godot/drivers/gles2/shaders/lens_distorted.glsl
Rémi Verschelde 57416bfbce GLES2: Define 'lowp' for OpenGL 2.1
Precision qualifiers are only used on OpenGL ES 2.0 and 3.0,
and while OpenGL 3.3 defines them for compatibility (but without
practical effect), they're missing from OpenGL 2.1, so we define
them to prevent compilation errors.

Fixes #24521.
2018-12-21 15:14:58 +01:00

81 lines
1.5 KiB
GLSL

/* clang-format off */
[vertex]
#ifdef USE_GLES_OVER_GL
#define lowp
#define mediump
#define highp
#else
precision highp float;
precision highp int;
#endif
attribute highp vec2 vertex; // attrib:0
/* clang-format on */
uniform vec2 offset;
uniform vec2 scale;
varying vec2 uv_interp;
void main() {
uv_interp = vertex.xy * 2.0 - 1.0;
vec2 v = vertex.xy * scale + offset;
gl_Position = vec4(v, 0.0, 1.0);
}
/* clang-format off */
[fragment]
#ifdef USE_GLES_OVER_GL
#define lowp
#define mediump
#define highp
#else
precision mediump float;
precision highp int;
#endif
uniform sampler2D source; //texunit:0
/* clang-format on */
uniform vec2 eye_center;
uniform float k1;
uniform float k2;
uniform float upscale;
uniform float aspect_ratio;
varying vec2 uv_interp;
void main() {
vec2 coords = uv_interp;
vec2 offset = coords - eye_center;
// take aspect ratio into account
offset.y /= aspect_ratio;
// distort
vec2 offset_sq = offset * offset;
float radius_sq = offset_sq.x + offset_sq.y;
float radius_s4 = radius_sq * radius_sq;
float distortion_scale = 1.0 + (k1 * radius_sq) + (k2 * radius_s4);
offset *= distortion_scale;
// reapply aspect ratio
offset.y *= aspect_ratio;
// add our eye center back in
coords = offset + eye_center;
coords /= upscale;
// and check our color
if (coords.x < -1.0 || coords.y < -1.0 || coords.x > 1.0 || coords.y > 1.0) {
gl_FragColor = vec4(0.0, 0.0, 0.0, 1.0);
} else {
coords = (coords + vec2(1.0)) / vec2(2.0);
gl_FragColor = texture2D(source, coords);
}
}