virtualx-engine/drivers/gles2/shaders/cube_to_dp.glsl
karroffel eac4c984df add GLES 2 renderer for 2D
This commit adds a new rendering backend, GLES2, and adds a
project setting to enable it.

Currently this backend can only be used on the X11 platform,
but integrating into other platforms is planned.
2018-03-01 15:12:30 +01:00

79 lines
1.8 KiB
GLSL

[vertex]
layout(location=0) in highp vec4 vertex_attrib;
layout(location=4) in vec2 uv_in;
out vec2 uv_interp;
void main() {
uv_interp = uv_in;
gl_Position = vertex_attrib;
}
[fragment]
uniform highp samplerCube source_cube; //texunit:0
in vec2 uv_interp;
uniform bool z_flip;
uniform highp float z_far;
uniform highp float z_near;
uniform highp float bias;
void main() {
highp vec3 normal = vec3( uv_interp * 2.0 - 1.0, 0.0 );
/*
if(z_flip) {
normal.z = 0.5 - 0.5*((normal.x * normal.x) + (normal.y * normal.y));
} else {
normal.z = -0.5 + 0.5*((normal.x * normal.x) + (normal.y * normal.y));
}
*/
//normal.z = sqrt(1.0-dot(normal.xy,normal.xy));
//normal.xy*=1.0+normal.z;
normal.z = 0.5 - 0.5*((normal.x * normal.x) + (normal.y * normal.y));
normal = normalize(normal);
/*
normal.z=0.5;
normal=normalize(normal);
*/
if (!z_flip) {
normal.z=-normal.z;
}
//normal = normalize(vec3( uv_interp * 2.0 - 1.0, 1.0 ));
float depth = texture(source_cube,normal).r;
// absolute values for direction cosines, bigger value equals closer to basis axis
vec3 unorm = abs(normal);
if ( (unorm.x >= unorm.y) && (unorm.x >= unorm.z) ) {
// x code
unorm = normal.x > 0.0 ? vec3( 1.0, 0.0, 0.0 ) : vec3( -1.0, 0.0, 0.0 ) ;
} else if ( (unorm.y > unorm.x) && (unorm.y >= unorm.z) ) {
// y code
unorm = normal.y > 0.0 ? vec3( 0.0, 1.0, 0.0 ) : vec3( 0.0, -1.0, 0.0 ) ;
} else if ( (unorm.z > unorm.x) && (unorm.z > unorm.y) ) {
// z code
unorm = normal.z > 0.0 ? vec3( 0.0, 0.0, 1.0 ) : vec3( 0.0, 0.0, -1.0 ) ;
} else {
// oh-no we messed up code
// has to be
unorm = vec3( 1.0, 0.0, 0.0 );
}
float depth_fix = 1.0 / dot(normal,unorm);
depth = 2.0 * depth - 1.0;
float linear_depth = 2.0 * z_near * z_far / (z_far + z_near - depth * (z_far - z_near));
gl_FragDepth = (linear_depth*depth_fix+bias) / z_far;
}