func initGL() {
var err error
program, err = glutil.CreateProgram(vertexShader, fragmentShader)
if err != nil {
log.Printf("error creating GL program: %v", err)
return
}
buf = gl.GenBuffer()
gl.BindBuffer(gl.ARRAY_BUFFER, buf)
gl.BufferData(gl.ARRAY_BUFFER, gl.STATIC_DRAW, triangleData)
position = gl.GetAttribLocation(program, "position")
color = gl.GetUniformLocation(program, "color")
offset = gl.GetUniformLocation(program, "offset")
touchLoc = geom.Point{geom.Width / 2, geom.Height / 2}
}
func initKeys() {
var err error
program, err = glutil.CreateProgram(
`#version 100
uniform mat4 projection;
attribute vec3 position;
attribute float pointsize;
void main() {
gl_Position = projection * vec4(position, 1);
gl_PointSize = pointsize;
}`,
`#version 100
precision mediump float;
uniform vec4 color;
void main(void)
{
vec2 v = 2.0*gl_PointCoord.xy - vec2(1.0);
float r2 = dot(v, v);
gl_FragColor = mix(color, vec4(0), r2);
}`,
)
if err != nil {
log.Printf("error creating GL program: %v", err)
return
}
gl.Enable(34370) // GL_PROGRAM_POINT_SIZE; apparently not necessary on Android
gl.Enable(gl.BLEND)
gl.BlendFunc(gl.ONE, gl.ONE_MINUS_SRC_COLOR)
projection = gl.GetUniformLocation(program, "projection")
updateProjectionMatrix()
position = gl.GetAttribLocation(program, "position")
pointsize = gl.GetAttribLocation(program, "pointsize")
color = gl.GetUniformLocation(program, "color")
positionbuf = gl.CreateBuffer()
pointsizebuf = gl.CreateBuffer()
updateKeys(ratio{1, 1})
}