mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-11-03 16:09:39 +00:00
8a92c66440
These two shader will calculate the vector length and use it as denominator. But length could be zero which will cause undefine behaviour. Add protection for this condition https://bugzilla.gnome.org/show_bug.cgi?id=767635
548 lines
17 KiB
C
548 lines
17 KiB
C
/*
|
|
* GStreamer
|
|
* Copyright (C) 2008 Filippo Argiolas <filippo.argiolas@gmail.com>
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Library 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
|
|
* Library General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Library General Public
|
|
* License along with this library; if not, write to the
|
|
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
|
|
* Boston, MA 02110-1301, USA.
|
|
*/
|
|
|
|
#if HAVE_CONFIG_H
|
|
#include "config.h"
|
|
#endif
|
|
|
|
#include <gst/gl/gstglconfig.h>
|
|
|
|
#include "../gstgleffects.h"
|
|
#include "gstgleffectssources.h"
|
|
#include <math.h>
|
|
|
|
/* A common file for sources is needed since shader sources can be
|
|
* generic and reused by several effects */
|
|
|
|
/* FIXME */
|
|
/* Move sooner or later into single .frag .vert files and either bake
|
|
* them into a c file at compile time or load them at run time */
|
|
|
|
|
|
/* fill a normalized and zero centered gaussian vector for separable
|
|
* gaussian convolution */
|
|
|
|
void
|
|
fill_gaussian_kernel (float *kernel, int size, float sigma)
|
|
{
|
|
int i;
|
|
float sum;
|
|
int l;
|
|
|
|
/* need an odd sized vector to center it at zero */
|
|
g_return_if_fail ((size % 2) != 0);
|
|
|
|
sum = 0.0;
|
|
l = (size - 1) / 2;
|
|
|
|
for (i = 0; i < size; i++) {
|
|
kernel[i] = expf (-0.5 * pow ((i - l) / sigma, 2.0));
|
|
sum += kernel[i];
|
|
}
|
|
|
|
for (i = 0; i < size; i++) {
|
|
kernel[i] /= sum;
|
|
}
|
|
}
|
|
|
|
/* *INDENT-OFF* */
|
|
|
|
/* Mirror effect */
|
|
const gchar *mirror_fragment_source_opengl =
|
|
"uniform sampler2D tex;"
|
|
"void main () {"
|
|
" vec2 texturecoord = gl_TexCoord[0].xy;"
|
|
" vec2 normcoord;"
|
|
" normcoord = texturecoord - 0.5;"
|
|
" normcoord.x *= sign (normcoord.x);"
|
|
" texturecoord = normcoord + 0.5;"
|
|
" vec4 color = texture2D (tex, texturecoord);"
|
|
" gl_FragColor = color * gl_Color;"
|
|
"}";
|
|
|
|
const gchar *mirror_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"void main () {"
|
|
" vec2 texturecoord = v_texcoord.xy;"
|
|
" float normcoord = texturecoord.x - 0.5;"
|
|
" normcoord *= sign (normcoord);"
|
|
" texturecoord.x = normcoord + 0.5;"
|
|
" gl_FragColor = texture2D (tex, texturecoord);"
|
|
"}";
|
|
|
|
const gchar *squeeze_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"void main () {"
|
|
" vec2 texturecoord = v_texcoord.xy;"
|
|
" vec2 normcoord = texturecoord - 0.5;"
|
|
/* Add a very small value to length otherwise it could be 0 */
|
|
" float r = length (normcoord)+0.01;"
|
|
" r = pow(r, 0.40)*1.3;"
|
|
" normcoord = normcoord / r;"
|
|
" texturecoord = (normcoord + 0.5);"
|
|
" gl_FragColor = texture2D (tex, texturecoord);"
|
|
"}";
|
|
|
|
const gchar *stretch_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"void main () {"
|
|
" vec2 texturecoord = v_texcoord.xy;"
|
|
" vec2 normcoord;"
|
|
" normcoord = texturecoord - 0.5;"
|
|
" float r = length (normcoord);"
|
|
" normcoord *= 2.0 - smoothstep(0.0, 0.35, r);"
|
|
" texturecoord = normcoord + 0.5;"
|
|
" gl_FragColor = texture2D (tex, texturecoord);"
|
|
"}";
|
|
|
|
const gchar *tunnel_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"void main () {"
|
|
" vec2 texturecoord = v_texcoord.xy;"
|
|
" vec2 normcoord;"
|
|
/* little trick with normalized coords to obtain a circle with
|
|
* rect textures */
|
|
" normcoord = (texturecoord - 0.5);"
|
|
" float r = length(normcoord);"
|
|
" if (r > 0.0)"
|
|
" normcoord *= clamp (r, 0.0, 0.275) / r;"
|
|
" texturecoord = normcoord + 0.5;"
|
|
" gl_FragColor = texture2D (tex, texturecoord);"
|
|
"}";
|
|
|
|
const gchar *fisheye_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"void main () {"
|
|
" vec2 texturecoord = v_texcoord.xy;"
|
|
" vec2 normcoord;"
|
|
" normcoord = texturecoord - 0.5;"
|
|
" float r = length (normcoord);"
|
|
" normcoord *= r * 1.41421;" /* sqrt (2) */
|
|
" texturecoord = normcoord + 0.5;"
|
|
" gl_FragColor = texture2D (tex, texturecoord);"
|
|
"}";
|
|
|
|
const gchar *twirl_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"void main () {"
|
|
" vec2 texturecoord = v_texcoord.xy;"
|
|
" vec2 normcoord;"
|
|
" normcoord = texturecoord - 0.5;"
|
|
" float r = length (normcoord);"
|
|
/* calculate rotation angle: maximum (about pi/2) at the origin and
|
|
* gradually decrease it up to 0.6 of each quadrant */
|
|
" float phi = (1.0 - smoothstep (0.0, 0.3, r)) * 1.6;"
|
|
/* precalculate sin phi and cos phi, save some alu */
|
|
" float s = sin(phi);"
|
|
" float c = cos(phi);"
|
|
/* rotate */
|
|
" normcoord *= mat2(c, s, -s, c);"
|
|
" texturecoord = normcoord + 0.5;"
|
|
" gl_FragColor = texture2D (tex, texturecoord);"
|
|
"}";
|
|
|
|
const gchar *bulge_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"void main () {"
|
|
" vec2 texturecoord = v_texcoord.xy;"
|
|
" vec2 normcoord;"
|
|
" normcoord = texturecoord - 0.5;"
|
|
" float r = length (normcoord);"
|
|
" normcoord *= smoothstep (-0.05, 0.25, r);"
|
|
" texturecoord = normcoord + 0.5;"
|
|
" gl_FragColor = texture2D (tex, texturecoord);"
|
|
"}";
|
|
|
|
const gchar *square_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"void main () {"
|
|
" vec2 texturecoord = v_texcoord.xy;"
|
|
" vec2 normcoord;"
|
|
" normcoord = texturecoord - 0.5;"
|
|
" float r = length (normcoord);"
|
|
" normcoord *= 1.0 + smoothstep(0.125, 0.25, abs(normcoord));"
|
|
" normcoord /= 2.0; /* zoom amount */"
|
|
" texturecoord = normcoord + 0.5;"
|
|
" gl_FragColor = texture2D (tex, texturecoord);"
|
|
"}";
|
|
|
|
const gchar *luma_threshold_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"void main () {"
|
|
" vec2 texturecoord = v_texcoord.xy;"
|
|
" vec4 color = texture2D(tex, texturecoord);"
|
|
" float luma = dot(color.rgb, vec3(0.2125, 0.7154, 0.0721));" /* BT.709 (from orange book) */
|
|
" gl_FragColor = vec4 (vec3 (smoothstep (0.30, 0.50, luma)), color.a);"
|
|
"}";
|
|
|
|
const gchar *sep_sobel_length_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"uniform bool invert;"
|
|
"void main () {"
|
|
" vec4 g = texture2D (tex, v_texcoord.xy);"
|
|
/* restore black background with grey edges */
|
|
" g -= vec4(0.5, 0.5, 0.0, 0.0);"
|
|
" float len = length (g);"
|
|
/* little trick to avoid IF operator */
|
|
/* TODO: test if a standalone inverting pass is worth */
|
|
" gl_FragColor = abs(vec4(vec3(float(invert) - len), 1.0));"
|
|
"}";
|
|
|
|
const gchar *desaturate_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"void main () {"
|
|
" vec4 color = texture2D (tex, v_texcoord.xy);"
|
|
" float luma = dot(color.rgb, vec3(0.2125, 0.7154, 0.0721));"
|
|
" gl_FragColor = vec4(vec3(luma), color.a);"
|
|
"}";
|
|
|
|
const gchar *sep_sobel_hconv3_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"uniform float width;"
|
|
"void main () {"
|
|
" float w = 1.0 / width;"
|
|
" vec2 texturecoord[3];"
|
|
" texturecoord[1] = v_texcoord.xy;"
|
|
" texturecoord[0] = texturecoord[1] - vec2(w, 0.0);"
|
|
" texturecoord[2] = texturecoord[1] + vec2(w, 0.0);"
|
|
" float grad_kern[3];"
|
|
" grad_kern[0] = 1.0;"
|
|
" grad_kern[1] = 0.0;"
|
|
" grad_kern[2] = -1.0;"
|
|
" float blur_kern[3];"
|
|
" blur_kern[0] = 0.25;"
|
|
" blur_kern[1] = 0.5;"
|
|
" blur_kern[2] = 0.25;"
|
|
" int i;"
|
|
" vec4 sum = vec4 (0.0);"
|
|
" for (i = 0; i < 3; i++) { "
|
|
" vec4 neighbor = texture2D(tex, texturecoord[i]); "
|
|
" sum.r = neighbor.r * blur_kern[i] + sum.r;"
|
|
" sum.g = neighbor.g * grad_kern[i] + sum.g;"
|
|
" }"
|
|
" gl_FragColor = sum + vec4(0.0, 0.5, 0.0, 0.0);"
|
|
"}";
|
|
|
|
const gchar *sep_sobel_vconv3_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"uniform float height;"
|
|
"void main () {"
|
|
" float h = 1.0 / height;"
|
|
" vec2 texturecoord[3];"
|
|
" texturecoord[1] = v_texcoord.xy;"
|
|
" texturecoord[0] = texturecoord[1] - vec2(0.0, h);"
|
|
" texturecoord[2] = texturecoord[1] + vec2(0.0, h);"
|
|
" float grad_kern[3];"
|
|
" grad_kern[0] = 1.0;"
|
|
" grad_kern[1] = 0.0;"
|
|
" grad_kern[2] = -1.0;"
|
|
" float blur_kern[3];"
|
|
" blur_kern[0] = 0.25;"
|
|
" blur_kern[1] = 0.5;"
|
|
" blur_kern[2] = 0.25;"
|
|
" int i;"
|
|
" vec4 sum = vec4 (0.0);"
|
|
" for (i = 0; i < 3; i++) { "
|
|
" vec4 neighbor = texture2D(tex, texturecoord[i]); "
|
|
" sum.r = neighbor.r * grad_kern[i] + sum.r;"
|
|
" sum.g = neighbor.g * blur_kern[i] + sum.g;"
|
|
" }"
|
|
" gl_FragColor = sum + vec4(0.5, 0.0, 0.0, 0.0);"
|
|
"}";
|
|
|
|
const gchar *hconv7_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"uniform float kernel[7];"
|
|
"uniform float gauss_width;"
|
|
"void main () {"
|
|
" float w = 1.0 / gauss_width;"
|
|
" vec2 texturecoord[7];"
|
|
" texturecoord[3] = v_texcoord.xy;"
|
|
" texturecoord[2] = texturecoord[3] - vec2(w, 0.0);"
|
|
" texturecoord[1] = texturecoord[2] - vec2(w, 0.0);"
|
|
" texturecoord[0] = texturecoord[1] - vec2(w, 0.0);"
|
|
" texturecoord[4] = texturecoord[3] + vec2(w, 0.0);"
|
|
" texturecoord[5] = texturecoord[4] + vec2(w, 0.0);"
|
|
" texturecoord[6] = texturecoord[5] + vec2(w, 0.0);"
|
|
" int i;"
|
|
" vec4 sum = vec4 (0.0);"
|
|
" for (i = 0; i < 7; i++) { "
|
|
" vec4 neighbor = texture2D(tex, texturecoord[i]); "
|
|
" sum += neighbor * kernel[i];"
|
|
" }"
|
|
" gl_FragColor = sum;"
|
|
"}";
|
|
|
|
/* vertical convolution 7x7 */
|
|
const gchar *vconv7_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"uniform float kernel[7];"
|
|
"uniform float gauss_height;"
|
|
"void main () {"
|
|
" float h = 1.0 / gauss_height;"
|
|
" vec2 texturecoord[7];"
|
|
" texturecoord[3] = v_texcoord.xy;"
|
|
" texturecoord[2] = texturecoord[3] - vec2(0.0, h);"
|
|
" texturecoord[1] = texturecoord[2] - vec2(0.0, h);"
|
|
" texturecoord[0] = texturecoord[1] - vec2(0.0, h);"
|
|
" texturecoord[4] = texturecoord[3] + vec2(0.0, h);"
|
|
" texturecoord[5] = texturecoord[4] + vec2(0.0, h);"
|
|
" texturecoord[6] = texturecoord[5] + vec2(0.0, h);"
|
|
" int i;"
|
|
" vec4 sum = vec4 (0.0);"
|
|
" for (i = 0; i < 7; i++) { "
|
|
" vec4 neighbor = texture2D(tex, texturecoord[i]);"
|
|
" sum += neighbor * kernel[i];"
|
|
" }"
|
|
" gl_FragColor = sum;"
|
|
"}";
|
|
|
|
/* TODO: support several blend modes */
|
|
const gchar *sum_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D base;"
|
|
"uniform sampler2D blend;"
|
|
"uniform float alpha;"
|
|
"uniform float beta;"
|
|
"void main () {"
|
|
" vec4 basecolor = texture2D (base, v_texcoord.xy);"
|
|
" vec4 blendcolor = texture2D (blend, v_texcoord.xy);"
|
|
" gl_FragColor = alpha * basecolor + beta * blendcolor;"
|
|
"}";
|
|
|
|
const gchar *multiply_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D base;"
|
|
"uniform sampler2D blend;"
|
|
"uniform float alpha;"
|
|
"void main () {"
|
|
" vec4 basecolor = texture2D (base, v_texcoord.xy);"
|
|
" vec4 blendcolor = texture2D (blend, v_texcoord.xy);"
|
|
" gl_FragColor = (1.0 - alpha) * basecolor + alpha * basecolor * blendcolor;"
|
|
"}";
|
|
|
|
/* lut operations, map luma to tex1d, see orange book (chapter 19) */
|
|
const gchar *luma_to_curve_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"uniform sampler2D curve;"
|
|
"void main () {"
|
|
" vec2 texturecoord = v_texcoord.xy;"
|
|
" vec4 color = texture2D (tex, texturecoord);"
|
|
" float luma = dot(color.rgb, vec3(0.2125, 0.7154, 0.0721));"
|
|
" color = texture2D (curve, vec2(luma, 0.0));"
|
|
" gl_FragColor = color;"
|
|
"}";
|
|
|
|
/* lut operations, map rgb to tex1d, see orange book (chapter 19) */
|
|
const gchar *rgb_to_curve_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"uniform sampler2D curve;"
|
|
"void main () {"
|
|
" vec4 color = texture2D (tex, v_texcoord.xy);"
|
|
" vec4 outcolor;"
|
|
" outcolor.r = texture2D (curve, vec2(color.r, 0.0)).r;"
|
|
" outcolor.g = texture2D (curve, vec2(color.g, 0.0)).g;"
|
|
" outcolor.b = texture2D (curve, vec2(color.b, 0.0)).b;"
|
|
" outcolor.a = color.a;"
|
|
" gl_FragColor = outcolor;"
|
|
"}";
|
|
|
|
const gchar *sin_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"void main () {"
|
|
" vec4 color = texture2D (tex, vec2(v_texcoord.xy));"
|
|
" float luma = dot(color.rgb, vec3(0.2125, 0.7154, 0.0721));"
|
|
/* calculate hue with the Preucil formula */
|
|
" float cosh = color.r - 0.5*(color.g + color.b);"
|
|
/* sqrt(3)/2 = 0.866 */
|
|
" float sinh = 0.866*(color.g - color.b);"
|
|
/* hue = atan2 h */
|
|
" float sch = (1.0-sinh)*cosh;"
|
|
/* ok this is a little trick I came up because I didn't find any
|
|
* detailed proof of the Preucil formula. The issue is that tan(h) is
|
|
* pi-periodic so the smoothstep thing gives both reds (h = 0) and
|
|
* cyans (h = 180). I don't want to use atan since it requires
|
|
* branching and doesn't work on i915. So take only the right half of
|
|
* the circle where cosine is positive */
|
|
/* take a slightly purple color trying to get rid of human skin reds */
|
|
/* tanh = +-1.0 for h = +-45, where yellow=60, magenta=-60 */
|
|
" float a = smoothstep (0.3, 1.0, sch);"
|
|
" float b = smoothstep (-0.4, -0.1, sinh);"
|
|
" float mix = a * b;"
|
|
" gl_FragColor = color * mix + luma * (1.0 - mix);"
|
|
"}";
|
|
|
|
const gchar *interpolate_fragment_source =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D base;"
|
|
"uniform sampler2D blend;"
|
|
"void main () {"
|
|
"vec4 basecolor = texture2D (base, v_texcoord);"
|
|
"vec4 blendcolor = texture2D (blend, v_texcoord);"
|
|
"vec4 white = vec4(1.0);"
|
|
"gl_FragColor = blendcolor + (1.0 - blendcolor.a) * basecolor;"
|
|
"}";
|
|
|
|
const gchar *texture_interp_fragment_source =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D base;"
|
|
"uniform sampler2D blend;"
|
|
"uniform sampler2D alpha;"
|
|
"void main () {"
|
|
" vec4 basecolor = texture2D (base, v_texcoord);"
|
|
" vec4 blendcolor = texture2D (blend, v_texcoord);"
|
|
" vec4 alphacolor = texture2D (alpha, v_texcoord);"
|
|
" gl_FragColor = (alphacolor * blendcolor) + (1.0 - alphacolor) * basecolor;"
|
|
"}";
|
|
|
|
const gchar *difference_fragment_source =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D saved;"
|
|
"uniform sampler2D current;"
|
|
"void main () {"
|
|
"vec4 savedcolor = texture2D (saved, v_texcoord);"
|
|
"vec4 currentcolor = texture2D (current, v_texcoord);"
|
|
"gl_FragColor = vec4 (step (0.12, length (savedcolor - currentcolor)));"
|
|
"}";
|
|
|
|
/* This filter is meant as a demo of gst-plugins-gl + glsl
|
|
capabilities. So I'm keeping this shader readable enough. If and
|
|
when this shader will be used in production be careful to hard code
|
|
kernel into the shader and remove unneeded zero multiplications in
|
|
the convolution */
|
|
const gchar *conv9_fragment_source_gles2 =
|
|
"#ifdef GL_ES\n"
|
|
"precision mediump float;\n"
|
|
"#endif\n"
|
|
"varying vec2 v_texcoord;"
|
|
"uniform sampler2D tex;"
|
|
"uniform float kernel[9];"
|
|
"uniform float width, height;"
|
|
"uniform bool invert;"
|
|
"void main () {"
|
|
" float w = 1.0 / width;"
|
|
" float h = 1.0 / height;"
|
|
" vec2 texturecoord[9];"
|
|
" texturecoord[4] = v_texcoord.xy;" /* 0 0 */
|
|
" texturecoord[5] = texturecoord[4] + vec2(w, 0.0);" /* 1 0 */
|
|
" texturecoord[2] = texturecoord[5] - vec2(0.0, h);" /* 1 -1 */
|
|
" texturecoord[1] = texturecoord[2] - vec2(w, 0.0);" /* 0 -1 */
|
|
" texturecoord[0] = texturecoord[1] - vec2(w, 0.0);" /* -1 -1 */
|
|
" texturecoord[3] = texturecoord[0] + vec2(0.0, h);" /* -1 0 */
|
|
" texturecoord[6] = texturecoord[3] + vec2(0.0, h);" /* -1 1 */
|
|
" texturecoord[7] = texturecoord[6] + vec2(w, 0.0);" /* 0 1 */
|
|
" texturecoord[8] = texturecoord[7] + vec2(w, 0.0);" /* 1 1 */
|
|
" int i;"
|
|
" vec3 sum = vec3 (0.0);"
|
|
" for (i = 0; i < 9; i++) { "
|
|
" vec4 neighbor = texture2D (tex, texturecoord[i]);"
|
|
" sum += neighbor.xyz * kernel[i];"
|
|
" }"
|
|
" gl_FragColor = vec4 (abs(sum - vec3(float(invert))), 1.0);"
|
|
"}";
|
|
|
|
/* *INDENT-ON* */
|