gg: roundrects

vlib/gg/utils.v

@@ -0,0 +1,39 @@
+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)
+}