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Diffstat (limited to 'test/radial-gradient.c')
| -rw-r--r-- | test/radial-gradient.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/test/radial-gradient.c b/test/radial-gradient.c new file mode 100644 index 000000000..026876b1b --- /dev/null +++ b/test/radial-gradient.c @@ -0,0 +1,256 @@ +/* + * Copyright © 2005, 2007 Red Hat, Inc. + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + * + * Author: Carl D. Worth <cworth@cworth.org> + */ + +#include "cairo-test.h" + +#define NUM_GRADIENTS 7 +#define NUM_EXTEND 4 +#define SIZE 120 +#define WIDTH (SIZE * NUM_GRADIENTS) +#define HEIGHT (SIZE * NUM_EXTEND) + +typedef void (*composite_t)(cairo_t *cr, cairo_pattern_t *pattern); +typedef void (*add_stops_t)(cairo_pattern_t *pattern); + +/* + * We want to test all the possible relative positions of the start + * and end circle: + * + * - The start circle can be smaller/equal/bigger than the end + * circle. A radial gradient can be classified in one of these + * three cases depending on the sign of dr. + * + * - The smaller circle can be completely inside/internally + * tangent/outside (at least in part) of the bigger circle. This + * classification is the same as the one which can be computed by + * examining the sign of a = (dx^2 + dy^2 - dr^2). + * + * - If the two circles have the same size, neither can be inside or + * internally tangent + * + * This test draws radial gradients whose circles always have the same + * centers (0, 0) and (1, 0), but with different radiuses. From left + * to right: + * + * - Small start circle completely inside the end circle + * 0.25 -> 1.75; dr = 1.5 > 0; a = 1 - 1.50^2 < 0 + * + * - Small start circle internally tangent to the end circle + * 0.50 -> 1.50; dr = 1.0 > 0; a = 1 - 1.00^2 = 0 + * + * - Small start circle outside of the end circle + * 0.50 -> 1.00; dr = 0.5 > 0; a = 1 - 0.50^2 > 0 + * + * - Start circle with the same size as the end circle + * 1.00 -> 1.00; dr = 0.0 = 0; a = 1 - 0.00^2 > 0 + * + * - Small end circle outside of the start circle + * 1.00 -> 0.50; dr = -0.5 > 0; a = 1 - 0.50^2 > 0 + * + * - Small end circle internally tangent to the start circle + * 1.50 -> 0.50; dr = -1.0 > 0; a = 1 - 1.00^2 = 0 + * + * - Small end circle completely inside the start circle + * 1.75 -> 0.25; dr = -1.5 > 0; a = 1 - 1.50^2 < 0 + * + */ + +static const double radiuses[NUM_GRADIENTS] = { + 0.25, + 0.50, + 0.50, + 1.00, + 1.00, + 1.50, + 1.75 +}; + +static cairo_pattern_t * +create_pattern (int index) +{ + double x0, x1, radius0, radius1, left, right, center; + + x0 = 0; + x1 = 1; + radius0 = radiuses[index]; + radius1 = radiuses[NUM_GRADIENTS - index - 1]; + + /* center the gradient */ + left = MIN (x0 - radius0, x1 - radius1); + right = MAX (x0 + radius0, x1 + radius1); + center = (left + right) * 0.5; + x0 -= center; + x1 -= center; + + /* scale to make it fit within a 1x1 rect centered in (0,0) */ + x0 *= 0.25; + x1 *= 0.25; + radius0 *= 0.25; + radius1 *= 0.25; + + return cairo_pattern_create_radial (x0, 0, radius0, x1, 0, radius1); +} + +static void +pattern_add_stops (cairo_pattern_t *pattern) +{ + cairo_pattern_add_color_stop_rgba (pattern, 0.0, 1, 0, 0, 0.75); + cairo_pattern_add_color_stop_rgba (pattern, sqrt (0.5), 0, 1, 0, 0); + cairo_pattern_add_color_stop_rgba (pattern, 1.0, 0, 0, 1, 1); +} + +static void +pattern_add_single_stop (cairo_pattern_t *pattern) +{ + cairo_pattern_add_color_stop_rgba (pattern, 0.25, 1, 0, 0, 1); +} + + +static cairo_test_status_t +draw (cairo_t *cr, add_stops_t add_stops, composite_t composite) +{ + int i, j; + cairo_extend_t extend[NUM_EXTEND] = { + CAIRO_EXTEND_NONE, + CAIRO_EXTEND_REPEAT, + CAIRO_EXTEND_REFLECT, + CAIRO_EXTEND_PAD + }; + + cairo_scale (cr, SIZE, SIZE); + cairo_translate (cr, 0.5, 0.5); + + for (j = 0; j < NUM_EXTEND; j++) { + cairo_save (cr); + for (i = 0; i < NUM_GRADIENTS; i++) { + cairo_pattern_t *pattern; + + pattern = create_pattern (i); + add_stops (pattern); + cairo_pattern_set_extend (pattern, extend[j]); + + cairo_save (cr); + cairo_rectangle (cr, -0.5, -0.5, 1, 1); + cairo_clip (cr); + composite (cr, pattern); + cairo_restore (cr); + cairo_pattern_destroy (pattern); + + cairo_translate (cr, 1, 0); + } + cairo_restore (cr); + cairo_translate (cr, 0, 1); + } + + return CAIRO_TEST_SUCCESS; +} + + +static void +composite_simple (cairo_t *cr, cairo_pattern_t *pattern) +{ + cairo_set_source (cr, pattern); + cairo_paint (cr); +} + +static void +composite_mask (cairo_t *cr, cairo_pattern_t *pattern) +{ + cairo_set_source_rgb (cr, 1, 0, 1); + cairo_mask (cr, pattern); +} + + +static cairo_test_status_t +draw_simple (cairo_t *cr, int width, int height) +{ + cairo_test_paint_checkered (cr); + return draw (cr, pattern_add_stops, composite_simple); +} + +static cairo_test_status_t +draw_mask (cairo_t *cr, int width, int height) +{ + cairo_test_paint_checkered (cr); + return draw (cr, pattern_add_stops, composite_mask); +} + +static cairo_test_status_t +draw_source (cairo_t *cr, int width, int height) +{ + cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE); + return draw (cr, pattern_add_stops, composite_simple); +} + + +static cairo_test_status_t +draw_mask_source (cairo_t *cr, int width, int height) +{ + cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE); + return draw (cr, pattern_add_stops, composite_mask); +} + +static cairo_test_status_t +draw_one_stop (cairo_t *cr, int width, int height) +{ + cairo_test_paint_checkered (cr); + return draw (cr, pattern_add_single_stop, composite_simple); +} + +CAIRO_TEST (radial_gradient, + "Simple test of radial gradients", + "gradient", /* keywords */ + NULL, /* requirements */ + WIDTH, HEIGHT, + NULL, draw_simple) + +CAIRO_TEST (radial_gradient_mask, + "Simple test of radial gradients using a MASK", + "gradient,mask", /* keywords */ + NULL, /* requirements */ + WIDTH, HEIGHT, + NULL, draw_mask) + +CAIRO_TEST (radial_gradient_source, + "Simple test of radial gradients using the SOURCE operator", + "gradient,source", /* keywords */ + NULL, /* requirements */ + WIDTH, HEIGHT, + NULL, draw_source) + +CAIRO_TEST (radial_gradient_mask_source, + "Simple test of radial gradients using a MASK with a SOURCE operator", + "gradient,mask,source", /* keywords */ + NULL, /* requirements */ + WIDTH, HEIGHT, + NULL, draw_mask_source) + +CAIRO_TEST (radial_gradient_one_stop, + "Tests radial gradients with a single stop", + "gradient,radial", /* keywords */ + NULL, /* requirements */ + WIDTH, HEIGHT, + NULL, draw_one_stop) |