GE( glStencilFunc (GL_ALWAYS, 0x0, 0x0) ); GE( glStencilOp (GL_INVERT, GL_INVERT, GL_INVERT) ); GE( glColorMask (GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE) ); cogl_enable (COGL_ENABLE_VERTEX_ARRAY | (ctx->color_alpha < 255 ? COGL_ENABLE_BLEND : 0)); GE( glVertexPointer (2, GL_FLOAT, 0, ctx->path_nodes) ); GE( glDrawArrays (GL_TRIANGLE_FAN, 0, ctx->path_nodes_size) ); GE( glStencilFunc (GL_EQUAL, 0x1, 0x1) ); GE( glStencilOp (GL_ZERO, GL_ZERO, GL_ZERO) ); GE( glColorMask (GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE) ); bounds_x = CLUTTER_FIXED_FLOOR (ctx->path_nodes_min.x); bounds_y = CLUTTER_FIXED_FLOOR (ctx->path_nodes_min.y); bounds_w = CLUTTER_FIXED_CEIL (ctx->path_nodes_max.x - ctx->path_nodes_min.x); bounds_h = CLUTTER_FIXED_CEIL (ctx->path_nodes_max.y - ctx->path_nodes_min.y); cogl_fast_fill_rectangle (bounds_x, bounds_y, bounds_w, bounds_h); GE( glDisable (GL_STENCIL_TEST) ); } /** * cogl_fill: * * Fills the constructed shape using the current drawing color. **/ void cogl_fill () { _COGL_GET_CONTEXT (ctx, NO_RETVAL); if (ctx->path_nodes_size == 0) return; _cogl_path_fill_nodes(); } /** * cogl_stroke: * * Strokes the constructed shape using the current drawing color * and a width of 1 pixel (regardless of the current transformation * matrix). **/ void cogl_stroke () { _COGL_GET_CONTEXT (ctx, NO_RETVAL); if (ctx->path_nodes_size == 0) return; _cogl_path_stroke_nodes(); } /** * cogl_path_move_to: * @x: X coordinate of the pen location to move to. * @y: Y coordinate of the pen location to move to. * * Clears the previously constructed shape and begins a new path * contour by moving the pen to the given coordinates. **/ void cogl_path_move_to (ClutterFixed x, ClutterFixed y) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); /* FIXME: handle multiple contours maybe? */ _cogl_path_clear_nodes (); _cogl_path_add_node (x, y); ctx->path_start.x = x; ctx->path_start.y = y; ctx->path_pen = ctx->path_start; } /** * cogl_path_move_to_rel: * @x: X offset from the current pen location to move the pen to. * @y: Y offset from the current pen location to move the pen to. * * Clears the previously constructed shape and begins a new path * contour by moving the pen to the given coordinates relative * to the current pen location. **/ void cogl_path_move_to_rel (ClutterFixed x, ClutterFixed y) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); cogl_path_move_to (ctx->path_pen.x + x, ctx->path_pen.y + y); } /** * cogl_path_line_to: * @x: X coordinate of the end line vertex * @y: Y coordinate of the end line vertex * * Adds a straight line segment to the current path that ends at the * given coordinates. **/ void cogl_path_line_to (ClutterFixed x, ClutterFixed y) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); _cogl_path_add_node (x, y); ctx->path_pen.x = x; ctx->path_pen.y = y; } /** * cogl_path_line_to: * @x: X offset from the current pen location of the end line vertex * @y: Y offset from the current pen location of the end line vertex * * Adds a straight line segment to the current path that ends at the * given coordinates relative to the current pen location. **/ void cogl_path_line_to_rel (ClutterFixed x, ClutterFixed y) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); cogl_path_line_to (ctx->path_pen.x + x, ctx->path_pen.y + y); } /** * cogl_path_h_line_to: * @x: X coordinate of the end line vertex * * Adds a straight horizontal line segment to the current path that * ends at the given X coordinate and current pen Y coordinate. **/ void cogl_path_h_line_to (ClutterFixed x) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); cogl_path_line_to (x, ctx->path_pen.y); } /** * cogl_path_v_line_to: * @y: Y coordinate of the end line vertex * * Adds a stright vertical line segment to the current path that ends * at the current pen X coordinate and the given Y coordinate. **/ void cogl_path_v_line_to (ClutterFixed y) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); cogl_path_line_to (ctx->path_pen.x, y); } /** * cogl_path_h_line_to_rel: * @x: X offset from the current pen location of the end line vertex * * Adds a straight horizontal line segment to the current path that * ends at the given X coordinate relative to the current pen location * and current pen Y coordinate. **/ void cogl_path_h_line_to_rel (ClutterFixed x) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); cogl_path_line_to (ctx->path_pen.x + x, ctx->path_pen.y); } /** * cogl_path_v_line_to_rel: * @y: Y offset from the current pen location of the end line vertex * * Adds a stright vertical line segment to the current path that ends * at the current pen X coordinate and the given Y coordinate relative * to the current pen location. **/ void cogl_path_v_line_to_rel (ClutterFixed y) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); cogl_path_line_to (ctx->path_pen.x, ctx->path_pen.y + y); } /** * cogl_path_close: * * Closes the path being constructed by adding a straight line segment * to it that ends at the first vertex of the path. **/ void cogl_path_close () { _COGL_GET_CONTEXT (ctx, NO_RETVAL); _cogl_path_add_node (ctx->path_start.x, ctx->path_start.y); ctx->path_pen = ctx->path_start; } /** * cogl_line: * @x1: X coordinate of the start line vertex * @y1: Y coordinate of the start line vertex * @x2: X coordinate of the end line vertex * @y2: Y coordinate of the end line vertex * * Clears the previously constructed shape and constructs a straight * line shape start and ending at the given coordinates. **/ void cogl_line (ClutterFixed x1, ClutterFixed y1, ClutterFixed x2, ClutterFixed y2) { cogl_path_move_to (x1, y1); cogl_path_line_to (x2, y2); } /** * cogl_polyline: * @coords: A pointer to the first element of an array of fixed-point * values that specify the vertex coordinates. * @num_points: The total number of vertices. * * Clears the previously constructed shape and constructs a series of straight * line segments, starting from the first given vertex coordinate. Each * subsequent segment stars where the previous one ended and ends at the next * given vertex coordinate. * * The coords array must contain 2 * num_points values. The first value * represents the X coordinate of the first vertex, the second value * represents the Y coordinate of the first vertex, continuing in the same * fashion for the rest of the vertices. (num_points - 1) segments will * be constructed. **/ void cogl_polyline (ClutterFixed *coords, gint num_points) { gint c = 0; cogl_path_move_to (coords[0], coords[1]); for (c = 1; c < num_points; ++c) cogl_path_line_to (coords[2*c], coords[2*c+1]); } /** * cogl_polygon: * @coords: A pointer to the first element of an array of fixed-point * values that specify the vertex coordinates. * @num_points: The total number of vertices. * * Clears the previously constructed shape and constructs a polygonal * shape of the given number of vertices. * * The coords array must contain 2 * num_points values. The first value * represents the X coordinate of the first vertex, the second value * represents the Y coordinate of the first vertex, continuing in the same * fashion for the rest of the vertices. **/ void cogl_polygon (ClutterFixed *coords, gint num_points) { cogl_polyline (coords, num_points); cogl_path_close (); } /** * cogl_rectangle: * @x: X coordinate of the top-left corner. * @y: Y coordinate of the top-left corner. * @width: Rectangle width. * @height: Rectangle height. * * Clears the previously constructed shape and constructs a rectangular * shape at the given coordinates. **/ void cogl_rectangle (ClutterFixed x, ClutterFixed y, ClutterFixed width, ClutterFixed height) { cogl_path_move_to (x, y); cogl_path_line_to (x + width, y); cogl_path_line_to (x + width, y + height); cogl_path_line_to (x, y + height); cogl_path_close (); } static void _cogl_arc (ClutterFixed center_x, ClutterFixed center_y, ClutterFixed radius_x, ClutterFixed radius_y, ClutterAngle angle_1, ClutterAngle angle_2, ClutterAngle angle_step, guint move_first) { ClutterAngle a = 0x0; ClutterAngle temp = 0x0; ClutterFixed cosa = 0x0; ClutterFixed sina = 0x0; ClutterFixed px = 0x0; ClutterFixed py = 0x0; /* Fix invalid angles */ if (angle_1 == angle_2 || angle_step == 0x0) return; if (angle_step < 0x0) angle_step = -angle_step; if (angle_2 < angle_1) { temp = angle_1; angle_1 = angle_2; angle_2 = temp; } /* Walk the arc by given step */ for (a = angle_1; a < angle_2; a += angle_step) { cosa = clutter_cosi (a); sina = clutter_sini (a); px = center_x + CFX_MUL (cosa, radius_x); py = center_y + CFX_MUL (sina, radius_y); if (a == angle_1 && move_first) cogl_path_move_to (px, py); else cogl_path_line_to (px, py); } } /** * cogl_path_arc: * @center_x: X coordinate of the elliptical arc center * @center_y: Y coordinate of the elliptical arc center * @radius_x: X radius of the elliptical arc * @radius_y: Y radious of the elliptical arc * @angle_1: Angle in the unit-circle at which the arc begin * @angle_2: Angle in the unit-circle at which the arc ends * @angle_step: Angle increment resolution for subdivision * * Adds an elliptical arc segment to the current path. A straight line * segment will link the current pen location with the first vertex * of the arc. **/ void cogl_path_arc (ClutterFixed center_x, ClutterFixed center_y, ClutterFixed radius_x, ClutterFixed radius_y, ClutterAngle angle_1, ClutterAngle angle_2, ClutterAngle angle_step) { _cogl_arc (center_x, center_y, radius_x, radius_y, angle_1, angle_2, angle_step, 0 /* no move */); } /** * cogl_path_arc_rel: * @center_x: X offset from the current pen location of the elliptical * arc center * @center_y: Y offset from the current pen location of the elliptical * arc center * @radius_x: X radius of the elliptical arc * @radius_y: Y radious of the elliptical arc * @angle_1: Angle in the unit-circle at which the arc begin * @angle_2: Angle in the unit-circle at which the arc ends * @angle_step: Angle increment resolution for subdivision * * Adds an elliptical arc segment to the current path. A straight line * segment will link the current pen location with the first vertex * of the arc. **/ void cogl_path_arc_rel (ClutterFixed center_x, ClutterFixed center_y, ClutterFixed radius_x, ClutterFixed radius_y, ClutterAngle angle_1, ClutterAngle angle_2, ClutterAngle angle_step) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); _cogl_arc (ctx->path_pen.x + center_x, ctx->path_pen.y + center_y, radius_x, radius_y, angle_1, angle_2, angle_step, 0 /* no move */); } /** * cogl_arc: * @center_x: X coordinate of the elliptical arc center * @center_y: Y coordinate of the elliptical arc center * @radius_x: X radius of the elliptical arc * @radius_y: Y radious of the elliptical arc * @angle_1: Angle in the unit-circle at which the arc begin * @angle_2: Angle in the unit-circle at which the arc ends * @angle_step: Angle increment resolution for subdivision * * Clears the previously constructed shape and constructs and elliptical arc * shape. **/ void cogl_arc (ClutterFixed center_x, ClutterFixed center_y, ClutterFixed radius_x, ClutterFixed radius_y, ClutterAngle angle_1, ClutterAngle angle_2, ClutterAngle angle_step) { _cogl_arc (center_x, center_y, radius_x, radius_y, angle_1, angle_2, angle_step, 1 /* move first */); } /** * cogl_ellipse: * @center_x: X coordinate of the ellipse center * @center_y: Y coordinate of the ellipse center * @radius_x: X radius of the ellipse * @radius_y: Y radius of the ellipse * @angle_step: Angle increment resolution for subdivision * * Clears the previously constructed shape and constructs an ellipse * shape. **/ void cogl_ellipse (ClutterFixed center_x, ClutterFixed center_y, ClutterFixed radius_x, ClutterFixed radius_y, ClutterAngle angle_step) { /* FIXME: if shows to be slow might be optimized * by mirroring just a quarter of it */ _cogl_arc (center_x, center_y, radius_x, radius_y, 0, CLUTTER_ANGLE_FROM_DEG(360), angle_step, 1 /* move first */); cogl_path_close(); } /** * cogl_round_rectangle: * @x: X coordinate of the top-left corner * @y: Y coordinate of the top-left corner * @width: Width of the rectangle * @height: Height of the rectangle * @radius: Radius of the corner arcs. * @arc_step: Angle increment resolution for subdivision of * the corner arcs. * * Clears the previously constructed shape and constructs a rectangular * shape with rounded corners. **/ void cogl_round_rectangle (ClutterFixed x, ClutterFixed y, ClutterFixed width, ClutterFixed height, ClutterFixed radius, ClutterAngle arc_step) { ClutterFixed inner_width = width - (radius << 1); ClutterFixed inner_height = height - (radius << 1); cogl_path_move_to (x, y + radius); cogl_path_arc_rel (radius, 0, radius, radius, CLUTTER_ANGLE_FROM_DEG (180), CLUTTER_ANGLE_FROM_DEG (270), arc_step); cogl_path_h_line_to_rel (inner_width); cogl_path_arc_rel (0, radius, radius, radius, CLUTTER_ANGLE_FROM_DEG (-90), CLUTTER_ANGLE_FROM_DEG (0), arc_step); cogl_path_v_line_to_rel (inner_height); cogl_path_arc_rel (-radius, 0, radius, radius, CLUTTER_ANGLE_FROM_DEG (0), CLUTTER_ANGLE_FROM_DEG (90), arc_step); cogl_path_h_line_to_rel (-inner_width); cogl_path_arc_rel (0, -radius, radius, radius, CLUTTER_ANGLE_FROM_DEG (90), CLUTTER_ANGLE_FROM_DEG (180), arc_step); cogl_path_close (); } static void _cogl_path_bezier2_sub (CoglBezQuad *quad) { CoglBezQuad quads[_COGL_MAX_BEZ_RECURSE_DEPTH]; CoglBezQuad *qleft; CoglBezQuad *qright; CoglBezQuad *q; CoglFixedVec2 mid; CoglFixedVec2 dif; CoglFixedVec2 c1; CoglFixedVec2 c2; CoglFixedVec2 c3; gint qindex; /* Put first curve on stack */ quads[0] = *quad; qindex = 0; /* While stack is not empty */ while (qindex >= 0) { q = &quads[qindex]; /* Calculate distance of control point from its * counterpart on the line between end points */ mid.x = ((q->p1.x + q->p3.x) >> 1); mid.y = ((q->p1.y + q->p3.y) >> 1); dif.x = (q->p2.x - mid.x); dif.y = (q->p2.y - mid.y); if (dif.x < 0) dif.x = -dif.x; if (dif.y < 0) dif.y = -dif.y; /* Cancel if the curve is flat enough */ if (dif.x + dif.y <= CFX_ONE || qindex == _COGL_MAX_BEZ_RECURSE_DEPTH - 1) { /* Add subdivision point (skip last) */ if (qindex == 0) return; _cogl_path_add_node (q->p3.x, q->p3.y); --qindex; continue; } /* Left recursion goes on top of stack! */ qright = q; qleft = &quads[++qindex]; /* Subdivide into 2 sub-curves */ c1.x = ((q->p1.x + q->p2.x) >> 1); c1.y = ((q->p1.y + q->p2.y) >> 1); c3.x = ((q->p2.x + q->p3.x) >> 1); c3.y = ((q->p2.y + q->p3.y) >> 1); c2.x = ((c1.x + c3.x) >> 1); c2.y = ((c1.y + c3.y) >> 1); /* Add left recursion onto stack */ qleft->p1 = q->p1; qleft->p2 = c1; qleft->p3 = c2; /* Add right recursion onto stack */ qright->p1 = c2; qright->p2 = c3; qright->p3 = q->p3; } } static void _cogl_path_bezier3_sub (CoglBezCubic *cubic) { CoglBezCubic cubics[_COGL_MAX_BEZ_RECURSE_DEPTH]; CoglBezCubic *cleft; CoglBezCubic *cright; CoglBezCubic *c; CoglFixedVec2 dif1; CoglFixedVec2 dif2; CoglFixedVec2 mm; CoglFixedVec2 c1; CoglFixedVec2 c2; CoglFixedVec2 c3; CoglFixedVec2 c4; CoglFixedVec2 c5; gint cindex; /* Put first curve on stack */ cubics[0] = *cubic; cindex = 0; while (cindex >= 0) { c = &cubics[cindex]; #define CFX_MUL2(x) ((x) << 1) #define CFX_MUL3(x) (((x) << 1) + (x)) #define CFX_SQ(x) CFX_MUL (x, x) /* Calculate distance of control points from their * counterparts on the line between end points */ dif1.x = CFX_MUL3 (c->p2.x) - CFX_MUL2 (c->p1.x) - c->p4.x; dif1.y = CFX_MUL3 (c->p2.y) - CFX_MUL2 (c->p1.y) - c->p4.y; dif2.x = CFX_MUL3 (c->p3.x) - CFX_MUL2 (c->p4.x) - c->p1.x; dif2.y = CFX_MUL3 (c->p3.y) - CFX_MUL2 (c->p4.y) - c->p1.y; if (dif1.x < 0) dif1.x = -dif1.x; if (dif1.y < 0) dif1.y = -dif1.y; if (dif2.x < 0) dif2.x = -dif2.x; if (dif2.y < 0) dif2.y = -dif2.y; #undef CFX_MUL2 #undef CFX_MUL3 #undef CFX_SQ /* Pick the greatest of two distances */ if (dif1.x < dif2.x) dif1.x = dif2.x; if (dif1.y < dif2.y) dif1.y = dif2.y; /* Cancel if the curve is flat enough */ if (dif1.x + dif1.y <= CFX_ONE || cindex == _COGL_MAX_BEZ_RECURSE_DEPTH-1) { /* Add subdivision point (skip last) */ if (cindex == 0) return; _cogl_path_add_node (c->p4.x, c->p4.y); --cindex; continue; } /* Left recursion goes on top of stack! */ cright = c; cleft = &cubics[++cindex]; /* Subdivide into 2 sub-curves */ c1.x = ((c->p1.x + c->p2.x) >> 1); c1.y = ((c->p1.y + c->p2.y) >> 1); mm.x = ((c->p2.x + c->p3.x) >> 1); mm.y = ((c->p2.y + c->p3.y) >> 1); c5.x = ((c->p3.x + c->p4.x) >> 1); c5.y = ((c->p3.y + c->p4.y) >> 1); c2.x = ((c1.x + mm.x) >> 1); c2.y = ((c1.y + mm.y) >> 1); c4.x = ((mm.x + c5.x) >> 1); c4.y = ((mm.y + c5.y) >> 1); c3.x = ((c2.x + c4.x) >> 1); c3.y = ((c2.y + c4.y) >> 1); /* Add left recursion to stack */ cleft->p1 = c->p1; cleft->p2 = c1; cleft->p3 = c2; cleft->p4 = c3; /* Add right recursion to stack */ cright->p1 = c3; cright->p2 = c4; cright->p3 = c5; cright->p4 = c->p4; } } /** * cogl_path_bezier2_to: * @x1: X coordinate of the second bezier control point * @y1: Y coordinate of the second bezier control point * @x2: X coordinate of the third bezier control point * @y2: Y coordinate of the third bezier control point * * Adds a quadratic bezier curve segment to the current path with the given * second and third control points and using current pen location as the * first control point. **/ void cogl_path_bezier2_to (ClutterFixed x1, ClutterFixed y1, ClutterFixed x2, ClutterFixed y2) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); CoglBezQuad quad; /* Prepare quadratic curve */ quad.p1 = ctx->path_pen; quad.p2.x = x1; quad.p2.y = y1; quad.p3.x = x2; quad.p3.y = y2; /* Run subdivision */ _cogl_path_bezier2_sub (&quad); /* Add last point */ _cogl_path_add_node (quad.p3.x, quad.p3.y); ctx->path_pen = quad.p3; } /** * cogl_path_bezier3_to: * @x1: X coordinate of the second bezier control point * @y1: Y coordinate of the second bezier control point * @x2: X coordinate of the third bezier control point * @y2: Y coordinate of the third bezier control point * @x3: X coordinate of the fourth bezier control point * @y3: Y coordinate of the fourth bezier control point * * Adds a cubic bezier curve segment to the current path with the given * second, third and fourth control points and using current pen location * as the first control point. **/ void cogl_path_bezier3_to (ClutterFixed x1, ClutterFixed y1, ClutterFixed x2, ClutterFixed y2, ClutterFixed x3, ClutterFixed y3) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); CoglBezCubic cubic; /* Prepare cubic curve */ cubic.p1 = ctx->path_pen; cubic.p2.x = x1; cubic.p2.y = y1; cubic.p3.x = x2; cubic.p3.y = y2; cubic.p4.x = x3; cubic.p4.y = y3; /* Run subdivision */ _cogl_path_bezier3_sub (&cubic); /* Add last point */ _cogl_path_add_node (cubic.p4.x, cubic.p4.y); ctx->path_pen = cubic.p4; } /** * cogl_path_bezier2_to_rel: * @x1: X coordinate of the second bezier control point * @y1: Y coordinate of the second bezier control point * @x2: X coordinate of the third bezier control point * @y2: Y coordinate of the third bezier control point * * Adds a quadratic bezier curve segment to the current path with the given * second and third control points and using current pen location as the * first control point. The given coordinates are relative to the current * pen location. **/ void cogl_path_bezier2_to_rel (ClutterFixed x1, ClutterFixed y1, ClutterFixed x2, ClutterFixed y2) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); cogl_path_bezier2_to (ctx->path_pen.x + x1, ctx->path_pen.y + y2, ctx->path_pen.x + x2, ctx->path_pen.y + y2); } /** * cogl_path_bezier3_to_rel: * @x1: X coordinate of the second bezier control point * @y1: Y coordinate of the second bezier control point * @x2: X coordinate of the third bezier control point * @y2: Y coordinate of the third bezier control point * @x3: X coordinate of the fourth bezier control point * @y3: Y coordinate of the fourth bezier control point * * Adds a cubic bezier curve segment to the current path with the given * second, third and fourth control points and using current pen location * as the first control point. The given coordinates are relative to the * current pen location. **/ void cogl_path_bezier3_to_rel (ClutterFixed x1, ClutterFixed y1, ClutterFixed x2, ClutterFixed y2, ClutterFixed x3, ClutterFixed y3) { _COGL_GET_CONTEXT (ctx, NO_RETVAL); cogl_path_bezier3_to (ctx->path_pen.x + x1, ctx->path_pen.y + y2, ctx->path_pen.x + x2, ctx->path_pen.y + y2, ctx->path_pen.x + x3, ctx->path_pen.y + y3); }