75 lines
2.3 KiB
Plaintext
75 lines
2.3 KiB
Plaintext
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/*
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* st-scroll-view-fade.glsl: Edge fade effect for StScrollView
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*
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* Copyright 2010 Intel Corporation.
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* Copyright 2011 Adel Gadllah
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU Lesser General Public License,
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* version 2.1, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT ANY
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* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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* FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
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* more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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uniform sampler2D tex;
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uniform float height;
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uniform float width;
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uniform float offset_bottom;
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uniform float offset_top;
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uniform float offset_right;
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uniform float offset_left;
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/*
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* Used to pass the fade area to the shader
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*
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* [0][0] = x1
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* [0][1] = y1
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* [1][0] = x2
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* [1][1] = y2
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*
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*/
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uniform mat2 fade_area;
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void main ()
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{
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vec4 color = cogl_color_in * texture2D (tex, vec2 (cogl_tex_coord_in[0].xy));
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float y = height * cogl_tex_coord_in[0].y;
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float x = width * cogl_tex_coord_in[0].x;
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float ratio = 1.0;
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float fade_bottom_start = fade_area[1][1] - offset_bottom;
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float fade_right_start = fade_area[1][0] - offset_right;
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float ratio_top = y / offset_top;
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float ratio_bottom = (fade_area[1][1] - y)/(fade_area[1][1] - fade_bottom_start);
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float ratio_left = x / offset_left;
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float ratio_right = (fade_area[1][0] - x)/(fade_area[1][0] - fade_right_start);
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bool in_scroll_area = fade_area[0][0] <= x && fade_area[1][0] >= x;
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bool fade_top = y < offset_top && in_scroll_area && (y >= fade_area[0][1]);
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bool fade_bottom = y > fade_bottom_start && in_scroll_area && (y <= fade_area[1][1]);
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bool fade_left = x < offset_left && in_scroll_area && (x >= fade_area[0][0]);
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bool fade_right = x > fade_right_start && in_scroll_area && (x <= fade_area[1][0]);
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if (fade_top) {
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ratio *= ratio_top;
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}
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if (fade_bottom) {
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ratio *= ratio_bottom;
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}
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if (fade_left) {
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ratio *= ratio_left;
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}
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if (fade_right) {
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ratio *= ratio_right;
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}
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cogl_color_out = color * ratio;
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}
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