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v/vlib/gg/utils.v
2020-01-31 03:43:46 +01:00

40 lines
1.0 KiB
V

module gg
import (
gl
gx
math
)
fn arc_vertices(x, y, r, start_angle, end_angle f32, segments int) []f32 {
mut vertices := []f32
start_rads := start_angle * 0.0174533 // deg -> rad approx
end_rads := end_angle * 0.0174533
increment := (end_rads - start_rads) / segments
vertices << [x + f32(math.cos(start_rads)) * r, y + f32(math.sin(start_rads)) * r]
mut i := 1
for i < segments {
theta := f32(i) * increment + start_rads
vertices << [x + f32(math.cos(theta)) * r, y + f32(math.sin(theta)) * r]
i++
}
vertices << [x + f32(math.cos(end_rads)) * r, y + f32(math.sin(end_rads)) * r]
return vertices
}
fn (ctx &GG) use_color_shader(color gx.Color) {
ctx.shader.set_int('has_texture', 0)
C.glDeleteBuffers(1, &ctx.vao)
C.glDeleteBuffers(1, &ctx.vbo)
ctx.shader.use()
ctx.shader.set_color('color', color)
}
fn (ctx &GG) bind_vertices(vertices []f32) {
gl.bind_vao(ctx.vao)
gl.set_vbo(ctx.vbo, vertices, C.GL_STATIC_DRAW)
gl.vertex_attrib_pointer(0, 2, C.GL_FLOAT, false, 2, 0)
gl.enable_vertex_attrib_array(0)
gl.bind_vao(ctx.vao)
}